cassandra-trunk/src/java/org/apache/cassandra/service/StorageService.java
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.cassandra.service;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOError;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.time.Instant;
import java.time.format.DateTimeParseException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Optional;
import java.util.Scanner;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Supplier;
import java.util.regex.MatchResult;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import javax.annotation.Nullable;
import javax.management.ListenerNotFoundException;
import javax.management.NotificationBroadcasterSupport;
import javax.management.NotificationFilter;
import javax.management.NotificationListener;
import javax.management.openmbean.CompositeData;
import javax.management.openmbean.OpenDataException;
import javax.management.openmbean.TabularData;
import javax.management.openmbean.TabularDataSupport;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Joiner;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Multimap;
import com.google.common.collect.Ordering;
import com.google.common.collect.Sets;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.RateLimiter;
import com.google.common.util.concurrent.Uninterruptibles;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.cassandra.audit.AuditLogManager;
import org.apache.cassandra.audit.AuditLogOptions;
import org.apache.cassandra.auth.AuthCacheService;
import org.apache.cassandra.auth.AuthKeyspace;
import org.apache.cassandra.auth.AuthSchemaChangeListener;
import org.apache.cassandra.batchlog.BatchlogManager;
import org.apache.cassandra.concurrent.ExecutorLocals;
import org.apache.cassandra.concurrent.FutureTask;
import org.apache.cassandra.concurrent.FutureTaskWithResources;
import org.apache.cassandra.concurrent.NamedThreadFactory;
import org.apache.cassandra.concurrent.ScheduledExecutors;
import org.apache.cassandra.concurrent.Stage;
import org.apache.cassandra.config.CassandraRelevantProperties;
import org.apache.cassandra.config.Config;
import org.apache.cassandra.config.Config.PaxosStatePurging;
import org.apache.cassandra.config.Converters;
import org.apache.cassandra.config.DataStorageSpec;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.config.DurationSpec;
import org.apache.cassandra.cql3.QueryHandler;
import org.apache.cassandra.cql3.QueryProcessor;
import org.apache.cassandra.db.ColumnFamilyStore;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.db.Keyspace;
import org.apache.cassandra.db.SizeEstimatesRecorder;
import org.apache.cassandra.db.SnapshotDetailsTabularData;
import org.apache.cassandra.db.SystemKeyspace;
import org.apache.cassandra.db.commitlog.CommitLog;
import org.apache.cassandra.db.compaction.CompactionManager;
import org.apache.cassandra.db.compaction.OperationType;
import org.apache.cassandra.db.guardrails.Guardrails;
import org.apache.cassandra.db.lifecycle.LifecycleTransaction;
import org.apache.cassandra.db.virtual.VirtualKeyspaceRegistry;
import org.apache.cassandra.dht.BootStrapper;
import org.apache.cassandra.dht.IPartitioner;
import org.apache.cassandra.dht.Range;
import org.apache.cassandra.dht.RangeStreamer;
import org.apache.cassandra.dht.RangeStreamer.FetchReplica;
import org.apache.cassandra.dht.StreamStateStore;
import org.apache.cassandra.dht.Token;
import org.apache.cassandra.dht.Token.TokenFactory;
import org.apache.cassandra.exceptions.ConfigurationException;
import org.apache.cassandra.exceptions.InvalidRequestException;
import org.apache.cassandra.exceptions.UnavailableException;
import org.apache.cassandra.fql.FullQueryLogger;
import org.apache.cassandra.fql.FullQueryLoggerOptions;
import org.apache.cassandra.fql.FullQueryLoggerOptionsCompositeData;
import org.apache.cassandra.gms.ApplicationState;
import org.apache.cassandra.gms.EndpointState;
import org.apache.cassandra.gms.FailureDetector;
import org.apache.cassandra.gms.Gossiper;
import org.apache.cassandra.gms.IEndpointStateChangeSubscriber;
import org.apache.cassandra.gms.IFailureDetector;
import org.apache.cassandra.gms.TokenSerializer;
import org.apache.cassandra.gms.VersionedValue;
import org.apache.cassandra.hints.HintsService;
import org.apache.cassandra.io.sstable.IScrubber;
import org.apache.cassandra.io.sstable.IVerifier;
import org.apache.cassandra.io.sstable.SSTableLoader;
import org.apache.cassandra.io.sstable.format.Version;
import org.apache.cassandra.io.util.File;
import org.apache.cassandra.io.util.FileUtils;
import org.apache.cassandra.io.util.PathUtils;
import org.apache.cassandra.locator.AbstractReplicationStrategy;
import org.apache.cassandra.locator.DynamicEndpointSnitch;
import org.apache.cassandra.locator.EndpointsByRange;
import org.apache.cassandra.locator.EndpointsByReplica;
import org.apache.cassandra.locator.EndpointsForRange;
import org.apache.cassandra.locator.EndpointsForToken;
import org.apache.cassandra.locator.IEndpointSnitch;
import org.apache.cassandra.locator.InetAddressAndPort;
import org.apache.cassandra.locator.LocalStrategy;
import org.apache.cassandra.locator.NetworkTopologyStrategy;
import org.apache.cassandra.locator.RangesAtEndpoint;
import org.apache.cassandra.locator.RangesByEndpoint;
import org.apache.cassandra.locator.Replica;
import org.apache.cassandra.locator.ReplicaCollection.Builder.Conflict;
import org.apache.cassandra.locator.Replicas;
import org.apache.cassandra.locator.SystemReplicas;
import org.apache.cassandra.locator.TokenMetadata;
import org.apache.cassandra.metrics.Sampler;
import org.apache.cassandra.metrics.SamplingManager;
import org.apache.cassandra.metrics.StorageMetrics;
import org.apache.cassandra.net.AsyncOneResponse;
import org.apache.cassandra.net.Message;
import org.apache.cassandra.net.MessagingService;
import org.apache.cassandra.repair.RepairRunnable;
import org.apache.cassandra.repair.messages.RepairOption;
import org.apache.cassandra.schema.CompactionParams.TombstoneOption;
import org.apache.cassandra.schema.KeyspaceMetadata;
import org.apache.cassandra.schema.Keyspaces;
import org.apache.cassandra.schema.ReplicationParams;
import org.apache.cassandra.schema.Schema;
import org.apache.cassandra.schema.SchemaConstants;
import org.apache.cassandra.schema.SchemaTransformations;
import org.apache.cassandra.schema.SystemDistributedKeyspace;
import org.apache.cassandra.schema.TableId;
import org.apache.cassandra.schema.TableMetadata;
import org.apache.cassandra.schema.TableMetadataRef;
import org.apache.cassandra.schema.ViewMetadata;
import org.apache.cassandra.service.disk.usage.DiskUsageBroadcaster;
import org.apache.cassandra.service.paxos.Paxos;
import org.apache.cassandra.service.paxos.PaxosCommit;
import org.apache.cassandra.service.paxos.PaxosRepair;
import org.apache.cassandra.service.paxos.PaxosState;
import org.apache.cassandra.service.paxos.cleanup.PaxosCleanupLocalCoordinator;
import org.apache.cassandra.service.paxos.cleanup.PaxosTableRepairs;
import org.apache.cassandra.service.snapshot.SnapshotManager;
import org.apache.cassandra.service.snapshot.TableSnapshot;
import org.apache.cassandra.streaming.StreamManager;
import org.apache.cassandra.streaming.StreamOperation;
import org.apache.cassandra.streaming.StreamPlan;
import org.apache.cassandra.streaming.StreamResultFuture;
import org.apache.cassandra.streaming.StreamState;
import org.apache.cassandra.tracing.TraceKeyspace;
import org.apache.cassandra.transport.ClientResourceLimits;
import org.apache.cassandra.transport.ProtocolVersion;
import org.apache.cassandra.utils.Clock;
import org.apache.cassandra.utils.ExecutorUtils;
import org.apache.cassandra.utils.FBUtilities;
import org.apache.cassandra.utils.JVMStabilityInspector;
import org.apache.cassandra.utils.MBeanWrapper;
import org.apache.cassandra.utils.MD5Digest;
import org.apache.cassandra.utils.OutputHandler;
import org.apache.cassandra.utils.Pair;
import org.apache.cassandra.utils.Throwables;
import org.apache.cassandra.utils.WrappedRunnable;
import org.apache.cassandra.utils.concurrent.Future;
import org.apache.cassandra.utils.concurrent.FutureCombiner;
import org.apache.cassandra.utils.concurrent.ImmediateFuture;
import org.apache.cassandra.utils.concurrent.UncheckedInterruptedException;
import org.apache.cassandra.utils.logging.LoggingSupportFactory;
import org.apache.cassandra.utils.progress.ProgressEvent;
import org.apache.cassandra.utils.progress.ProgressEventType;
import org.apache.cassandra.utils.progress.ProgressListener;
import org.apache.cassandra.utils.progress.jmx.JMXBroadcastExecutor;
import org.apache.cassandra.utils.progress.jmx.JMXProgressSupport;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.Iterables.transform;
import static com.google.common.collect.Iterables.tryFind;
import static java.util.Arrays.asList;
import static java.util.Arrays.stream;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.MINUTES;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;
import static java.util.stream.Collectors.toList;
import static java.util.stream.Collectors.toMap;
import static org.apache.cassandra.config.CassandraRelevantProperties.ALLOW_UNSAFE_JOIN;
import static org.apache.cassandra.config.CassandraRelevantProperties.ALLOW_UNSAFE_REPLACE;
import static org.apache.cassandra.config.CassandraRelevantProperties.BOOTSTRAP_SCHEMA_DELAY_MS;
import static org.apache.cassandra.config.CassandraRelevantProperties.BOOTSTRAP_SKIP_SCHEMA_CHECK;
import static org.apache.cassandra.config.CassandraRelevantProperties.CONSISTENT_RANGE_MOVEMENT;
import static org.apache.cassandra.config.CassandraRelevantProperties.CONSISTENT_SIMULTANEOUS_MOVES_ALLOW;
import static org.apache.cassandra.config.CassandraRelevantProperties.DRAIN_EXECUTOR_TIMEOUT_MS;
import static org.apache.cassandra.config.CassandraRelevantProperties.JOIN_RING;
import static org.apache.cassandra.config.CassandraRelevantProperties.LOAD_RING_STATE;
import static org.apache.cassandra.config.CassandraRelevantProperties.OVERRIDE_DECOMMISSION;
import static org.apache.cassandra.config.CassandraRelevantProperties.PAXOS_REPAIR_ON_TOPOLOGY_CHANGE_RETRIES;
import static org.apache.cassandra.config.CassandraRelevantProperties.PAXOS_REPAIR_ON_TOPOLOGY_CHANGE_RETRY_DELAY_SECONDS;
import static org.apache.cassandra.config.CassandraRelevantProperties.REPLACEMENT_ALLOW_EMPTY;
import static org.apache.cassandra.config.CassandraRelevantProperties.REPLACE_ADDRESS;
import static org.apache.cassandra.config.CassandraRelevantProperties.REPLACE_ADDRESS_FIRST_BOOT;
import static org.apache.cassandra.config.CassandraRelevantProperties.RESET_BOOTSTRAP_PROGRESS;
import static org.apache.cassandra.config.CassandraRelevantProperties.START_GOSSIP;
import static org.apache.cassandra.config.CassandraRelevantProperties.TEST_WRITE_SURVEY;
import static org.apache.cassandra.index.SecondaryIndexManager.getIndexName;
import static org.apache.cassandra.index.SecondaryIndexManager.isIndexColumnFamily;
import static org.apache.cassandra.net.NoPayload.noPayload;
import static org.apache.cassandra.net.Verb.REPLICATION_DONE_REQ;
import static org.apache.cassandra.service.ActiveRepairService.ParentRepairStatus;
import static org.apache.cassandra.service.ActiveRepairService.repairCommandExecutor;
import static org.apache.cassandra.service.StorageService.Mode.DECOMMISSIONED;
import static org.apache.cassandra.service.StorageService.Mode.DECOMMISSION_FAILED;
import static org.apache.cassandra.utils.Clock.Global.currentTimeMillis;
import static org.apache.cassandra.utils.Clock.Global.nanoTime;
import static org.apache.cassandra.utils.FBUtilities.getBroadcastAddressAndPort;
import static org.apache.cassandra.utils.FBUtilities.now;

/**
 * This abstraction contains the token/identifier of this node
 * on the identifier space. This token gets gossiped around.
 * This class will also maintain histograms of the load information
 * of other nodes in the cluster.
 */
public class StorageService extends NotificationBroadcasterSupport implements IEndpointStateChangeSubscriber, StorageServiceMBean
{
    private static final Logger logger = LoggerFactory.getLogger(StorageService.class);

    public static final int INDEFINITE = -1;
    public static final int RING_DELAY_MILLIS = getRingDelay(); // delay after which we assume ring has stablized
    public static final int SCHEMA_DELAY_MILLIS = getSchemaDelay();

    private static final boolean REQUIRE_SCHEMAS = !BOOTSTRAP_SKIP_SCHEMA_CHECK.getBoolean();

    private final JMXProgressSupport progressSupport = new JMXProgressSupport(this);

    private static int getRingDelay()
    {
        String newdelay = CassandraRelevantProperties.RING_DELAY.getString();
        if (newdelay != null)
        {
            logger.info("Overriding RING_DELAY to {}ms", newdelay);
            return Integer.parseInt(newdelay);
        }
        else
        {
            return 30 * 1000;
        }
    }

    private static int getSchemaDelay()
    {
        String newdelay = BOOTSTRAP_SCHEMA_DELAY_MS.getString();
        if (newdelay != null)
        {
            logger.info("Overriding SCHEMA_DELAY_MILLIS to {}ms", newdelay);
            return Integer.parseInt(newdelay);
        }
        else
        {
            return 30 * 1000;
        }
    }

    /* This abstraction maintains the token/endpoint metadata information */
    private TokenMetadata tokenMetadata = new TokenMetadata();

    public volatile VersionedValue.VersionedValueFactory valueFactory = new VersionedValue.VersionedValueFactory(tokenMetadata.partitioner);

    private Thread drainOnShutdown = null;
    private volatile boolean isShutdown = false;
    private final List<Runnable> preShutdownHooks = new ArrayList<>();
    private final List<Runnable> postShutdownHooks = new ArrayList<>();

    public final SnapshotManager snapshotManager = new SnapshotManager();

    public static final StorageService instance = new StorageService();

    private final SamplingManager samplingManager = new SamplingManager();

    @VisibleForTesting // this is used for dtests only, see CASSANDRA-18152
    public volatile boolean skipNotificationListeners = false;

    @Deprecated
    public boolean isInShutdownHook()
    {
        return isShutdown();
    }

    public boolean isShutdown()
    {
        return isShutdown;
    }

    /**
     * for in-jvm dtest use - forces isShutdown to be set to whatever passed in.
     */
    @VisibleForTesting
    public void setIsShutdownUnsafeForTests(boolean isShutdown)
    {
        this.isShutdown = isShutdown;
    }

    public RangesAtEndpoint getLocalReplicas(String keyspaceName)
    {
        return Keyspace.open(keyspaceName).getReplicationStrategy()
                .getAddressReplicas(FBUtilities.getBroadcastAddressAndPort());
    }

    public List<Range<Token>> getLocalRanges(String ks)
    {
        InetAddressAndPort broadcastAddress = FBUtilities.getBroadcastAddressAndPort();
        Keyspace keyspace = Keyspace.open(ks);
        List<Range<Token>> ranges = new ArrayList<>();
        for (Replica r : keyspace.getReplicationStrategy().getAddressReplicas(broadcastAddress))
            ranges.add(r.range());
        return ranges;
    }

    public List<Range<Token>> getLocalAndPendingRanges(String ks)
    {
        InetAddressAndPort broadcastAddress = FBUtilities.getBroadcastAddressAndPort();
        Keyspace keyspace = Keyspace.open(ks);
        List<Range<Token>> ranges = new ArrayList<>();
        for (Replica r : keyspace.getReplicationStrategy().getAddressReplicas(broadcastAddress))
            ranges.add(r.range());
        for (Replica r : getTokenMetadata().getPendingRanges(ks, broadcastAddress))
            ranges.add(r.range());
        return ranges;
    }

    public Collection<Range<Token>> getPrimaryRanges(String keyspace)
    {
        return getPrimaryRangesForEndpoint(keyspace, FBUtilities.getBroadcastAddressAndPort());
    }

    public Collection<Range<Token>> getPrimaryRangesWithinDC(String keyspace)
    {
        return getPrimaryRangeForEndpointWithinDC(keyspace, FBUtilities.getBroadcastAddressAndPort());
    }

    private final Set<InetAddressAndPort> replicatingNodes = Sets.newConcurrentHashSet();
    private CassandraDaemon daemon;

    private InetAddressAndPort removingNode;

    /* Are we starting this node in bootstrap mode? */
    private volatile boolean isBootstrapMode;

    /* we bootstrap but do NOT join the ring unless told to do so */
    private boolean isSurveyMode = TEST_WRITE_SURVEY.getBoolean(false);
    /* true if node is rebuilding and receiving data */
    private final AtomicBoolean isRebuilding = new AtomicBoolean();
    private final AtomicBoolean isDecommissioning = new AtomicBoolean();

    private volatile boolean initialized = false;
    private volatile boolean joined = false;
    private volatile boolean gossipActive = false;
    private final AtomicBoolean authSetupCalled = new AtomicBoolean(false);
    private volatile boolean authSetupComplete = false;

    /* the probability for tracing any particular request, 0 disables tracing and 1 enables for all */
    private double traceProbability = 0.0;

    public enum Mode { STARTING, NORMAL, JOINING, LEAVING, DECOMMISSIONED, DECOMMISSION_FAILED, MOVING, DRAINING, DRAINED }
    private volatile Mode operationMode = Mode.STARTING;

    /* Used for tracking drain progress */
    private volatile int totalCFs, remainingCFs;

    private static final AtomicInteger nextRepairCommand = new AtomicInteger();

    private final List<IEndpointLifecycleSubscriber> lifecycleSubscribers = new CopyOnWriteArrayList<>();

    private final String jmxObjectName;

    private Collection<Token> bootstrapTokens = null;

    // true when keeping strict consistency while bootstrapping
    public static final boolean useStrictConsistency = CONSISTENT_RANGE_MOVEMENT.getBoolean();
    private static final boolean allowSimultaneousMoves = CONSISTENT_SIMULTANEOUS_MOVES_ALLOW.getBoolean();
    private static final boolean joinRing = JOIN_RING.getBoolean();
    private boolean replacing;

    private final StreamStateStore streamStateStore = new StreamStateStore();

    public final SSTablesGlobalTracker sstablesTracker;

    public boolean isSurveyMode()
    {
        return isSurveyMode;
    }

    public boolean hasJoined()
    {
        return joined;
    }

    /**
     * This method updates the local token on disk
     */
    public void setTokens(Collection<Token> tokens)
    {
        assert tokens != null && !tokens.isEmpty() : "Node needs at least one token.";
        if (logger.isDebugEnabled())
            logger.debug("Setting tokens to {}", tokens);
        SystemKeyspace.updateTokens(tokens);
        Collection<Token> localTokens = getLocalTokens();
        setGossipTokens(localTokens);
        tokenMetadata.updateNormalTokens(tokens, FBUtilities.getBroadcastAddressAndPort());
        setMode(Mode.NORMAL, false);
        invalidateLocalRanges();
    }

    public void setGossipTokens(Collection<Token> tokens)
    {
        List<Pair<ApplicationState, VersionedValue>> states = new ArrayList<Pair<ApplicationState, VersionedValue>>();
        states.add(Pair.create(ApplicationState.TOKENS, valueFactory.tokens(tokens)));
        states.add(Pair.create(ApplicationState.STATUS_WITH_PORT, valueFactory.normal(tokens)));
        states.add(Pair.create(ApplicationState.STATUS, valueFactory.normal(tokens)));
        Gossiper.instance.addLocalApplicationStates(states);
    }

    public StorageService()
    {
        // use dedicated executor for handling JMX notifications
        super(JMXBroadcastExecutor.executor);

        jmxObjectName = "org.apache.cassandra.db:type=StorageService";

        sstablesTracker = new SSTablesGlobalTracker(DatabaseDescriptor.getSelectedSSTableFormat());
    }

    private void registerMBeans()
    {
        MBeanWrapper.instance.registerMBean(this, jmxObjectName);
        MBeanWrapper.instance.registerMBean(StreamManager.instance, StreamManager.OBJECT_NAME);
    }

    public void registerDaemon(CassandraDaemon daemon)
    {
        this.daemon = daemon;
    }

    public void register(IEndpointLifecycleSubscriber subscriber)
    {
        lifecycleSubscribers.add(subscriber);
    }

    public void unregister(IEndpointLifecycleSubscriber subscriber)
    {
        lifecycleSubscribers.remove(subscriber);
    }

    // should only be called via JMX
    public void stopGossiping()
    {
        if (gossipActive)
        {
            if (!isNormal() && joinRing)
                throw new IllegalStateException("Unable to stop gossip because the node is not in the normal state. Try to stop the node instead.");

            logger.warn("Stopping gossip by operator request");

            if (isNativeTransportRunning())
            {
                logger.warn("Disabling gossip while native transport is still active is unsafe");
            }

            Gossiper.instance.stop();
            gossipActive = false;
        }
    }

    // should only be called via JMX
    public synchronized void startGossiping()
    {
        if (!gossipActive)
        {
            checkServiceAllowedToStart("gossip");

            logger.warn("Starting gossip by operator request");
            Collection<Token> tokens = SystemKeyspace.getSavedTokens();

            boolean validTokens = tokens != null && !tokens.isEmpty();

            // shouldn't be called before these are set if we intend to join the ring/are in the process of doing so
            if (joined || joinRing)
                assert validTokens : "Cannot start gossiping for a node intended to join without valid tokens";

            if (validTokens)
                setGossipTokens(tokens);

            Gossiper.instance.forceNewerGeneration();
            Gossiper.instance.start((int) (currentTimeMillis() / 1000));
            gossipActive = true;
        }
    }

    // should only be called via JMX
    public boolean isGossipRunning()
    {
        return Gossiper.instance.isEnabled();
    }

    public synchronized void startNativeTransport()
    {
        checkServiceAllowedToStart("native transport");

        if (daemon == null)
        {
            throw new IllegalStateException("No configured daemon");
        }

        try
        {
            daemon.startNativeTransport();
        }
        catch (Exception e)
        {
            throw new RuntimeException("Error starting native transport: " + e.getMessage());
        }
    }

    public void stopNativeTransport()
    {
        if (daemon == null)
        {
            throw new IllegalStateException("No configured daemon");
        }
        daemon.stopNativeTransport();
    }

    public boolean isNativeTransportRunning()
    {
        if (daemon == null)
        {
            return false;
        }
        return daemon.isNativeTransportRunning();
    }

    @Override
    public void enableNativeTransportOldProtocolVersions()
    {
        DatabaseDescriptor.setNativeTransportAllowOlderProtocols(true);
    }

    @Override
    public void disableNativeTransportOldProtocolVersions()
    {
        DatabaseDescriptor.setNativeTransportAllowOlderProtocols(false);
    }

    public void stopTransports()
    {
        if (isNativeTransportRunning())
        {
            logger.error("Stopping native transport");
            stopNativeTransport();
        }
        if (isGossipActive())
        {
            logger.error("Stopping gossiper");
            stopGossiping();
        }
    }

    /**
     * Set the Gossip flag RPC_READY to false and then
     * shutdown the client services (thrift and CQL).
     *
     * Note that other nodes will do this for us when
     * they get the Gossip shutdown message, so even if
     * we don't get time to broadcast this, it is not a problem.
     *
     * See Gossiper.markAsShutdown(InetAddressAndPort)
     */
    private void shutdownClientServers()
    {
        setRpcReady(false);
        stopNativeTransport();
    }

    public void stopClient()
    {
        Gossiper.instance.unregister(this);
        Gossiper.instance.stop();
        MessagingService.instance().shutdown();
        // give it a second so that task accepted before the MessagingService shutdown gets submitted to the stage (to avoid RejectedExecutionException)
        Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
        Stage.shutdownNow();
    }

    public boolean isInitialized()
    {
        return initialized;
    }

    public boolean isGossipActive()
    {
        return gossipActive;
    }

    public boolean isDaemonSetupCompleted()
    {
        return daemon != null && daemon.setupCompleted();
    }

    public void stopDaemon()
    {
        if (daemon == null)
            throw new IllegalStateException("No configured daemon");
        daemon.deactivate();
    }

    private synchronized UUID prepareForReplacement() throws ConfigurationException
    {
        if (SystemKeyspace.bootstrapComplete())
            throw new RuntimeException("Cannot replace address with a node that is already bootstrapped");

        if (!joinRing)
            throw new ConfigurationException("Cannot set both join_ring=false and attempt to replace a node");

        if (!shouldBootstrap() && !ALLOW_UNSAFE_REPLACE.getBoolean())
            throw new RuntimeException("Replacing a node without bootstrapping risks invalidating consistency " +
                                       "guarantees as the expected data may not be present until repair is run. " +
                                       "To perform this operation, please restart with " +
                                       "-D" + ALLOW_UNSAFE_REPLACE.getKey() + "=true");

        InetAddressAndPort replaceAddress = DatabaseDescriptor.getReplaceAddress();
        logger.info("Gathering node replacement information for {}", replaceAddress);
        Map<InetAddressAndPort, EndpointState> epStates = Gossiper.instance.doShadowRound();
        // as we've completed the shadow round of gossip, we should be able to find the node we're replacing
        EndpointState state = epStates.get(replaceAddress);
        if (state == null)
            throw new RuntimeException(String.format("Cannot replace_address %s because it doesn't exist in gossip", replaceAddress));

        validateEndpointSnitch(epStates.values().iterator());

        try
        {
            VersionedValue tokensVersionedValue = state.getApplicationState(ApplicationState.TOKENS);
            if (tokensVersionedValue == null)
                throw new RuntimeException(String.format("Could not find tokens for %s to replace", replaceAddress));

            Collection<Token> tokens = TokenSerializer.deserialize(tokenMetadata.partitioner, new DataInputStream(new ByteArrayInputStream(tokensVersionedValue.toBytes())));
            bootstrapTokens = validateReplacementBootstrapTokens(tokenMetadata, replaceAddress, tokens);

            if (state.isEmptyWithoutStatus() && REPLACEMENT_ALLOW_EMPTY.getBoolean())
            {
                logger.warn("Gossip state not present for replacing node {}. Adding temporary entry to continue.", replaceAddress);

                // When replacing a node, we take ownership of all its tokens.
                // If that node is currently down and not present in the gossip info
                // of any other live peers, then we will not be able to take ownership
                // of its tokens during bootstrap as they have no way of being propagated
                // to this node's TokenMetadata. TM is loaded at startup (in which case
                // it will be/ empty for a new replacement node) and only updated with
                // tokens for an endpoint during normal state propagation (which will not
                // occur if no peers have gossip state for it).
                // However, the presence of host id and tokens in the system tables implies
                // that the node managed to complete bootstrap at some point in the past.
                // Peers may include this information loaded directly from system tables
                // in a GossipDigestAck *only if* the GossipDigestSyn was sent as part of a
                // shadow round (otherwise, a GossipDigestAck contains only state about peers
                // learned via gossip).
                // It is safe to do this here as since we completed a shadow round we know
                // that :
                // * replaceAddress successfully bootstrapped at some point and owned these
                //   tokens
                // * we know that no other node currently owns these tokens
                // * we are going to completely take over replaceAddress's ownership of
                //   these tokens.
                tokenMetadata.updateNormalTokens(bootstrapTokens, replaceAddress);
                UUID hostId = Gossiper.instance.getHostId(replaceAddress, epStates);
                if (hostId != null)
                    tokenMetadata.updateHostId(hostId, replaceAddress);

                // If we were only able to learn about the node being replaced through the
                // shadow gossip round (i.e. there is no state in gossip across the cluster
                // about it, perhaps because the entire cluster has been bounced since it went
                // down), then we're safe to proceed with the replacement. In this case, there
                // will be no local endpoint state as we discard the results of the shadow
                // round after preparing replacement info. We inject a minimal EndpointState
                // to keep FailureDetector::isAlive and Gossiper::compareEndpointStartup from
                // failing later in the replacement, as they both expect the replaced node to
                // be fully present in gossip.
                // Otherwise, if the replaced node is present in gossip, we need check that
                // it is not in fact live.
                // We choose to not include the EndpointState provided during the shadow round
                // as its possible to include more state than is desired, so by creating a
                // new empty endpoint without that information we can control what is in our
                // local gossip state
                Gossiper.instance.initializeUnreachableNodeUnsafe(replaceAddress);
            }
        }
        catch (IOException e)
        {
            throw new RuntimeException(e);
        }

        UUID localHostId = SystemKeyspace.getOrInitializeLocalHostId();

        if (isReplacingSameAddress())
        {
            localHostId = Gossiper.instance.getHostId(replaceAddress, epStates);
            SystemKeyspace.setLocalHostId(localHostId); // use the replacee's host Id as our own so we receive hints, etc
        }

        return localHostId;
    }

    private static Collection<Token> validateReplacementBootstrapTokens(TokenMetadata tokenMetadata,
                                                                        InetAddressAndPort replaceAddress,
                                                                        Collection<Token> bootstrapTokens)
    {
        Map<Token, InetAddressAndPort> conflicts = new HashMap<>();
        for (Token token : bootstrapTokens)
        {
            InetAddressAndPort conflict = tokenMetadata.getEndpoint(token);
            if (null != conflict && !conflict.equals(replaceAddress))
                conflicts.put(token, tokenMetadata.getEndpoint(token));
        }

        if (!conflicts.isEmpty())
        {
            String error = String.format("Conflicting token ownership information detected between " +
                                         "gossip and current ring view during proposed replacement " +
                                         "of %s. Some tokens identified in gossip for the node being " +
                                         "replaced are currently owned by other peers: %s",
                                         replaceAddress,
                                         conflicts.entrySet()
                                                  .stream()
                                                  .map(e -> e.getKey() + "(" + e.getValue() + ")" )
                                                  .collect(Collectors.joining(",")));
            throw new RuntimeException(error);

        }
        return bootstrapTokens;
    }

    public synchronized void checkForEndpointCollision(UUID localHostId, Set<InetAddressAndPort> peers) throws ConfigurationException
    {
        if (ALLOW_UNSAFE_JOIN.getBoolean())
        {
            logger.warn("Skipping endpoint collision check as " + ALLOW_UNSAFE_JOIN.getKey() + "=true");
            return;
        }

        logger.debug("Starting shadow gossip round to check for endpoint collision");
        Map<InetAddressAndPort, EndpointState> epStates = Gossiper.instance.doShadowRound(peers);

        if (epStates.isEmpty() && DatabaseDescriptor.getSeeds().contains(FBUtilities.getBroadcastAddressAndPort()))
            logger.info("Unable to gossip with any peers but continuing anyway since node is in its own seed list");

        // If bootstrapping, check whether any previously known status for the endpoint makes it unsafe to do so.
        // If not bootstrapping, compare the host id for this endpoint learned from gossip (if any) with the local
        // one, which was either read from system.local or generated at startup. If a learned id is present &
        // doesn't match the local, then the node needs replacing
        if (!Gossiper.instance.isSafeForStartup(FBUtilities.getBroadcastAddressAndPort(), localHostId, shouldBootstrap(), epStates))
        {
            throw new RuntimeException(String.format("A node with address %s already exists, cancelling join. " +
                                                     "Use %s if you want to replace this node.",
                                                     FBUtilities.getBroadcastAddressAndPort(), REPLACE_ADDRESS.getKey()));
        }

        validateEndpointSnitch(epStates.values().iterator());

        if (shouldBootstrap() && useStrictConsistency && !allowSimultaneousMoves())
        {
            for (Map.Entry<InetAddressAndPort, EndpointState> entry : epStates.entrySet())
            {
                // ignore local node or empty status
                if (entry.getKey().equals(FBUtilities.getBroadcastAddressAndPort()) || (entry.getValue().getApplicationState(ApplicationState.STATUS_WITH_PORT) == null & entry.getValue().getApplicationState(ApplicationState.STATUS) == null))
                    continue;

                VersionedValue value = entry.getValue().getApplicationState(ApplicationState.STATUS_WITH_PORT);
                if (value == null)
                {
                    value = entry.getValue().getApplicationState(ApplicationState.STATUS);
                }

                String[] pieces = splitValue(value);
                assert (pieces.length > 0);
                String state = pieces[0];
                if (state.equals(VersionedValue.STATUS_BOOTSTRAPPING) || state.equals(VersionedValue.STATUS_LEAVING) || state.equals(VersionedValue.STATUS_MOVING))
                    throw new UnsupportedOperationException("Other bootstrapping/leaving/moving nodes detected, cannot bootstrap while " + CONSISTENT_RANGE_MOVEMENT.getKey() + " is true");
            }
        }
    }

    private static void validateEndpointSnitch(Iterator<EndpointState> endpointStates)
    {
        Set<String> datacenters = new HashSet<>();
        Set<String> racks = new HashSet<>();
        while (endpointStates.hasNext())
        {
            EndpointState state = endpointStates.next();
            VersionedValue val = state.getApplicationState(ApplicationState.DC);
            if (val != null)
                datacenters.add(val.value);
            val = state.getApplicationState(ApplicationState.RACK);
            if (val != null)
                racks.add(val.value);
        }

        IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
        if (!snitch.validate(datacenters, racks))
        {
            throw new IllegalStateException();
        }
    }

    private boolean allowSimultaneousMoves()
    {
        return allowSimultaneousMoves && DatabaseDescriptor.getNumTokens() == 1;
    }

    // for testing only
    public void unsafeInitialize() throws ConfigurationException
    {
        initialized = true;
        gossipActive = true;
        Gossiper.instance.register(this);
        Gossiper.instance.start((int) (currentTimeMillis() / 1000)); // needed for node-ring gathering.
        Gossiper.instance.addLocalApplicationState(ApplicationState.NET_VERSION, valueFactory.networkVersion());
        MessagingService.instance().listen();
    }

    public synchronized void initServer() throws ConfigurationException
    {
        initServer(SCHEMA_DELAY_MILLIS, RING_DELAY_MILLIS);
    }

    public synchronized void initServer(int schemaAndRingDelayMillis) throws ConfigurationException
    {
        initServer(schemaAndRingDelayMillis, RING_DELAY_MILLIS);
    }

    public synchronized void initServer(int schemaTimeoutMillis, int ringTimeoutMillis) throws ConfigurationException
    {
        logger.info("Cassandra version: {}", FBUtilities.getReleaseVersionString());
        logger.info("Git SHA: {}", FBUtilities.getGitSHA());
        logger.info("CQL version: {}", QueryProcessor.CQL_VERSION);
        logger.info("Native protocol supported versions: {} (default: {})",
                    StringUtils.join(ProtocolVersion.supportedVersions(), ", "), ProtocolVersion.CURRENT);

        try
        {
            // Ensure StorageProxy is initialized on start-up; see CASSANDRA-3797.
            Class.forName("org.apache.cassandra.service.StorageProxy");
            // also IndexSummaryManager, which is otherwise unreferenced
            Class.forName("org.apache.cassandra.io.sstable.indexsummary.IndexSummaryManager");
        }
        catch (ClassNotFoundException e)
        {
            throw new AssertionError(e);
        }

        if (LOAD_RING_STATE.getBoolean())
        {
            logger.info("Loading persisted ring state");
            populatePeerTokenMetadata();
            for (InetAddressAndPort endpoint : tokenMetadata.getAllEndpoints())
                Gossiper.runInGossipStageBlocking(() -> Gossiper.instance.addSavedEndpoint(endpoint));
        }

        // daemon threads, like our executors', continue to run while shutdown hooks are invoked
        drainOnShutdown = NamedThreadFactory.createThread(new WrappedRunnable()
        {
            @Override
            public void runMayThrow() throws InterruptedException, ExecutionException, IOException
            {
                drain(true);
                try
                {
                    ExecutorUtils.shutdownNowAndWait(1, MINUTES, ScheduledExecutors.scheduledFastTasks);
                }
                catch (Throwable t)
                {
                    logger.warn("Unable to terminate fast tasks within 1 minute.", t);
                }
                finally
                {
                    LoggingSupportFactory.getLoggingSupport().onShutdown();
                }
            }
        }, "StorageServiceShutdownHook");
        Runtime.getRuntime().addShutdownHook(drainOnShutdown);

        replacing = isReplacing();

        if (!START_GOSSIP.getBoolean())
        {
            logger.info("Not starting gossip as requested.");
            completeInitialization();
            return;
        }

        prepareToJoin();

        // Has to be called after the host id has potentially changed in prepareToJoin().
        try
        {
            CacheService.instance.counterCache.loadSavedAsync().get();
        }
        catch (Throwable t)
        {
            JVMStabilityInspector.inspectThrowable(t);
            logger.warn("Error loading counter cache", t);
        }

        if (joinRing)
        {
            joinTokenRing(schemaTimeoutMillis, ringTimeoutMillis);
        }
        else
        {
            Collection<Token> tokens = SystemKeyspace.getSavedTokens();
            if (!tokens.isEmpty())
            {
                tokenMetadata.updateNormalTokens(tokens, FBUtilities.getBroadcastAddressAndPort());
                // order is important here, the gossiper can fire in between adding these two states.  It's ok to send TOKENS without STATUS, but *not* vice versa.
                List<Pair<ApplicationState, VersionedValue>> states = new ArrayList<Pair<ApplicationState, VersionedValue>>();
                states.add(Pair.create(ApplicationState.TOKENS, valueFactory.tokens(tokens)));
                states.add(Pair.create(ApplicationState.STATUS_WITH_PORT, valueFactory.hibernate(true)));
                states.add(Pair.create(ApplicationState.STATUS, valueFactory.hibernate(true)));
                Gossiper.instance.addLocalApplicationStates(states);
            }
            doAuthSetup(true);
            logger.info("Not joining ring as requested. Use JMX (StorageService->joinRing()) to initiate ring joining");
        }

        completeInitialization();
    }

    @VisibleForTesting
    public void completeInitialization()
    {
        if (!initialized)
            registerMBeans();
        initialized = true;
    }

    public void populateTokenMetadata()
    {
        if (LOAD_RING_STATE.getBoolean())
        {
            populatePeerTokenMetadata();
            // if we have not completed bootstrapping, we should not add ourselves as a normal token
            if (!shouldBootstrap())
                tokenMetadata.updateNormalTokens(SystemKeyspace.getSavedTokens(), FBUtilities.getBroadcastAddressAndPort());

            logger.info("Token metadata: {}", tokenMetadata);
        }
    }

    private void populatePeerTokenMetadata()
    {
        logger.info("Populating token metadata from system tables");
        Multimap<InetAddressAndPort, Token> loadedTokens = SystemKeyspace.loadTokens();

        // entry has been mistakenly added, delete it
        if (loadedTokens.containsKey(FBUtilities.getBroadcastAddressAndPort()))
            SystemKeyspace.removeEndpoint(FBUtilities.getBroadcastAddressAndPort());

        Map<InetAddressAndPort, UUID> loadedHostIds = SystemKeyspace.loadHostIds();
        Map<UUID, InetAddressAndPort> hostIdToEndpointMap = new HashMap<>();
        for (InetAddressAndPort ep : loadedTokens.keySet())
        {
            UUID hostId = loadedHostIds.get(ep);
            if (hostId != null)
                hostIdToEndpointMap.put(hostId, ep);
        }
        tokenMetadata.updateNormalTokens(loadedTokens);
        tokenMetadata.updateHostIds(hostIdToEndpointMap);
    }

    public boolean isReplacing()
    {
        if (replacing)
            return true;

        if (REPLACE_ADDRESS_FIRST_BOOT.getString() != null && SystemKeyspace.bootstrapComplete())
        {
            logger.info("Replace address on the first boot requested; this node is already bootstrapped");
            return false;
        }

        return DatabaseDescriptor.getReplaceAddress() != null;
    }

    /**
     * In the event of forceful termination we need to remove the shutdown hook to prevent hanging (OOM for instance)
     */
    public void removeShutdownHook()
    {
        PathUtils.clearOnExitThreads();

        if (drainOnShutdown != null)
            Runtime.getRuntime().removeShutdownHook(drainOnShutdown);
    }

    private boolean shouldBootstrap()
    {
        return DatabaseDescriptor.isAutoBootstrap() && !SystemKeyspace.bootstrapComplete() && !isSeed();
    }

    public static boolean isSeed()
    {
        return DatabaseDescriptor.getSeeds().contains(FBUtilities.getBroadcastAddressAndPort());
    }

    private void prepareToJoin() throws ConfigurationException
    {
        if (!joined)
        {
            Map<ApplicationState, VersionedValue> appStates = new EnumMap<>(ApplicationState.class);

            if (SystemKeyspace.wasDecommissioned())
            {
                if (OVERRIDE_DECOMMISSION.getBoolean())
                {
                    logger.warn("This node was decommissioned, but overriding by operator request.");
                    SystemKeyspace.setBootstrapState(SystemKeyspace.BootstrapState.COMPLETED);
                }
                else
                {
                    throw new ConfigurationException("This node was decommissioned and will not rejoin the ring unless -D" + OVERRIDE_DECOMMISSION.getKey() +
                                                     "=true has been set, or all existing data is removed and the node is bootstrapped again");
                }
            }

            if (DatabaseDescriptor.getReplaceTokens().size() > 0 || DatabaseDescriptor.getReplaceNode() != null)
                throw new RuntimeException("Replace method removed; use " + REPLACE_ADDRESS.getKey() + " system property instead.");

            MessagingService.instance().listen();

            UUID localHostId = SystemKeyspace.getOrInitializeLocalHostId();

            if (replacing)
            {
                localHostId = prepareForReplacement();
                appStates.put(ApplicationState.TOKENS, valueFactory.tokens(bootstrapTokens));

                if (!shouldBootstrap())
                {
                    // Will not do replace procedure, persist the tokens we're taking over locally
                    // so that they don't get clobbered with auto generated ones in joinTokenRing
                    SystemKeyspace.updateTokens(bootstrapTokens);
                }
                else if (isReplacingSameAddress())
                {
                    //only go into hibernate state if replacing the same address (CASSANDRA-8523)
                    logger.warn("Writes will not be forwarded to this node during replacement because it has the same address as " +
                                "the node to be replaced ({}). If the previous node has been down for longer than max_hint_window, " +
                                "repair must be run after the replacement process in order to make this node consistent.",
                                DatabaseDescriptor.getReplaceAddress());
                    appStates.put(ApplicationState.STATUS_WITH_PORT, valueFactory.hibernate(true));
                    appStates.put(ApplicationState.STATUS, valueFactory.hibernate(true));
                }
            }
            else
            {
                checkForEndpointCollision(localHostId, SystemKeyspace.loadHostIds().keySet());
                if (SystemKeyspace.bootstrapComplete())
                {
                    Preconditions.checkState(!Config.isClientMode());
                    // tokens are only ever saved to system.local after bootstrap has completed and we're joining the ring,
                    // or when token update operations (move, decom) are completed
                    Collection<Token> savedTokens = SystemKeyspace.getSavedTokens();
                    if (!savedTokens.isEmpty())
                        appStates.put(ApplicationState.TOKENS, valueFactory.tokens(savedTokens));
                }
            }

            // have to start the gossip service before we can see any info on other nodes.  this is necessary
            // for bootstrap to get the load info it needs.
            // (we won't be part of the storage ring though until we add a counterId to our state, below.)
            // Seed the host ID-to-endpoint map with our own ID.
            getTokenMetadata().updateHostId(localHostId, FBUtilities.getBroadcastAddressAndPort());
            appStates.put(ApplicationState.NET_VERSION, valueFactory.networkVersion());
            appStates.put(ApplicationState.HOST_ID, valueFactory.hostId(localHostId));
            appStates.put(ApplicationState.NATIVE_ADDRESS_AND_PORT, valueFactory.nativeaddressAndPort(FBUtilities.getBroadcastNativeAddressAndPort()));
            appStates.put(ApplicationState.RPC_ADDRESS, valueFactory.rpcaddress(FBUtilities.getJustBroadcastNativeAddress()));
            appStates.put(ApplicationState.RELEASE_VERSION, valueFactory.releaseVersion());
            appStates.put(ApplicationState.SSTABLE_VERSIONS, valueFactory.sstableVersions(sstablesTracker.versionsInUse()));

            logger.info("Starting up server gossip");
            Gossiper.instance.register(this);
            Gossiper.instance.start(SystemKeyspace.incrementAndGetGeneration(), appStates); // needed for node-ring gathering.
            gossipActive = true;

            sstablesTracker.register((notification, o) -> {
                if (!(notification instanceof SSTablesVersionsInUseChangeNotification))
                    return;

                Set<Version> versions = ((SSTablesVersionsInUseChangeNotification)notification).versionsInUse;
                logger.debug("Updating local sstables version in Gossip to {}", versions);

                Gossiper.instance.addLocalApplicationState(ApplicationState.SSTABLE_VERSIONS,
                                                           valueFactory.sstableVersions(versions));
            });

            // gossip snitch infos (local DC and rack)
            gossipSnitchInfo();
            Schema.instance.startSync();
            LoadBroadcaster.instance.startBroadcasting();
            DiskUsageBroadcaster.instance.startBroadcasting();
            HintsService.instance.startDispatch();
            BatchlogManager.instance.start();
            startSnapshotManager();
        }
    }

    @VisibleForTesting
    public void startSnapshotManager()
    {
        snapshotManager.start();
    }

    public void waitForSchema(long schemaTimeoutMillis, long ringTimeoutMillis)
    {
        Instant deadline = FBUtilities.now().plus(java.time.Duration.ofMillis(ringTimeoutMillis));

        while (Schema.instance.isEmpty() && FBUtilities.now().isBefore(deadline))
            Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);

        if (!Schema.instance.waitUntilReady(java.time.Duration.ofMillis(schemaTimeoutMillis)))
            throw new IllegalStateException("Could not achieve schema readiness in " + java.time.Duration.ofMillis(schemaTimeoutMillis));
    }

    private void joinTokenRing(long schemaTimeoutMillis, long ringTimeoutMillis) throws ConfigurationException
    {
        joinTokenRing(!isSurveyMode, shouldBootstrap(), schemaTimeoutMillis, INDEFINITE, ringTimeoutMillis);
    }

    @VisibleForTesting
    public void joinTokenRing(boolean finishJoiningRing,
                              boolean shouldBootstrap,
                              long schemaTimeoutMillis,
                              long bootstrapTimeoutMillis,
                              long ringTimeoutMillis) throws ConfigurationException
    {
        joined = true;

        // We bootstrap if we haven't successfully bootstrapped before, as long as we are not a seed.
        // If we are a seed, or if the user manually sets auto_bootstrap to false,
        // we'll skip streaming data from other nodes and jump directly into the ring.
        //
        // The seed check allows us to skip the RING_DELAY sleep for the single-node cluster case,
        // which is useful for both new users and testing.
        //
        // We attempted to replace this with a schema-presence check, but you need a meaningful sleep
        // to get schema info from gossip which defeats the purpose.  See CASSANDRA-4427 for the gory details.
        Set<InetAddressAndPort> current = new HashSet<>();
        if (logger.isDebugEnabled())
        {
            logger.debug("Bootstrap variables: {} {} {} {}",
                         DatabaseDescriptor.isAutoBootstrap(),
                         SystemKeyspace.bootstrapInProgress(),
                         SystemKeyspace.bootstrapComplete(),
                         DatabaseDescriptor.getSeeds().contains(FBUtilities.getBroadcastAddressAndPort()));
        }
        if (DatabaseDescriptor.isAutoBootstrap() && !SystemKeyspace.bootstrapComplete() && DatabaseDescriptor.getSeeds().contains(FBUtilities.getBroadcastAddressAndPort()))
        {
            logger.info("This node will not auto bootstrap because it is configured to be a seed node.");
        }

        boolean dataAvailable = true; // make this to false when bootstrap streaming failed

        if (shouldBootstrap)
        {
            current.addAll(prepareForBootstrap(schemaTimeoutMillis, ringTimeoutMillis));
            dataAvailable = bootstrap(bootstrapTokens, bootstrapTimeoutMillis);
        }
        else
        {
            bootstrapTokens = SystemKeyspace.getSavedTokens();
            if (bootstrapTokens.isEmpty())
            {
                bootstrapTokens = BootStrapper.getBootstrapTokens(tokenMetadata, FBUtilities.getBroadcastAddressAndPort(), schemaTimeoutMillis, ringTimeoutMillis);
            }
            else
            {
                if (bootstrapTokens.size() != DatabaseDescriptor.getNumTokens())
                    throw new ConfigurationException("Cannot change the number of tokens from " + bootstrapTokens.size() + " to " + DatabaseDescriptor.getNumTokens());
                else
                    logger.info("Using saved tokens {}", bootstrapTokens);
            }
        }

        setUpDistributedSystemKeyspaces();

        if (finishJoiningRing)
        {
            if (dataAvailable)
            {
                finishJoiningRing(shouldBootstrap, bootstrapTokens);
                // remove the existing info about the replaced node.
                if (!current.isEmpty())
                {
                    Gossiper.runInGossipStageBlocking(() -> {
                        for (InetAddressAndPort existing : current)
                            Gossiper.instance.replacedEndpoint(existing);
                    });
                }
            }
            else
            {
                logger.warn("Some data streaming failed. Use nodetool to check bootstrap state and resume. For more, see `nodetool help bootstrap`. {}", SystemKeyspace.getBootstrapState());
            }

            StorageProxy.instance.initialLoadPartitionDenylist();
        }
        else
        {
            if (dataAvailable)
                logger.info("Startup complete, but write survey mode is active, not becoming an active ring member. Use JMX (StorageService->joinRing()) to finalize ring joining.");
            else
                logger.warn("Some data streaming failed. Use nodetool to check bootstrap state and resume. For more, see `nodetool help bootstrap`. {}", SystemKeyspace.getBootstrapState());
        }
    }

    public static boolean isReplacingSameAddress()
    {
        InetAddressAndPort replaceAddress = DatabaseDescriptor.getReplaceAddress();
        return replaceAddress != null && replaceAddress.equals(FBUtilities.getBroadcastAddressAndPort());
    }

    public void gossipSnitchInfo()
    {
        IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
        String dc = snitch.getLocalDatacenter();
        String rack = snitch.getLocalRack();
        Gossiper.instance.addLocalApplicationState(ApplicationState.DC, StorageService.instance.valueFactory.datacenter(dc));
        Gossiper.instance.addLocalApplicationState(ApplicationState.RACK, StorageService.instance.valueFactory.rack(rack));
    }

    public void joinRing() throws IOException
    {
        SystemKeyspace.BootstrapState state = SystemKeyspace.getBootstrapState();
        joinRing(state.equals(SystemKeyspace.BootstrapState.IN_PROGRESS));
    }

    private synchronized void joinRing(boolean resumedBootstrap) throws IOException
    {
        if (!joined)
        {
            logger.info("Joining ring by operator request");
            try
            {
                joinTokenRing(SCHEMA_DELAY_MILLIS, 0);
                doAuthSetup(false);
            }
            catch (ConfigurationException e)
            {
                throw new IOException(e.getMessage());
            }
        }
        else if (isSurveyMode)
        {
            // if isSurveyMode is on then verify isBootstrapMode
            // node can join the ring even if isBootstrapMode is true which should not happen
            if (!isBootstrapMode())
            {
                logger.info("Leaving write survey mode and joining ring at operator request");
                finishJoiningRing(resumedBootstrap, SystemKeyspace.getSavedTokens());
                doAuthSetup(false);
                isSurveyMode = false;
                daemon.start();
            }
            else
            {
                logger.warn("Can't join the ring because in write_survey mode and bootstrap hasn't completed");
            }
        }
        else if (isBootstrapMode())
        {
            // bootstrap is not complete hence node cannot join the ring
            logger.warn("Can't join the ring because bootstrap hasn't completed.");
        }
    }

    private void executePreJoinTasks(boolean bootstrap)
    {
        StreamSupport.stream(ColumnFamilyStore.all().spliterator(), false)
                .filter(cfs -> Schema.instance.getUserKeyspaces().names().contains(cfs.keyspace.getName()))
                .forEach(cfs -> cfs.indexManager.executePreJoinTasksBlocking(bootstrap));
    }

    @VisibleForTesting
    public void finishJoiningRing(boolean didBootstrap, Collection<Token> tokens)
    {
        // start participating in the ring.
        setMode(Mode.JOINING, "Finish joining ring", true);
        SystemKeyspace.setBootstrapState(SystemKeyspace.BootstrapState.COMPLETED);
        executePreJoinTasks(didBootstrap);
        setTokens(tokens);

        assert tokenMetadata.sortedTokens().size() > 0;
    }

    @VisibleForTesting
    public void doAuthSetup(boolean setUpSchema)
    {
        if (!authSetupCalled.getAndSet(true))
        {
            if (setUpSchema)
            {
                Schema.instance.transform(SchemaTransformations.updateSystemKeyspace(AuthKeyspace.metadata(), AuthKeyspace.GENERATION));
            }

            DatabaseDescriptor.getRoleManager().setup();
            DatabaseDescriptor.getAuthenticator().setup();
            DatabaseDescriptor.getInternodeAuthenticator().setupInternode();
            DatabaseDescriptor.getAuthorizer().setup();
            DatabaseDescriptor.getNetworkAuthorizer().setup();
            AuthCacheService.initializeAndRegisterCaches();
            Schema.instance.registerListener(new AuthSchemaChangeListener());
            authSetupComplete = true;
        }
    }

    public boolean isAuthSetupComplete()
    {
        return authSetupComplete;
    }

    @VisibleForTesting
    public boolean authSetupCalled()
    {
        return authSetupCalled.get();
    }


    @VisibleForTesting
    public void setUpDistributedSystemKeyspaces()
    {
        Schema.instance.transform(SchemaTransformations.updateSystemKeyspace(TraceKeyspace.metadata(), TraceKeyspace.GENERATION));
        Schema.instance.transform(SchemaTransformations.updateSystemKeyspace(SystemDistributedKeyspace.metadata(), SystemDistributedKeyspace.GENERATION));
        Schema.instance.transform(SchemaTransformations.updateSystemKeyspace(AuthKeyspace.metadata(), AuthKeyspace.GENERATION));
    }

    public boolean isJoined()
    {
        return tokenMetadata.isMember(FBUtilities.getBroadcastAddressAndPort()) && !isSurveyMode;
    }

    public void rebuild(String sourceDc)
    {
        rebuild(sourceDc, null, null, null, false);
    }

    public void rebuild(String sourceDc, String keyspace, String tokens, String specificSources)
    {
        rebuild(sourceDc, keyspace, tokens, specificSources, false);
    }

    public void rebuild(String sourceDc, String keyspace, String tokens, String specificSources, boolean excludeLocalDatacenterNodes)
    {
        try
        {
            // check ongoing rebuild
            if (!isRebuilding.compareAndSet(false, true))
            {
                throw new IllegalStateException("Node is still rebuilding. Check nodetool netstats.");
            }

            // fail if source DC is local and --exclude-local-dc is set
            if (sourceDc != null && sourceDc.equals(DatabaseDescriptor.getLocalDataCenter()) && excludeLocalDatacenterNodes)
            {
                throw new IllegalArgumentException("Cannot set source data center to be local data center, when excludeLocalDataCenter flag is set");
            }

            if (sourceDc != null)
            {
                TokenMetadata.Topology topology = getTokenMetadata().cloneOnlyTokenMap().getTopology();
                Set<String> availableDCs = topology.getDatacenterEndpoints().keySet();
                if (!availableDCs.contains(sourceDc))
                {
                    throw new IllegalArgumentException(String.format("Provided datacenter '%s' is not a valid datacenter, available datacenters are: %s",
                                                                     sourceDc, String.join(",", availableDCs)));
                }
            }
        }
        catch (Throwable ex)
        {
            isRebuilding.set(false);
            throw ex;
        }

        try
        {
            // check the arguments
            if (keyspace == null && tokens != null)
            {
                throw new IllegalArgumentException("Cannot specify tokens without keyspace.");
            }

            logger.info("rebuild from dc: {}, {}, {}", sourceDc == null ? "(any dc)" : sourceDc,
                        keyspace == null ? "(All keyspaces)" : keyspace,
                        tokens == null ? "(All tokens)" : tokens);

            repairPaxosForTopologyChange("rebuild");

            RangeStreamer streamer = new RangeStreamer(tokenMetadata,
                                                       null,
                                                       FBUtilities.getBroadcastAddressAndPort(),
                                                       StreamOperation.REBUILD,
                                                       useStrictConsistency && !replacing,
                                                       DatabaseDescriptor.getEndpointSnitch(),
                                                       streamStateStore,
                                                       false,
                                                       DatabaseDescriptor.getStreamingConnectionsPerHost());
            if (sourceDc != null)
                streamer.addSourceFilter(new RangeStreamer.SingleDatacenterFilter(DatabaseDescriptor.getEndpointSnitch(), sourceDc));

            if (excludeLocalDatacenterNodes)
                streamer.addSourceFilter(new RangeStreamer.ExcludeLocalDatacenterFilter(DatabaseDescriptor.getEndpointSnitch()));

            if (keyspace == null)
            {
                for (String keyspaceName : Schema.instance.getNonLocalStrategyKeyspaces().names())
                    streamer.addRanges(keyspaceName, getLocalReplicas(keyspaceName));
            }
            else if (tokens == null)
            {
                streamer.addRanges(keyspace, getLocalReplicas(keyspace));
            }
            else
            {
                Token.TokenFactory factory = getTokenFactory();
                List<Range<Token>> ranges = new ArrayList<>();
                Pattern rangePattern = Pattern.compile("\\(\\s*(-?\\w+)\\s*,\\s*(-?\\w+)\\s*\\]");
                try (Scanner tokenScanner = new Scanner(tokens))
                {
                    while (tokenScanner.findInLine(rangePattern) != null)
                    {
                        MatchResult range = tokenScanner.match();
                        Token startToken = factory.fromString(range.group(1));
                        Token endToken = factory.fromString(range.group(2));
                        logger.info("adding range: ({},{}]", startToken, endToken);
                        ranges.add(new Range<>(startToken, endToken));
                    }
                    if (tokenScanner.hasNext())
                        throw new IllegalArgumentException("Unexpected string: " + tokenScanner.next());
                }

                // Ensure all specified ranges are actually ranges owned by this host
                RangesAtEndpoint localReplicas = getLocalReplicas(keyspace);
                RangesAtEndpoint.Builder streamRanges = new RangesAtEndpoint.Builder(FBUtilities.getBroadcastAddressAndPort(), ranges.size());
                for (Range<Token> specifiedRange : ranges)
                {
                    boolean foundParentRange = false;
                    for (Replica localReplica : localReplicas)
                    {
                        if (localReplica.contains(specifiedRange))
                        {
                            streamRanges.add(localReplica.decorateSubrange(specifiedRange));
                            foundParentRange = true;
                            break;
                        }
                    }
                    if (!foundParentRange)
                    {
                        throw new IllegalArgumentException(String.format("The specified range %s is not a range that is owned by this node. Please ensure that all token ranges specified to be rebuilt belong to this node.", specifiedRange.toString()));
                    }
                }

                if (specificSources != null)
                {
                    String[] stringHosts = specificSources.split(",");
                    Set<InetAddressAndPort> sources = new HashSet<>(stringHosts.length);
                    for (String stringHost : stringHosts)
                    {
                        try
                        {
                            InetAddressAndPort endpoint = InetAddressAndPort.getByName(stringHost);
                            if (FBUtilities.getBroadcastAddressAndPort().equals(endpoint))
                            {
                                throw new IllegalArgumentException("This host was specified as a source for rebuilding. Sources for a rebuild can only be other nodes in the cluster.");
                            }
                            sources.add(endpoint);
                        }
                        catch (UnknownHostException ex)
                        {
                            throw new IllegalArgumentException("Unknown host specified " + stringHost, ex);
                        }
                    }
                    streamer.addSourceFilter(new RangeStreamer.AllowedSourcesFilter(sources));
                }

                streamer.addRanges(keyspace, streamRanges.build());
            }

            StreamResultFuture resultFuture = streamer.fetchAsync();
            // wait for result
            resultFuture.get();
        }
        catch (InterruptedException e)
        {
            throw new UncheckedInterruptedException(e);
        }
        catch (ExecutionException e)
        {
            // This is used exclusively through JMX, so log the full trace but only throw a simple RTE
            logger.error("Error while rebuilding node", e.getCause());
            throw new RuntimeException("Error while rebuilding node: " + e.getCause().getMessage());
        }
        finally
        {
            // rebuild is done (successfully or not)
            isRebuilding.set(false);
        }
    }

    public void setRpcTimeout(long value)
    {
        DatabaseDescriptor.setRpcTimeout(value);
        logger.info("set rpc timeout to {} ms", value);
    }

    public long getRpcTimeout()
    {
        return DatabaseDescriptor.getRpcTimeout(MILLISECONDS);
    }

    public void setReadRpcTimeout(long value)
    {
        DatabaseDescriptor.setReadRpcTimeout(value);
        logger.info("set read rpc timeout to {} ms", value);
    }

    public long getReadRpcTimeout()
    {
        return DatabaseDescriptor.getReadRpcTimeout(MILLISECONDS);
    }

    public void setRangeRpcTimeout(long value)
    {
        DatabaseDescriptor.setRangeRpcTimeout(value);
        logger.info("set range rpc timeout to {} ms", value);
    }

    public long getRangeRpcTimeout()
    {
        return DatabaseDescriptor.getRangeRpcTimeout(MILLISECONDS);
    }

    public void setWriteRpcTimeout(long value)
    {
        DatabaseDescriptor.setWriteRpcTimeout(value);
        logger.info("set write rpc timeout to {} ms", value);
    }

    public long getWriteRpcTimeout()
    {
        return DatabaseDescriptor.getWriteRpcTimeout(MILLISECONDS);
    }

    public void setInternodeTcpConnectTimeoutInMS(int value)
    {
        DatabaseDescriptor.setInternodeTcpConnectTimeoutInMS(value);
        logger.info("set internode tcp connect timeout to {} ms", value);
    }

    public int getInternodeTcpConnectTimeoutInMS()
    {
        return DatabaseDescriptor.getInternodeTcpConnectTimeoutInMS();
    }

    public void setInternodeTcpUserTimeoutInMS(int value)
    {
        DatabaseDescriptor.setInternodeTcpUserTimeoutInMS(value);
        logger.info("set internode tcp user timeout to {} ms", value);
    }

    public int getInternodeTcpUserTimeoutInMS()
    {
        return DatabaseDescriptor.getInternodeTcpUserTimeoutInMS();
    }

    public void setInternodeStreamingTcpUserTimeoutInMS(int value)
    {
        Preconditions.checkArgument(value >= 0, "TCP user timeout cannot be negative for internode streaming connection. Got %s", value);
        DatabaseDescriptor.setInternodeStreamingTcpUserTimeoutInMS(value);
        logger.info("set internode streaming tcp user timeout to {} ms", value);
    }

    public int getInternodeStreamingTcpUserTimeoutInMS()
    {
        return DatabaseDescriptor.getInternodeStreamingTcpUserTimeoutInMS();
    }

    public void setCounterWriteRpcTimeout(long value)
    {
        DatabaseDescriptor.setCounterWriteRpcTimeout(value);
        logger.info("set counter write rpc timeout to {} ms", value);
    }

    public long getCounterWriteRpcTimeout()
    {
        return DatabaseDescriptor.getCounterWriteRpcTimeout(MILLISECONDS);
    }

    public void setCasContentionTimeout(long value)
    {
        DatabaseDescriptor.setCasContentionTimeout(value);
        logger.info("set cas contention rpc timeout to {} ms", value);
    }

    public long getCasContentionTimeout()
    {
        return DatabaseDescriptor.getCasContentionTimeout(MILLISECONDS);
    }

    public void setTruncateRpcTimeout(long value)
    {
        DatabaseDescriptor.setTruncateRpcTimeout(value);
        logger.info("set truncate rpc timeout to {} ms", value);
    }

    public long getTruncateRpcTimeout()
    {
        return DatabaseDescriptor.getTruncateRpcTimeout(MILLISECONDS);
    }

    @Deprecated
    public void setStreamThroughputMbPerSec(int value)
    {
        setStreamThroughputMbitPerSec(value);
    }

    public void setStreamThroughputMbitPerSec(int value)
    {
        double oldValue = DatabaseDescriptor.getStreamThroughputOutboundMegabitsPerSecAsDouble();
        DatabaseDescriptor.setStreamThroughputOutboundMegabitsPerSec(value);
        StreamManager.StreamRateLimiter.updateThroughput();
        logger.info("setstreamthroughput: throttle set to {}{} megabits per second (was approximately {} megabits per second)",
                    value, value <= 0 ? " (unlimited)" : "", oldValue);
    }

    public void setStreamThroughputMebibytesPerSec(int value)
    {
        double oldValue = DatabaseDescriptor.getStreamThroughputOutboundMebibytesPerSec();
        DatabaseDescriptor.setStreamThroughputOutboundMebibytesPerSecAsInt(value);
        StreamManager.StreamRateLimiter.updateThroughput();
        logger.info("setstreamthroughput: throttle set to {}{} MiB/s (was {} MiB/s)", value, value <= 0 ? " (unlimited)" : "", oldValue);
    }

    public double getStreamThroughputMebibytesPerSecAsDouble()
    {
        return DatabaseDescriptor.getStreamThroughputOutboundMebibytesPerSec();
    }

    public int getStreamThroughputMebibytesPerSec()
    {
        return DatabaseDescriptor.getStreamThroughputOutboundMebibytesPerSecAsInt();
    }

    @Deprecated
    public int getStreamThroughputMbPerSec()
    {
        return getStreamThroughputMbitPerSec();
    }

    @Deprecated
    public int getStreamThroughputMbitPerSec()
    {
        return DatabaseDescriptor.getStreamThroughputOutboundMegabitsPerSec();
    }

    public double getStreamThroughputMbitPerSecAsDouble()
    {
        return DatabaseDescriptor.getStreamThroughputOutboundMegabitsPerSecAsDouble();
    }

    public void setEntireSSTableStreamThroughputMebibytesPerSec(int value)
    {
        double oldValue = DatabaseDescriptor.getEntireSSTableStreamThroughputOutboundMebibytesPerSec();
        DatabaseDescriptor.setEntireSSTableStreamThroughputOutboundMebibytesPerSec(value);
        StreamManager.StreamRateLimiter.updateEntireSSTableThroughput();
        logger.info("setstreamthroughput (entire SSTable): throttle set to {}{} MiB/s (was {} MiB/s)",
                    value, value <= 0 ? " (unlimited)" : "", oldValue);
    }

    public double getEntireSSTableStreamThroughputMebibytesPerSecAsDouble()
    {
        return DatabaseDescriptor.getEntireSSTableStreamThroughputOutboundMebibytesPerSec();
    }

    @Deprecated
    public void setInterDCStreamThroughputMbPerSec(int value)
    {
        setInterDCStreamThroughputMbitPerSec(value);
    }

    public void setInterDCStreamThroughputMbitPerSec(int value)
    {
        double oldValue = DatabaseDescriptor.getInterDCStreamThroughputOutboundMegabitsPerSecAsDouble();
        DatabaseDescriptor.setInterDCStreamThroughputOutboundMegabitsPerSec(value);
        StreamManager.StreamRateLimiter.updateInterDCThroughput();
        logger.info("setinterdcstreamthroughput: throttle set to {}{} megabits per second (was {} megabits per second)", value, value <= 0 ? " (unlimited)" : "", oldValue);
    }

    @Deprecated
    public int getInterDCStreamThroughputMbPerSec()
    {
        return getInterDCStreamThroughputMbitPerSec();
    }

    @Deprecated
    public int getInterDCStreamThroughputMbitPerSec()
    {
        return DatabaseDescriptor.getInterDCStreamThroughputOutboundMegabitsPerSec();
    }

    public double getInterDCStreamThroughputMbitPerSecAsDouble()
    {
        return DatabaseDescriptor.getInterDCStreamThroughputOutboundMegabitsPerSecAsDouble();
    }

    public void setInterDCStreamThroughputMebibytesPerSec(int value)
    {
        double oldValue = DatabaseDescriptor.getInterDCStreamThroughputOutboundMebibytesPerSec();
        DatabaseDescriptor.setInterDCStreamThroughputOutboundMebibytesPerSecAsInt(value);
        StreamManager.StreamRateLimiter.updateInterDCThroughput();
        logger.info("setinterdcstreamthroughput: throttle set to {}{} MiB/s (was {} MiB/s)", value, value <= 0 ? " (unlimited)" : "", oldValue);
    }

    public int getInterDCStreamThroughputMebibytesPerSec()
    {
        return DatabaseDescriptor.getInterDCStreamThroughputOutboundMebibytesPerSecAsInt();
    }

    public double getInterDCStreamThroughputMebibytesPerSecAsDouble()
    {
        return DatabaseDescriptor.getInterDCStreamThroughputOutboundMebibytesPerSec();
    }

    public void setEntireSSTableInterDCStreamThroughputMebibytesPerSec(int value)
    {
        double oldValue = DatabaseDescriptor.getEntireSSTableInterDCStreamThroughputOutboundMebibytesPerSec();
        DatabaseDescriptor.setEntireSSTableInterDCStreamThroughputOutboundMebibytesPerSec(value);
        StreamManager.StreamRateLimiter.updateEntireSSTableInterDCThroughput();
        logger.info("setinterdcstreamthroughput (entire SSTable): throttle set to {}{} MiB/s (was {} MiB/s)", value, value <= 0 ? " (unlimited)" : "", oldValue);
    }

    public double getEntireSSTableInterDCStreamThroughputMebibytesPerSecAsDouble()
    {
        return DatabaseDescriptor.getEntireSSTableInterDCStreamThroughputOutboundMebibytesPerSec();
    }

    public double getCompactionThroughtputMibPerSecAsDouble()
    {
        return DatabaseDescriptor.getCompactionThroughputMebibytesPerSec();
    }

    public long getCompactionThroughtputBytesPerSec()
    {
        return (long)DatabaseDescriptor.getCompactionThroughputBytesPerSec();
    }

    @Deprecated
    public int getCompactionThroughputMbPerSec()
    {
        return DatabaseDescriptor.getCompactionThroughputMebibytesPerSecAsInt();
    }

    public void setCompactionThroughputMbPerSec(int value)
    {
        double oldValue = DatabaseDescriptor.getCompactionThroughputMebibytesPerSec();
        DatabaseDescriptor.setCompactionThroughputMebibytesPerSec(value);
        double valueInBytes = value * 1024.0 * 1024.0;
        CompactionManager.instance.setRateInBytes(valueInBytes);
        logger.info("compactionthroughput: throttle set to {} mebibytes per second (was {} mebibytes per second)",
                    value, oldValue);
    }

    public int getBatchlogReplayThrottleInKB()
    {
        return DatabaseDescriptor.getBatchlogReplayThrottleInKiB();
    }

    public void setBatchlogReplayThrottleInKB(int throttleInKB)
    {
        DatabaseDescriptor.setBatchlogReplayThrottleInKiB(throttleInKB);
        BatchlogManager.instance.setRate(throttleInKB);
    }

    public int getConcurrentCompactors()
    {
        return DatabaseDescriptor.getConcurrentCompactors();
    }

    public void setConcurrentCompactors(int value)
    {
        if (value <= 0)
            throw new IllegalArgumentException("Number of concurrent compactors should be greater than 0.");
        DatabaseDescriptor.setConcurrentCompactors(value);
        CompactionManager.instance.setConcurrentCompactors(value);
    }

    public void bypassConcurrentValidatorsLimit()
    {
        logger.info("Enabling the ability to set concurrent validations to an unlimited value");
        DatabaseDescriptor.allowUnlimitedConcurrentValidations = true ;
    }

    public void enforceConcurrentValidatorsLimit()
    {
        logger.info("Disabling the ability to set concurrent validations to an unlimited value");
        DatabaseDescriptor.allowUnlimitedConcurrentValidations = false ;
    }

    public boolean isConcurrentValidatorsLimitEnforced()
    {
        return DatabaseDescriptor.allowUnlimitedConcurrentValidations;
    }

    public int getConcurrentValidators()
    {
        return DatabaseDescriptor.getConcurrentValidations();
    }

    public void setConcurrentValidators(int value)
    {
        int concurrentCompactors = DatabaseDescriptor.getConcurrentCompactors();
        if (value > concurrentCompactors && !DatabaseDescriptor.allowUnlimitedConcurrentValidations)
            throw new IllegalArgumentException(
            String.format("Cannot set concurrent_validations greater than concurrent_compactors (%d)",
                          concurrentCompactors));

        if (value <= 0)
        {
            logger.info("Using default value of concurrent_compactors ({}) for concurrent_validations", concurrentCompactors);
            value = concurrentCompactors;
        }
        else
        {
            logger.info("Setting concurrent_validations to {}", value);
        }

        DatabaseDescriptor.setConcurrentValidations(value);
        CompactionManager.instance.setConcurrentValidations();
    }

    public int getConcurrentViewBuilders()
    {
        return DatabaseDescriptor.getConcurrentViewBuilders();
    }

    public void setConcurrentViewBuilders(int value)
    {
        if (value <= 0)
            throw new IllegalArgumentException("Number of concurrent view builders should be greater than 0.");
        DatabaseDescriptor.setConcurrentViewBuilders(value);
        CompactionManager.instance.setConcurrentViewBuilders(DatabaseDescriptor.getConcurrentViewBuilders());
    }

    public boolean isIncrementalBackupsEnabled()
    {
        return DatabaseDescriptor.isIncrementalBackupsEnabled();
    }

    public void setIncrementalBackupsEnabled(boolean value)
    {
        DatabaseDescriptor.setIncrementalBackupsEnabled(value);
    }

    @VisibleForTesting // only used by test
    public void setMovingModeUnsafe()
    {
        setMode(Mode.MOVING, true);
    }

    /**
     * Only used in jvm dtest when not using GOSSIP.
     * See org.apache.cassandra.distributed.impl.Instance#startup(org.apache.cassandra.distributed.api.ICluster)
     */
    @VisibleForTesting
    public void setNormalModeUnsafe()
    {
        setMode(Mode.NORMAL, true);
    }

    private void setMode(Mode m, boolean log)
    {
        setMode(m, null, log);
    }

    private void setMode(Mode m, String msg, boolean log)
    {
        operationMode = m;
        String logMsg = msg == null ? m.toString() : String.format("%s: %s", m, msg);
        if (log)
            logger.info(logMsg);
        else
            logger.debug(logMsg);
    }

    @VisibleForTesting
    public Collection<InetAddressAndPort> prepareForBootstrap(long schemaTimeoutMillis, long ringTimeoutMillis)
    {
        Set<InetAddressAndPort> collisions = new HashSet<>();
        if (SystemKeyspace.bootstrapInProgress())
            logger.warn("Detected previous bootstrap failure; retrying");
        else
            SystemKeyspace.setBootstrapState(SystemKeyspace.BootstrapState.IN_PROGRESS);
        setMode(Mode.JOINING, "waiting for ring information", true);
        waitForSchema(schemaTimeoutMillis, ringTimeoutMillis);
        setMode(Mode.JOINING, "schema complete, ready to bootstrap", true);
        setMode(Mode.JOINING, "waiting for pending range calculation", true);
        PendingRangeCalculatorService.instance.blockUntilFinished();
        setMode(Mode.JOINING, "calculation complete, ready to bootstrap", true);

        logger.debug("... got ring + schema info");

        if (useStrictConsistency && !allowSimultaneousMoves() &&
            (
            tokenMetadata.getBootstrapTokens().valueSet().size() > 0 ||
            tokenMetadata.getSizeOfLeavingEndpoints() > 0 ||
            tokenMetadata.getSizeOfMovingEndpoints() > 0
            ))
        {
            String bootstrapTokens = StringUtils.join(tokenMetadata.getBootstrapTokens().valueSet(), ',');
            String leavingTokens = StringUtils.join(tokenMetadata.getLeavingEndpoints(), ',');
            String movingTokens = StringUtils.join(tokenMetadata.getMovingEndpoints().stream().map(e -> e.right).toArray(), ',');
            throw new UnsupportedOperationException(String.format("Other bootstrapping/leaving/moving nodes detected, cannot bootstrap while %s is true. Nodes detected, bootstrapping: %s; leaving: %s; moving: %s;",
                                                                  CONSISTENT_RANGE_MOVEMENT.getKey(), bootstrapTokens, leavingTokens, movingTokens));
        }

        // get bootstrap tokens
        if (!replacing)
        {
            if (tokenMetadata.isMember(FBUtilities.getBroadcastAddressAndPort()))
            {
                String s = "This node is already a member of the token ring; bootstrap aborted. (If replacing a dead node, remove the old one from the ring first.)";
                throw new UnsupportedOperationException(s);
            }
            setMode(Mode.JOINING, "getting bootstrap token", true);
            bootstrapTokens = BootStrapper.getBootstrapTokens(tokenMetadata, FBUtilities.getBroadcastAddressAndPort(), schemaTimeoutMillis, ringTimeoutMillis);
        }
        else
        {
            if (!isReplacingSameAddress())
            {
                // Historically BROADCAST_INTERVAL was used, but this is unrelated to ring_delay, so using it to know
                // how long to sleep only works with the default settings (ring_delay=30s, broadcast=60s).  For users
                // who are aware of this relationship, this coupling should not be broken, but for most users this
                // relationship isn't known and instead we should rely on the ring_delay.
                // See CASSANDRA-17776
                long sleepDelayMillis = Math.max(LoadBroadcaster.BROADCAST_INTERVAL, ringTimeoutMillis * 2);
                try
                {
                    // Sleep additionally to make sure that the server actually is not alive
                    // and giving it more time to gossip if alive.
                    logger.info("Sleeping for {}ms waiting to make sure no new gossip updates happen for {}", sleepDelayMillis, DatabaseDescriptor.getReplaceAddress());
                    Thread.sleep(sleepDelayMillis);
                }
                catch (InterruptedException e)
                {
                    throw new UncheckedInterruptedException(e);
                }

                // check for operator errors...
                long nanoDelay = MILLISECONDS.toNanos(ringTimeoutMillis);
                for (Token token : bootstrapTokens)
                {
                    InetAddressAndPort existing = tokenMetadata.getEndpoint(token);
                    if (existing != null)
                    {
                        EndpointState endpointStateForExisting = Gossiper.instance.getEndpointStateForEndpoint(existing);
                        long updateTimestamp = endpointStateForExisting.getUpdateTimestamp();
                        long allowedDelay = nanoTime() - nanoDelay;

                        // if the node was updated within the ring delay or the node is alive, we should fail
                        if (updateTimestamp > allowedDelay || endpointStateForExisting.isAlive())
                        {
                            logger.error("Unable to replace node for token={}. The node is reporting as {}alive with updateTimestamp={}, allowedDelay={}",
                                         token, endpointStateForExisting.isAlive() ? "" : "not ", updateTimestamp, allowedDelay);
                            throw new UnsupportedOperationException("Cannot replace a live node... ");
                        }
                        collisions.add(existing);
                    }
                    else
                    {
                        throw new UnsupportedOperationException("Cannot replace token " + token + " which does not exist!");
                    }
                }
            }
            else
            {
                try
                {
                    Thread.sleep(RING_DELAY_MILLIS);
                }
                catch (InterruptedException e)
                {
                    throw new UncheckedInterruptedException(e);
                }

            }
            setMode(Mode.JOINING, "Replacing a node with token(s): " + bootstrapTokens, true);
        }
        return collisions;
    }

    /**
     * Bootstrap node by fetching data from other nodes.
     * If node is bootstrapping as a new node, then this also announces bootstrapping to the cluster.
     *
     * This blocks until streaming is done.
     *
     * @param tokens bootstrapping tokens
     * @return true if bootstrap succeeds.
     */
    @VisibleForTesting
    public boolean bootstrap(final Collection<Token> tokens, long bootstrapTimeoutMillis)
    {
        isBootstrapMode = true;
        SystemKeyspace.updateTokens(tokens); // DON'T use setToken, that makes us part of the ring locally which is incorrect until we are done bootstrapping

        if (!replacing || !isReplacingSameAddress())
        {
            // if not an existing token then bootstrap
            List<Pair<ApplicationState, VersionedValue>> states = new ArrayList<>();
            states.add(Pair.create(ApplicationState.TOKENS, valueFactory.tokens(tokens)));
            states.add(Pair.create(ApplicationState.STATUS_WITH_PORT, replacing?
                                                            valueFactory.bootReplacingWithPort(DatabaseDescriptor.getReplaceAddress()) :
                                                            valueFactory.bootstrapping(tokens)));
            states.add(Pair.create(ApplicationState.STATUS, replacing ?
                                                            valueFactory.bootReplacing(DatabaseDescriptor.getReplaceAddress().getAddress()) :
                                                            valueFactory.bootstrapping(tokens)));
            Gossiper.instance.addLocalApplicationStates(states);
            setMode(Mode.JOINING, "sleeping " + RING_DELAY_MILLIS + " ms for pending range setup", true);
            Uninterruptibles.sleepUninterruptibly(RING_DELAY_MILLIS, MILLISECONDS);
        }
        else
        {
            // Dont set any state for the node which is bootstrapping the existing token...
            tokenMetadata.updateNormalTokens(tokens, FBUtilities.getBroadcastAddressAndPort());
            SystemKeyspace.removeEndpoint(DatabaseDescriptor.getReplaceAddress());
        }
        if (!Gossiper.instance.seenAnySeed())
            throw new IllegalStateException("Unable to contact any seeds: " + Gossiper.instance.getSeeds());

        if (RESET_BOOTSTRAP_PROGRESS.getBoolean())
        {
            logger.info("Resetting bootstrap progress to start fresh");
            SystemKeyspace.resetAvailableStreamedRanges();
        }

        // Force disk boundary invalidation now that local tokens are set
        invalidateLocalRanges();
        repairPaxosForTopologyChange("bootstrap");

        Future<StreamState> bootstrapStream = startBootstrap(tokens);
        try
        {
            if (bootstrapTimeoutMillis > 0)
                bootstrapStream.get(bootstrapTimeoutMillis, MILLISECONDS);
            else
                bootstrapStream.get();
            bootstrapFinished();
            logger.info("Bootstrap completed for tokens {}", tokens);
            return true;
        }
        catch (Throwable e)
        {
            logger.error("Error while waiting on bootstrap to complete. Bootstrap will have to be restarted.", e);
            return false;
        }
    }

    public Future<StreamState> startBootstrap(Collection<Token> tokens)
    {
        return startBootstrap(tokens, replacing);
    }

    public Future<StreamState> startBootstrap(Collection<Token> tokens, boolean replacing)
    {
        setMode(Mode.JOINING, "Starting to bootstrap...", true);
        BootStrapper bootstrapper = new BootStrapper(FBUtilities.getBroadcastAddressAndPort(), tokens, tokenMetadata);
        bootstrapper.addProgressListener(progressSupport);
        return bootstrapper.bootstrap(streamStateStore, useStrictConsistency && !replacing); // handles token update
    }

    private void invalidateLocalRanges()
    {
        for (Keyspace keyspace : Keyspace.all())
        {
            for (ColumnFamilyStore cfs : keyspace.getColumnFamilyStores())
            {
                for (final ColumnFamilyStore store : cfs.concatWithIndexes())
                {
                    store.invalidateLocalRanges();
                }
            }
        }
    }

    /**
     * All MVs have been created during bootstrap, so mark them as built
     */
    private void markViewsAsBuilt()
    {
        for (String keyspace : Schema.instance.getUserKeyspaces().names())
        {
            for (ViewMetadata view: Schema.instance.getKeyspaceMetadata(keyspace).views)
                SystemKeyspace.finishViewBuildStatus(view.keyspace(), view.name());
        }
    }

    /**
     * Called when bootstrap did finish successfully
     */
    private void bootstrapFinished()
    {
        markViewsAsBuilt();
        isBootstrapMode = false;
    }

    @Override
    public String getBootstrapState()
    {
        return SystemKeyspace.getBootstrapState().name();
    }

    public boolean resumeBootstrap()
    {
        if (isBootstrapMode && SystemKeyspace.bootstrapInProgress())
        {
            logger.info("Resuming bootstrap...");

            // get bootstrap tokens saved in system keyspace
            final Collection<Token> tokens = SystemKeyspace.getSavedTokens();
            // already bootstrapped ranges are filtered during bootstrap
            BootStrapper bootstrapper = new BootStrapper(FBUtilities.getBroadcastAddressAndPort(), tokens, tokenMetadata);
            bootstrapper.addProgressListener(progressSupport);
            Future<StreamState> bootstrapStream = bootstrapper.bootstrap(streamStateStore, useStrictConsistency && !replacing); // handles token update
            bootstrapStream.addCallback(new FutureCallback<StreamState>()
            {
                @Override
                public void onSuccess(StreamState streamState)
                {
                    try
                    {
                        bootstrapFinished();
                        if (isSurveyMode)
                        {
                            logger.info("Startup complete, but write survey mode is active, not becoming an active ring member. Use JMX (StorageService->joinRing()) to finalize ring joining.");
                        }
                        else
                        {
                            isSurveyMode = false;
                            progressSupport.progress("bootstrap", ProgressEvent.createNotification("Joining ring..."));
                            finishJoiningRing(true, bootstrapTokens);
                            doAuthSetup(false);
                        }
                        progressSupport.progress("bootstrap", new ProgressEvent(ProgressEventType.COMPLETE, 1, 1, "Resume bootstrap complete"));
                        if (!isNativeTransportRunning())
                            daemon.initializeClientTransports();
                        daemon.start();
                        logger.info("Resume complete");
                    }
                    catch(Exception e)
                    {
                        onFailure(e);
                        throw e;
                    }
                }

                @Override
                public void onFailure(Throwable e)
                {
                    String message = "Error during bootstrap: ";
                    if (e instanceof ExecutionException && e.getCause() != null)
                    {
                        message += e.getCause().getMessage();
                    }
                    else
                    {
                        message += e.getMessage();
                    }
                    logger.error(message, e);
                    progressSupport.progress("bootstrap", new ProgressEvent(ProgressEventType.ERROR, 1, 1, message));
                    progressSupport.progress("bootstrap", new ProgressEvent(ProgressEventType.COMPLETE, 1, 1, "Resume bootstrap complete"));
                }
            });
            return true;
        }
        else
        {
            logger.info("Resuming bootstrap is requested, but the node is already bootstrapped.");
            return false;
        }
    }

    public Map<String,List<Integer>> getConcurrency(List<String> stageNames)
    {
        Stream<Stage> stageStream = stageNames.isEmpty() ? stream(Stage.values()) : stageNames.stream().map(Stage::fromPoolName);
        return stageStream.collect(toMap(s -> s.jmxName,
                                         s -> Arrays.asList(s.getCorePoolSize(), s.getMaximumPoolSize())));
    }

    public void setConcurrency(String threadPoolName, int newCorePoolSize, int newMaximumPoolSize)
    {
        Stage stage = Stage.fromPoolName(threadPoolName);
        if (newCorePoolSize >= 0)
            stage.setCorePoolSize(newCorePoolSize);
        stage.setMaximumPoolSize(newMaximumPoolSize);
    }

    public boolean isBootstrapMode()
    {
        return isBootstrapMode;
    }

    public TokenMetadata getTokenMetadata()
    {
        return tokenMetadata;
    }

    public Map<List<String>, List<String>> getRangeToEndpointMap(String keyspace)
    {
        return getRangeToEndpointMap(keyspace, false);
    }

    public Map<List<String>, List<String>> getRangeToEndpointWithPortMap(String keyspace)
    {
         return getRangeToEndpointMap(keyspace, true);
    }

    /**
     * for a keyspace, return the ranges and corresponding listen addresses.
     * @param keyspace
     * @return the endpoint map
     */
    public Map<List<String>, List<String>> getRangeToEndpointMap(String keyspace, boolean withPort)
    {
        /* All the ranges for the tokens */
        Map<List<String>, List<String>> map = new HashMap<>();
        for (Map.Entry<Range<Token>, EndpointsForRange> entry : getRangeToAddressMap(keyspace).entrySet())
        {
            map.put(entry.getKey().asList(), Replicas.stringify(entry.getValue(), withPort));
        }
        return map;
    }

    /**
     * Return the native address associated with an endpoint as a string.
     * @param endpoint The endpoint to get rpc address for
     * @return the native address
     */
    public String getNativeaddress(InetAddressAndPort endpoint, boolean withPort)
    {
        if (endpoint.equals(FBUtilities.getBroadcastAddressAndPort()))
            return FBUtilities.getBroadcastNativeAddressAndPort().getHostAddress(withPort);
        else if (Gossiper.instance.getEndpointStateForEndpoint(endpoint).getApplicationState(ApplicationState.NATIVE_ADDRESS_AND_PORT) != null)
        {
            try
            {
                InetAddressAndPort address = InetAddressAndPort.getByName(Gossiper.instance.getEndpointStateForEndpoint(endpoint).getApplicationState(ApplicationState.NATIVE_ADDRESS_AND_PORT).value);
                return address.getHostAddress(withPort);
            }
            catch (UnknownHostException e)
            {
                throw new RuntimeException(e);
            }
        }
        else
        {
             final String ipAddress;
             // If RPC_ADDRESS present in gossip for this endpoint use it.  This is expected for 3.x nodes.
             if (Gossiper.instance.getEndpointStateForEndpoint(endpoint).getApplicationState(ApplicationState.RPC_ADDRESS) != null)
             {
                 ipAddress = Gossiper.instance.getEndpointStateForEndpoint(endpoint).getApplicationState(ApplicationState.RPC_ADDRESS).value;
             }
             else
             {
                 // otherwise just use the IP of the endpoint itself.
                 ipAddress = endpoint.getHostAddress(false);
             }

             // include the configured native_transport_port.
             try
             {
                 InetAddressAndPort address = InetAddressAndPort.getByNameOverrideDefaults(ipAddress, DatabaseDescriptor.getNativeTransportPort());
                 return address.getHostAddress(withPort);
             }
             catch (UnknownHostException e)
             {
                 throw new RuntimeException(e);
             }
         }
    }

    public Map<List<String>, List<String>> getRangeToRpcaddressMap(String keyspace)
    {
        return getRangeToNativeaddressMap(keyspace, false);
    }

    public Map<List<String>, List<String>> getRangeToNativeaddressWithPortMap(String keyspace)
    {
        return getRangeToNativeaddressMap(keyspace, true);
    }

    /**
     * for a keyspace, return the ranges and corresponding RPC addresses for a given keyspace.
     * @param keyspace
     * @return the endpoint map
     */
    private Map<List<String>, List<String>> getRangeToNativeaddressMap(String keyspace, boolean withPort)
    {
        /* All the ranges for the tokens */
        Map<List<String>, List<String>> map = new HashMap<>();
        for (Map.Entry<Range<Token>, EndpointsForRange> entry : getRangeToAddressMap(keyspace).entrySet())
        {
            List<String> rpcaddrs = new ArrayList<>(entry.getValue().size());
            for (Replica replicas: entry.getValue())
            {
                rpcaddrs.add(getNativeaddress(replicas.endpoint(), withPort));
            }
            map.put(entry.getKey().asList(), rpcaddrs);
        }
        return map;
    }

    public Map<List<String>, List<String>> getPendingRangeToEndpointMap(String keyspace)
    {
        return getPendingRangeToEndpointMap(keyspace, false);
    }

    public Map<List<String>, List<String>> getPendingRangeToEndpointWithPortMap(String keyspace)
    {
        return getPendingRangeToEndpointMap(keyspace, true);
    }

    private Map<List<String>, List<String>> getPendingRangeToEndpointMap(String keyspace, boolean withPort)
    {
        // some people just want to get a visual representation of things. Allow null and set it to the first
        // non-system keyspace.
        if (keyspace == null)
            keyspace = Schema.instance.getNonLocalStrategyKeyspaces().iterator().next().name;

        Map<List<String>, List<String>> map = new HashMap<>();
        for (Map.Entry<Range<Token>, EndpointsForRange> entry : tokenMetadata.getPendingRangesMM(keyspace).asMap().entrySet())
        {
            map.put(entry.getKey().asList(), Replicas.stringify(entry.getValue(), withPort));
        }
        return map;
    }

    public EndpointsByRange getRangeToAddressMap(String keyspace)
    {
        return getRangeToAddressMap(keyspace, tokenMetadata.sortedTokens());
    }

    public EndpointsByRange getRangeToAddressMapInLocalDC(String keyspace)
    {
        Predicate<Replica> isLocalDC = replica -> isLocalDC(replica.endpoint());

        EndpointsByRange origMap = getRangeToAddressMap(keyspace, getTokensInLocalDC());
        Map<Range<Token>, EndpointsForRange> filteredMap = Maps.newHashMap();
        for (Map.Entry<Range<Token>, EndpointsForRange> entry : origMap.entrySet())
        {
            EndpointsForRange endpointsInLocalDC = entry.getValue().filter(isLocalDC);
            filteredMap.put(entry.getKey(), endpointsInLocalDC);
        }

        return new EndpointsByRange(filteredMap);
    }

    private List<Token> getTokensInLocalDC()
    {
        List<Token> filteredTokens = Lists.newArrayList();
        for (Token token : tokenMetadata.sortedTokens())
        {
            InetAddressAndPort endpoint = tokenMetadata.getEndpoint(token);
            if (isLocalDC(endpoint))
                filteredTokens.add(token);
        }
        return filteredTokens;
    }

    private boolean isLocalDC(InetAddressAndPort targetHost)
    {
        String remoteDC = DatabaseDescriptor.getEndpointSnitch().getDatacenter(targetHost);
        String localDC = DatabaseDescriptor.getEndpointSnitch().getLocalDatacenter();
        return remoteDC.equals(localDC);
    }

    private EndpointsByRange getRangeToAddressMap(String keyspace, List<Token> sortedTokens)
    {
        // some people just want to get a visual representation of things. Allow null and set it to the first
        // non-system keyspace.
        if (keyspace == null)
            keyspace = Schema.instance.getNonLocalStrategyKeyspaces().iterator().next().name;

        List<Range<Token>> ranges = getAllRanges(sortedTokens);
        return constructRangeToEndpointMap(keyspace, ranges);
    }


    public List<String> describeRingJMX(String keyspace) throws IOException
    {
        return describeRingJMX(keyspace, false);
    }

    public List<String> describeRingWithPortJMX(String keyspace) throws IOException
    {
        return describeRingJMX(keyspace,true);
    }

    /**
     * The same as {@code describeRing(String)} but converts TokenRange to the String for JMX compatibility
     *
     * @param keyspace The keyspace to fetch information about
     *
     * @return a List of TokenRange(s) converted to String for the given keyspace
     */
    private List<String> describeRingJMX(String keyspace, boolean withPort) throws IOException
    {
        List<TokenRange> tokenRanges;
        try
        {
            tokenRanges = describeRing(keyspace, false, withPort);
        }
        catch (InvalidRequestException e)
        {
            throw new IOException(e.getMessage());
        }
        List<String> result = new ArrayList<>(tokenRanges.size());

        for (TokenRange tokenRange : tokenRanges)
            result.add(tokenRange.toString(withPort));

        return result;
    }

    /**
     * The TokenRange for a given keyspace.
     *
     * @param keyspace The keyspace to fetch information about
     *
     * @return a List of TokenRange(s) for the given keyspace
     *
     * @throws InvalidRequestException if there is no ring information available about keyspace
     */
    public List<TokenRange> describeRing(String keyspace) throws InvalidRequestException
    {
        return describeRing(keyspace, false, false);
    }

    /**
     * The same as {@code describeRing(String)} but considers only the part of the ring formed by nodes in the local DC.
     */
    public List<TokenRange> describeLocalRing(String keyspace) throws InvalidRequestException
    {
        return describeRing(keyspace, true, false);
    }

    private List<TokenRange> describeRing(String keyspace, boolean includeOnlyLocalDC, boolean withPort) throws InvalidRequestException
    {
        if (!Schema.instance.getKeyspaces().contains(keyspace))
            throw new InvalidRequestException("No such keyspace: " + keyspace);

        if (keyspace == null || Keyspace.open(keyspace).getReplicationStrategy() instanceof LocalStrategy)
            throw new InvalidRequestException("There is no ring for the keyspace: " + keyspace);

        List<TokenRange> ranges = new ArrayList<>();
        Token.TokenFactory tf = getTokenFactory();

        EndpointsByRange rangeToAddressMap =
                includeOnlyLocalDC
                        ? getRangeToAddressMapInLocalDC(keyspace)
                        : getRangeToAddressMap(keyspace);

        for (Map.Entry<Range<Token>, EndpointsForRange> entry : rangeToAddressMap.entrySet())
            ranges.add(TokenRange.create(tf, entry.getKey(), ImmutableList.copyOf(entry.getValue().endpoints()), withPort));

        return ranges;
    }

    public Map<String, String> getTokenToEndpointMap()
    {
        return getTokenToEndpointMap(false);
    }

    public Map<String, String> getTokenToEndpointWithPortMap()
    {
        return getTokenToEndpointMap(true);
    }

    private Map<String, String> getTokenToEndpointMap(boolean withPort)
    {
        Map<Token, InetAddressAndPort> mapInetAddress = tokenMetadata.getNormalAndBootstrappingTokenToEndpointMap();
        // in order to preserve tokens in ascending order, we use LinkedHashMap here
        Map<String, String> mapString = new LinkedHashMap<>(mapInetAddress.size());
        List<Token> tokens = new ArrayList<>(mapInetAddress.keySet());
        Collections.sort(tokens);
        for (Token token : tokens)
        {
            mapString.put(token.toString(), mapInetAddress.get(token).getHostAddress(withPort));
        }
        return mapString;
    }

    public String getLocalHostId()
    {
        UUID id = getLocalHostUUID();
        return id != null ? id.toString() : null;
    }

    public UUID getLocalHostUUID()
    {
        UUID id = getTokenMetadata().getHostId(FBUtilities.getBroadcastAddressAndPort());
        if (id != null)
            return id;
        // this condition is to prevent accessing the tables when the node is not started yet, and in particular,
        // when it is not going to be started at all (e.g. when running some unit tests or client tools).
        else if ((DatabaseDescriptor.isDaemonInitialized() || DatabaseDescriptor.isToolInitialized()) && CommitLog.instance.isStarted())
            return SystemKeyspace.getLocalHostId();

        return null;
    }

    public Map<String, String> getHostIdMap()
    {
        return getEndpointToHostId();
    }


    public Map<String, String> getEndpointToHostId()
    {
        return getEndpointToHostId(false);
    }

    public Map<String, String> getEndpointWithPortToHostId()
    {
        return getEndpointToHostId(true);
    }

    private  Map<String, String> getEndpointToHostId(boolean withPort)
    {
        Map<String, String> mapOut = new HashMap<>();
        for (Map.Entry<InetAddressAndPort, UUID> entry : getTokenMetadata().getEndpointToHostIdMapForReading().entrySet())
            mapOut.put(entry.getKey().getHostAddress(withPort), entry.getValue().toString());
        return mapOut;
    }

    public Map<String, String> getHostIdToEndpoint()
    {
        return getHostIdToEndpoint(false);
    }

    public Map<String, String> getHostIdToEndpointWithPort()
    {
        return getHostIdToEndpoint(true);
    }

    private Map<String, String> getHostIdToEndpoint(boolean withPort)
    {
        Map<String, String> mapOut = new HashMap<>();
        for (Map.Entry<InetAddressAndPort, UUID> entry : getTokenMetadata().getEndpointToHostIdMapForReading().entrySet())
            mapOut.put(entry.getValue().toString(), entry.getKey().getHostAddress(withPort));
        return mapOut;
    }

    /**
     * Construct the range to endpoint mapping based on the true view
     * of the world.
     * @param ranges
     * @return mapping of ranges to the replicas responsible for them.
    */
    private EndpointsByRange constructRangeToEndpointMap(String keyspace, List<Range<Token>> ranges)
    {
        AbstractReplicationStrategy strategy = Keyspace.open(keyspace).getReplicationStrategy();
        Map<Range<Token>, EndpointsForRange> rangeToEndpointMap = new HashMap<>(ranges.size());
        for (Range<Token> range : ranges)
            rangeToEndpointMap.put(range, strategy.getNaturalReplicas(range.right));
        return new EndpointsByRange(rangeToEndpointMap);
    }

    public void beforeChange(InetAddressAndPort endpoint, EndpointState currentState, ApplicationState newStateKey, VersionedValue newValue)
    {
        // no-op
    }

    /*
     * Handle the reception of a new particular ApplicationState for a particular endpoint. Note that the value of the
     * ApplicationState has not necessarily "changed" since the last known value, if we already received the same update
     * from somewhere else.
     *
     * onChange only ever sees one ApplicationState piece change at a time (even if many ApplicationState updates were
     * received at the same time), so we perform a kind of state machine here. We are concerned with two events: knowing
     * the token associated with an endpoint, and knowing its operation mode. Nodes can start in either bootstrap or
     * normal mode, and from bootstrap mode can change mode to normal. A node in bootstrap mode needs to have
     * pendingranges set in TokenMetadata; a node in normal mode should instead be part of the token ring.
     *
     * Normal progression of ApplicationState.STATUS values for a node should be like this:
     * STATUS_BOOTSTRAPPING,token
     *   if bootstrapping. stays this way until all files are received.
     * STATUS_NORMAL,token
     *   ready to serve reads and writes.
     * STATUS_LEAVING,token
     *   get ready to leave the cluster as part of a decommission
     * STATUS_LEFT,token
     *   set after decommission is completed.
     *
     * Other STATUS values that may be seen (possibly anywhere in the normal progression):
     * STATUS_MOVING,newtoken
     *   set if node is currently moving to a new token in the ring
     * REMOVING_TOKEN,deadtoken
     *   set if the node is dead and is being removed by its REMOVAL_COORDINATOR
     * REMOVED_TOKEN,deadtoken
     *   set if the node is dead and has been removed by its REMOVAL_COORDINATOR
     *
     * Note: Any time a node state changes from STATUS_NORMAL, it will not be visible to new nodes. So it follows that
     * you should never bootstrap a new node during a removenode, decommission or move.
     */
    public void onChange(InetAddressAndPort endpoint, ApplicationState state, VersionedValue value)
    {
        if (state == ApplicationState.STATUS || state == ApplicationState.STATUS_WITH_PORT)
        {
            String[] pieces = splitValue(value);
            assert (pieces.length > 0);

            String moveName = pieces[0];

            switch (moveName)
            {
                case VersionedValue.STATUS_BOOTSTRAPPING_REPLACE:
                    handleStateBootreplacing(endpoint, pieces);
                    break;
                case VersionedValue.STATUS_BOOTSTRAPPING:
                    handleStateBootstrap(endpoint);
                    break;
                case VersionedValue.STATUS_NORMAL:
                    handleStateNormal(endpoint, VersionedValue.STATUS_NORMAL);
                    break;
                case VersionedValue.SHUTDOWN:
                    handleStateNormal(endpoint, VersionedValue.SHUTDOWN);
                    break;
                case VersionedValue.REMOVING_TOKEN:
                case VersionedValue.REMOVED_TOKEN:
                    handleStateRemoving(endpoint, pieces);
                    break;
                case VersionedValue.STATUS_LEAVING:
                    handleStateLeaving(endpoint);
                    break;
                case VersionedValue.STATUS_LEFT:
                    handleStateLeft(endpoint, pieces);
                    break;
                case VersionedValue.STATUS_MOVING:
                    handleStateMoving(endpoint, pieces);
                    break;
            }
        }
        else
        {
            EndpointState epState = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
            if (epState == null || Gossiper.instance.isDeadState(epState))
            {
                logger.debug("Ignoring state change for dead or unknown endpoint: {}", endpoint);
                return;
            }

            if (getTokenMetadata().isMember(endpoint))
            {
                switch (state)
                {
                    case RELEASE_VERSION:
                        SystemKeyspace.updatePeerInfo(endpoint, "release_version", value.value);
                        break;
                    case DC:
                        updateTopology(endpoint);
                        SystemKeyspace.updatePeerInfo(endpoint, "data_center", value.value);
                        break;
                    case RACK:
                        updateTopology(endpoint);
                        SystemKeyspace.updatePeerInfo(endpoint, "rack", value.value);
                        break;
                    case RPC_ADDRESS:
                        try
                        {
                            SystemKeyspace.updatePeerInfo(endpoint, "rpc_address", InetAddress.getByName(value.value));
                        }
                        catch (UnknownHostException e)
                        {
                            throw new RuntimeException(e);
                        }
                        break;
                    case NATIVE_ADDRESS_AND_PORT:
                        try
                        {
                            InetAddressAndPort address = InetAddressAndPort.getByName(value.value);
                            SystemKeyspace.updatePeerNativeAddress(endpoint, address);
                        }
                        catch (UnknownHostException e)
                        {
                            throw new RuntimeException(e);
                        }
                        break;
                    case SCHEMA:
                        SystemKeyspace.updatePeerInfo(endpoint, "schema_version", UUID.fromString(value.value));
                        break;
                    case HOST_ID:
                        SystemKeyspace.updatePeerInfo(endpoint, "host_id", UUID.fromString(value.value));
                        break;
                    case RPC_READY:
                        notifyRpcChange(endpoint, epState.isRpcReady());
                        break;
                    case NET_VERSION:
                        updateNetVersion(endpoint, value);
                        break;
                }
            }
            else
            {
                logger.debug("Ignoring application state {} from {} because it is not a member in token metadata",
                             state, endpoint);
            }
        }
    }

    private static String[] splitValue(VersionedValue value)
    {
        return value.value.split(VersionedValue.DELIMITER_STR, -1);
    }

    private void updateNetVersion(InetAddressAndPort endpoint, VersionedValue value)
    {
        try
        {
            MessagingService.instance().versions.set(endpoint, Integer.parseInt(value.value));
        }
        catch (NumberFormatException e)
        {
            throw new AssertionError("Got invalid value for NET_VERSION application state: " + value.value);
        }
    }

    public void updateTopology(InetAddressAndPort endpoint)
    {
        if (getTokenMetadata().isMember(endpoint))
        {
            getTokenMetadata().updateTopology(endpoint);
        }
    }

    public void updateTopology()
    {
        getTokenMetadata().updateTopology();
    }

    private void updatePeerInfo(InetAddressAndPort endpoint)
    {
        EndpointState epState = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
        InetAddress native_address = null;
        int native_port = DatabaseDescriptor.getNativeTransportPort();

        for (Map.Entry<ApplicationState, VersionedValue> entry : epState.states())
        {
            switch (entry.getKey())
            {
                case RELEASE_VERSION:
                    SystemKeyspace.updatePeerInfo(endpoint, "release_version", entry.getValue().value);
                    break;
                case DC:
                    SystemKeyspace.updatePeerInfo(endpoint, "data_center", entry.getValue().value);
                    break;
                case RACK:
                    SystemKeyspace.updatePeerInfo(endpoint, "rack", entry.getValue().value);
                    break;
                case RPC_ADDRESS:
                    try
                    {
                        native_address = InetAddress.getByName(entry.getValue().value);
                    }
                    catch (UnknownHostException e)
                    {
                        throw new RuntimeException(e);
                    }
                    break;
                case NATIVE_ADDRESS_AND_PORT:
                    try
                    {
                        InetAddressAndPort address = InetAddressAndPort.getByName(entry.getValue().value);
                        native_address = address.getAddress();
                        native_port = address.getPort();
                    }
                    catch (UnknownHostException e)
                    {
                        throw new RuntimeException(e);
                    }
                    break;
                case SCHEMA:
                    SystemKeyspace.updatePeerInfo(endpoint, "schema_version", UUID.fromString(entry.getValue().value));
                    break;
                case HOST_ID:
                    SystemKeyspace.updatePeerInfo(endpoint, "host_id", UUID.fromString(entry.getValue().value));
                    break;
            }
        }

        //Some tests won't set all the states
        if (native_address != null)
        {
            SystemKeyspace.updatePeerNativeAddress(endpoint,
                                                   InetAddressAndPort.getByAddressOverrideDefaults(native_address,
                                                                                                   native_port));
        }
    }

    private void notifyRpcChange(InetAddressAndPort endpoint, boolean ready)
    {
        if (ready)
            notifyUp(endpoint);
        else
            notifyDown(endpoint);
    }

    private void notifyUp(InetAddressAndPort endpoint)
    {
        if (!isRpcReady(endpoint) || !Gossiper.instance.isAlive(endpoint))
            return;

        for (IEndpointLifecycleSubscriber subscriber : lifecycleSubscribers)
            subscriber.onUp(endpoint);
    }

    private void notifyDown(InetAddressAndPort endpoint)
    {
        for (IEndpointLifecycleSubscriber subscriber : lifecycleSubscribers)
            subscriber.onDown(endpoint);
    }

    private void notifyJoined(InetAddressAndPort endpoint)
    {
        if (!isStatus(endpoint, VersionedValue.STATUS_NORMAL))
            return;

        for (IEndpointLifecycleSubscriber subscriber : lifecycleSubscribers)
            subscriber.onJoinCluster(endpoint);
    }

    private void notifyMoved(InetAddressAndPort endpoint)
    {
        for (IEndpointLifecycleSubscriber subscriber : lifecycleSubscribers)
            subscriber.onMove(endpoint);
    }

    private void notifyLeft(InetAddressAndPort endpoint)
    {
        for (IEndpointLifecycleSubscriber subscriber : lifecycleSubscribers)
            subscriber.onLeaveCluster(endpoint);
    }

    private boolean isStatus(InetAddressAndPort endpoint, String status)
    {
        EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
        return state != null && state.getStatus().equals(status);
    }

    public boolean isRpcReady(InetAddressAndPort endpoint)
    {
        EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
        return state != null && state.isRpcReady();
    }

    /**
     * Set the RPC status. Because when draining a node we need to set the RPC
     * status to not ready, and drain is called by the shutdown hook, it may be that value is false
     * and there is no local endpoint state. In this case it's OK to just do nothing. Therefore,
     * we assert that the local endpoint state is not null only when value is true.
     *
     * @param value - true indicates that RPC is ready, false indicates the opposite.
     */
    public void setRpcReady(boolean value)
    {
        EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(FBUtilities.getBroadcastAddressAndPort());
        // if value is false we're OK with a null state, if it is true we are not.
        assert !value || state != null;

        if (state != null)
            Gossiper.instance.addLocalApplicationState(ApplicationState.RPC_READY, valueFactory.rpcReady(value));
    }

    private Collection<Token> getTokensFor(InetAddressAndPort endpoint)
    {
        try
        {
            EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
            if (state == null)
                return Collections.emptyList();

            VersionedValue versionedValue = state.getApplicationState(ApplicationState.TOKENS);
            if (versionedValue == null)
                return Collections.emptyList();

            return TokenSerializer.deserialize(tokenMetadata.partitioner, new DataInputStream(new ByteArrayInputStream(versionedValue.toBytes())));
        }
        catch (IOException e)
        {
            throw new RuntimeException(e);
        }
    }

    /**
     * Handle node bootstrap
     *
     * @param endpoint bootstrapping node
     */
    private void handleStateBootstrap(InetAddressAndPort endpoint)
    {
        Collection<Token> tokens;
        // explicitly check for TOKENS, because a bootstrapping node might be bootstrapping in legacy mode; that is, not using vnodes and no token specified
        tokens = getTokensFor(endpoint);

        if (logger.isDebugEnabled())
            logger.debug("Node {} state bootstrapping, token {}", endpoint, tokens);

        // if this node is present in token metadata, either we have missed intermediate states
        // or the node had crashed. Print warning if needed, clear obsolete stuff and
        // continue.
        if (tokenMetadata.isMember(endpoint))
        {
            // If isLeaving is false, we have missed both LEAVING and LEFT. However, if
            // isLeaving is true, we have only missed LEFT. Waiting time between completing
            // leave operation and rebootstrapping is relatively short, so the latter is quite
            // common (not enough time for gossip to spread). Therefore we report only the
            // former in the log.
            if (!tokenMetadata.isLeaving(endpoint))
                logger.info("Node {} state jump to bootstrap", endpoint);
            tokenMetadata.removeEndpoint(endpoint);
        }

        tokenMetadata.addBootstrapTokens(tokens, endpoint);
        PendingRangeCalculatorService.instance.update();

        tokenMetadata.updateHostId(Gossiper.instance.getHostId(endpoint), endpoint);
    }

    private void handleStateBootreplacing(InetAddressAndPort newNode, String[] pieces)
    {
        InetAddressAndPort oldNode;
        try
        {
            oldNode = InetAddressAndPort.getByName(pieces[1]);
        }
        catch (Exception e)
        {
            logger.error("Node {} tried to replace malformed endpoint {}.", newNode, pieces[1], e);
            return;
        }

        if (FailureDetector.instance.isAlive(oldNode))
        {
            throw new RuntimeException(String.format("Node %s is trying to replace alive node %s.", newNode, oldNode));
        }

        Optional<InetAddressAndPort> replacingNode = tokenMetadata.getReplacingNode(newNode);
        if (replacingNode.isPresent() && !replacingNode.get().equals(oldNode))
        {
            throw new RuntimeException(String.format("Node %s is already replacing %s but is trying to replace %s.",
                                                     newNode, replacingNode.get(), oldNode));
        }

        Collection<Token> tokens = getTokensFor(newNode);

        if (logger.isDebugEnabled())
            logger.debug("Node {} is replacing {}, tokens {}", newNode, oldNode, tokens);

        tokenMetadata.addReplaceTokens(tokens, newNode, oldNode);
        PendingRangeCalculatorService.instance.update();

        tokenMetadata.updateHostId(Gossiper.instance.getHostId(newNode), newNode);
    }

    private void ensureUpToDateTokenMetadata(String status, InetAddressAndPort endpoint)
    {
        Set<Token> tokens = new TreeSet<>(getTokensFor(endpoint));

        if (logger.isDebugEnabled())
            logger.debug("Node {} state {}, tokens {}", endpoint, status, tokens);

        // If the node is previously unknown or tokens do not match, update tokenmetadata to
        // have this node as 'normal' (it must have been using this token before the
        // leave). This way we'll get pending ranges right.
        if (!tokenMetadata.isMember(endpoint))
        {
            logger.info("Node {} state jump to {}", endpoint, status);
            updateTokenMetadata(endpoint, tokens);
        }
        else if (!tokens.equals(new TreeSet<>(tokenMetadata.getTokens(endpoint))))
        {
            logger.warn("Node {} '{}' token mismatch. Long network partition?", endpoint, status);
            updateTokenMetadata(endpoint, tokens);
        }
    }

    private void updateTokenMetadata(InetAddressAndPort endpoint, Iterable<Token> tokens)
    {
        updateTokenMetadata(endpoint, tokens, new HashSet<>());
    }

    private void updateTokenMetadata(InetAddressAndPort endpoint, Iterable<Token> tokens, Set<InetAddressAndPort> endpointsToRemove)
    {
        Set<Token> tokensToUpdateInMetadata = new HashSet<>();
        Set<Token> tokensToUpdateInSystemKeyspace = new HashSet<>();

        for (final Token token : tokens)
        {
            // we don't want to update if this node is responsible for the token and it has a later startup time than endpoint.
            InetAddressAndPort currentOwner = tokenMetadata.getEndpoint(token);
            if (currentOwner == null)
            {
                logger.debug("New node {} at token {}", endpoint, token);
                tokensToUpdateInMetadata.add(token);
                tokensToUpdateInSystemKeyspace.add(token);
            }
            else if (endpoint.equals(currentOwner))
            {
                // set state back to normal, since the node may have tried to leave, but failed and is now back up
                tokensToUpdateInMetadata.add(token);
                tokensToUpdateInSystemKeyspace.add(token);
            }
            // Note: in test scenarios, there may not be any delta between the heartbeat generations of the old
            // and new nodes, so we first check whether the new endpoint is marked as a replacement for the old.
            else if (endpoint.equals(tokenMetadata.getReplacementNode(currentOwner).orElse(null)) || Gossiper.instance.compareEndpointStartup(endpoint, currentOwner) > 0)
            {
                tokensToUpdateInMetadata.add(token);
                tokensToUpdateInSystemKeyspace.add(token);

                // currentOwner is no longer current, endpoint is.  Keep track of these moves, because when
                // a host no longer has any tokens, we'll want to remove it.
                Multimap<InetAddressAndPort, Token> epToTokenCopy = getTokenMetadata().getEndpointToTokenMapForReading();
                epToTokenCopy.get(currentOwner).remove(token);
                if (epToTokenCopy.get(currentOwner).isEmpty())
                    endpointsToRemove.add(currentOwner);

                logger.info("Nodes {} and {} have the same token {}. {} is the new owner", endpoint, currentOwner, token, endpoint);
            }
            else
            {
                logger.info("Nodes {} and {} have the same token {}.  Ignoring {}", endpoint, currentOwner, token, endpoint);
            }
        }

        tokenMetadata.updateNormalTokens(tokensToUpdateInMetadata, endpoint);
        for (InetAddressAndPort ep : endpointsToRemove)
        {
            removeEndpoint(ep);
            if (replacing && ep.equals(DatabaseDescriptor.getReplaceAddress()))
                Gossiper.instance.replacementQuarantine(ep); // quarantine locally longer than normally; see CASSANDRA-8260
        }
        if (!tokensToUpdateInSystemKeyspace.isEmpty())
            SystemKeyspace.updateTokens(endpoint, tokensToUpdateInSystemKeyspace);

        // Tokens changed, the local range ownership probably changed too.
        invalidateLocalRanges();
    }

    @VisibleForTesting
    public boolean isReplacingSameHostAddressAndHostId(UUID hostId)
    {
        try
        {
            return isReplacingSameAddress() &&
                    Gossiper.instance.getEndpointStateForEndpoint(DatabaseDescriptor.getReplaceAddress()) != null
                    && hostId.equals(Gossiper.instance.getHostId(DatabaseDescriptor.getReplaceAddress()));
        }
        catch (RuntimeException ex)
        {
            // If a host is decomissioned and the DNS entry is removed before the
            // bootstrap completes, when it completes and advertises NORMAL state to other nodes, they will be unable
            // to resolve it to an InetAddress unless it happens to be cached. This could happen on nodes
            // storing large amounts of data or with long index rebuild times or if new instances have been added
            // to the cluster through expansion or additional host replacement.
            //
            // The original host replacement must have been able to resolve the replacing address on startup
            // when setting StorageService.replacing, so if it is impossible to resolve now it is probably
            // decommissioned and did not have the same IP address or host id.  Allow the handleStateNormal
            // handling to proceed, otherwise gossip state will be inconistent with some nodes believing the
            // replacement host to be normal, and nodes unable to resolve the hostname will be left in JOINING.
            if (ex.getCause() != null && ex.getCause().getClass() == UnknownHostException.class)
            {
                logger.info("Suppressed exception while checking isReplacingSameHostAddressAndHostId({}). Original host was probably decommissioned. ({})",
                        hostId, ex.getMessage());
                return false;
            }
            throw ex; // otherwise rethrow
        }
    }

    /**
     * Handle node move to normal state. That is, node is entering token ring and participating
     * in reads.
     *
     * @param endpoint node
     */
    private void handleStateNormal(final InetAddressAndPort endpoint, final String status)
    {
        Collection<Token> tokens = getTokensFor(endpoint);
        Set<InetAddressAndPort> endpointsToRemove = new HashSet<>();

        if (logger.isDebugEnabled())
            logger.debug("Node {} state {}, token {}", endpoint, status, tokens);

        if (tokenMetadata.isMember(endpoint))
            logger.info("Node {} state jump to {}", endpoint, status);

        if (tokens.isEmpty() && status.equals(VersionedValue.STATUS_NORMAL))
            logger.error("Node {} is in state normal but it has no tokens, state: {}",
                         endpoint,
                         Gossiper.instance.getEndpointStateForEndpoint(endpoint));

        Optional<InetAddressAndPort> replacingNode = tokenMetadata.getReplacingNode(endpoint);
        if (replacingNode.isPresent())
        {
            assert !endpoint.equals(replacingNode.get()) : "Pending replacement endpoint with same address is not supported";
            logger.info("Node {} will complete replacement of {} for tokens {}", endpoint, replacingNode.get(), tokens);
            if (FailureDetector.instance.isAlive(replacingNode.get()))
            {
                logger.error("Node {} cannot complete replacement of alive node {}.", endpoint, replacingNode.get());
                return;
            }
            endpointsToRemove.add(replacingNode.get());
        }

        Optional<InetAddressAndPort> replacementNode = tokenMetadata.getReplacementNode(endpoint);
        if (replacementNode.isPresent())
        {
            logger.warn("Node {} is currently being replaced by node {}.", endpoint, replacementNode.get());
        }

        updatePeerInfo(endpoint);
        // Order Matters, TM.updateHostID() should be called before TM.updateNormalToken(), (see CASSANDRA-4300).
        UUID hostId = Gossiper.instance.getHostId(endpoint);
        InetAddressAndPort existing = tokenMetadata.getEndpointForHostId(hostId);
        if (replacing && isReplacingSameHostAddressAndHostId(hostId))
        {
            logger.warn("Not updating token metadata for {} because I am replacing it", endpoint);
        }
        else
        {
            if (existing != null && !existing.equals(endpoint))
            {
                if (existing.equals(FBUtilities.getBroadcastAddressAndPort()))
                {
                    logger.warn("Not updating host ID {} for {} because it's mine", hostId, endpoint);
                    tokenMetadata.removeEndpoint(endpoint);
                    endpointsToRemove.add(endpoint);
                }
                else if (Gossiper.instance.compareEndpointStartup(endpoint, existing) > 0)
                {
                    logger.warn("Host ID collision for {} between {} and {}; {} is the new owner", hostId, existing, endpoint, endpoint);
                    tokenMetadata.removeEndpoint(existing);
                    endpointsToRemove.add(existing);
                    tokenMetadata.updateHostId(hostId, endpoint);
                }
                else
                {
                    logger.warn("Host ID collision for {} between {} and {}; ignored {}", hostId, existing, endpoint, endpoint);
                    tokenMetadata.removeEndpoint(endpoint);
                    endpointsToRemove.add(endpoint);
                }
            }
            else
                tokenMetadata.updateHostId(hostId, endpoint);
        }

        // capture because updateNormalTokens clears moving and member status
        boolean isMember = tokenMetadata.isMember(endpoint);
        boolean isMoving = tokenMetadata.isMoving(endpoint);

        updateTokenMetadata(endpoint, tokens, endpointsToRemove);

        if (isMoving || operationMode == Mode.MOVING)
        {
            tokenMetadata.removeFromMoving(endpoint);
            // The above may change the local ownership.
            invalidateLocalRanges();
            notifyMoved(endpoint);
        }
        else if (!isMember) // prior to this, the node was not a member
        {
            notifyJoined(endpoint);
        }

        PendingRangeCalculatorService.instance.update();
    }

    /**
     * Handle node preparing to leave the ring
     *
     * @param endpoint node
     */
    private void handleStateLeaving(InetAddressAndPort endpoint)
    {
        // If the node is previously unknown or tokens do not match, update tokenmetadata to
        // have this node as 'normal' (it must have been using this token before the
        // leave). This way we'll get pending ranges right.

        ensureUpToDateTokenMetadata(VersionedValue.STATUS_LEAVING, endpoint);

        // at this point the endpoint is certainly a member with this token, so let's proceed
        // normally
        tokenMetadata.addLeavingEndpoint(endpoint);
        PendingRangeCalculatorService.instance.update();
    }

    /**
     * Handle node leaving the ring. This will happen when a node is decommissioned
     *
     * @param endpoint If reason for leaving is decommission, endpoint is the leaving node.
     * @param pieces STATE_LEFT,token
     */
    private void handleStateLeft(InetAddressAndPort endpoint, String[] pieces)
    {
        assert pieces.length >= 2;
        Collection<Token> tokens = getTokensFor(endpoint);

        if (logger.isDebugEnabled())
            logger.debug("Node {} state left, tokens {}", endpoint, tokens);

        excise(tokens, endpoint, extractExpireTime(pieces));
    }

    /**
     * Handle node moving inside the ring.
     *
     * @param endpoint moving endpoint address
     * @param pieces STATE_MOVING, token
     */
    private void handleStateMoving(InetAddressAndPort endpoint, String[] pieces)
    {
        ensureUpToDateTokenMetadata(VersionedValue.STATUS_MOVING, endpoint);

        assert pieces.length >= 2;
        Token token = getTokenFactory().fromString(pieces[1]);

        if (logger.isDebugEnabled())
            logger.debug("Node {} state moving, new token {}", endpoint, token);

        tokenMetadata.addMovingEndpoint(token, endpoint);

        PendingRangeCalculatorService.instance.update();
    }

    /**
     * Handle notification that a node being actively removed from the ring via 'removenode'
     *
     * @param endpoint node
     * @param pieces either REMOVED_TOKEN (node is gone) or REMOVING_TOKEN (replicas need to be restored)
     */
    private void handleStateRemoving(InetAddressAndPort endpoint, String[] pieces)
    {
        assert (pieces.length > 0);

        if (endpoint.equals(FBUtilities.getBroadcastAddressAndPort()))
        {
            logger.info("Received removenode gossip about myself. Is this node rejoining after an explicit removenode?");
            try
            {
                drain();
            }
            catch (Exception e)
            {
                throw new RuntimeException(e);
            }
            return;
        }
        if (tokenMetadata.isMember(endpoint))
        {
            String state = pieces[0];
            Collection<Token> removeTokens = tokenMetadata.getTokens(endpoint);

            if (VersionedValue.REMOVED_TOKEN.equals(state))
            {
                excise(removeTokens, endpoint, extractExpireTime(pieces));
            }
            else if (VersionedValue.REMOVING_TOKEN.equals(state))
            {
                ensureUpToDateTokenMetadata(state, endpoint);

                if (logger.isDebugEnabled())
                    logger.debug("Tokens {} removed manually (endpoint was {})", removeTokens, endpoint);

                // Note that the endpoint is being removed
                tokenMetadata.addLeavingEndpoint(endpoint);
                PendingRangeCalculatorService.instance.update();

                // find the endpoint coordinating this removal that we need to notify when we're done
                String[] coordinator = splitValue(Gossiper.instance.getEndpointStateForEndpoint(endpoint).getApplicationState(ApplicationState.REMOVAL_COORDINATOR));
                UUID hostId = UUID.fromString(coordinator[1]);
                // grab any data we are now responsible for and notify responsible node
                restoreReplicaCount(endpoint, tokenMetadata.getEndpointForHostId(hostId));
            }
        }
        else // now that the gossiper has told us about this nonexistent member, notify the gossiper to remove it
        {
            if (VersionedValue.REMOVED_TOKEN.equals(pieces[0]))
                addExpireTimeIfFound(endpoint, extractExpireTime(pieces));
            removeEndpoint(endpoint);
        }
    }

    private void excise(Collection<Token> tokens, InetAddressAndPort endpoint)
    {
        logger.info("Removing tokens {} for {}", tokens, endpoint);

        UUID hostId = tokenMetadata.getHostId(endpoint);
        if (hostId != null && tokenMetadata.isMember(endpoint))
        {
            // enough time for writes to expire and MessagingService timeout reporter callback to fire, which is where
            // hints are mostly written from - using getMinRpcTimeout() / 2 for the interval.
            long delay = DatabaseDescriptor.getMinRpcTimeout(MILLISECONDS) + DatabaseDescriptor.getWriteRpcTimeout(MILLISECONDS);
            ScheduledExecutors.optionalTasks.schedule(() -> HintsService.instance.excise(hostId), delay, MILLISECONDS);
        }

        removeEndpoint(endpoint);
        tokenMetadata.removeEndpoint(endpoint);
        if (!tokens.isEmpty())
            tokenMetadata.removeBootstrapTokens(tokens);
        notifyLeft(endpoint);
        PendingRangeCalculatorService.instance.update();
    }

    private void excise(Collection<Token> tokens, InetAddressAndPort endpoint, long expireTime)
    {
        addExpireTimeIfFound(endpoint, expireTime);
        excise(tokens, endpoint);
    }

    /** unlike excise we just need this endpoint gone without going through any notifications **/
    private void removeEndpoint(InetAddressAndPort endpoint)
    {
        Gossiper.runInGossipStageBlocking(() -> Gossiper.instance.removeEndpoint(endpoint));
        SystemKeyspace.removeEndpoint(endpoint);
    }

    protected void addExpireTimeIfFound(InetAddressAndPort endpoint, long expireTime)
    {
        if (expireTime != 0L)
        {
            Gossiper.instance.addExpireTimeForEndpoint(endpoint, expireTime);
        }
    }

    protected long extractExpireTime(String[] pieces)
    {
        return Long.parseLong(pieces[2]);
    }

    /**
     * Finds living endpoints responsible for the given ranges
     *
     * @param keyspaceName the keyspace ranges belong to
     * @param leavingReplicas the ranges to find sources for
     * @return multimap of addresses to ranges the address is responsible for
     */
    private Multimap<InetAddressAndPort, FetchReplica> getNewSourceReplicas(String keyspaceName, Set<LeavingReplica> leavingReplicas)
    {
        InetAddressAndPort myAddress = FBUtilities.getBroadcastAddressAndPort();
        EndpointsByRange rangeReplicas = Keyspace.open(keyspaceName).getReplicationStrategy().getRangeAddresses(tokenMetadata.cloneOnlyTokenMap());
        Multimap<InetAddressAndPort, FetchReplica> sourceRanges = HashMultimap.create();
        IFailureDetector failureDetector = FailureDetector.instance;

        logger.debug("Getting new source replicas for {}", leavingReplicas);

        // find alive sources for our new ranges
        for (LeavingReplica leaver : leavingReplicas)
        {
            //We need this to find the replicas from before leaving to supply the data
            Replica leavingReplica = leaver.leavingReplica;
            //We need this to know what to fetch and what the transient status is
            Replica ourReplica = leaver.ourReplica;
            //If we are going to be a full replica only consider full replicas
            Predicate<Replica> replicaFilter = ourReplica.isFull() ? Replica::isFull : Predicates.alwaysTrue();
            Predicate<Replica> notSelf = replica -> !replica.endpoint().equals(myAddress);
            EndpointsForRange possibleReplicas = rangeReplicas.get(leavingReplica.range());
            logger.info("Possible replicas for newReplica {} are {}", ourReplica, possibleReplicas);
            IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
            EndpointsForRange sortedPossibleReplicas = snitch.sortedByProximity(myAddress, possibleReplicas);
            logger.info("Sorted possible replicas starts as {}", sortedPossibleReplicas);
            Optional<Replica> myCurrentReplica = tryFind(possibleReplicas, replica -> replica.endpoint().equals(myAddress)).toJavaUtil();

            boolean transientToFull = myCurrentReplica.isPresent() && myCurrentReplica.get().isTransient() && ourReplica.isFull();
            assert !sortedPossibleReplicas.endpoints().contains(myAddress) || transientToFull : String.format("My address %s, sortedPossibleReplicas %s, myCurrentReplica %s, myNewReplica %s", myAddress, sortedPossibleReplicas, myCurrentReplica, ourReplica);

            //Originally this didn't log if it couldn't restore replication and that seems wrong
            boolean foundLiveReplica = false;
            for (Replica possibleReplica : sortedPossibleReplicas.filter(Predicates.and(replicaFilter, notSelf)))
            {
                if (failureDetector.isAlive(possibleReplica.endpoint()))
                {
                    foundLiveReplica = true;
                    sourceRanges.put(possibleReplica.endpoint(), new FetchReplica(ourReplica, possibleReplica));
                    break;
                }
                else
                {
                    logger.debug("Skipping down replica {}", possibleReplica);
                }
            }
            if (!foundLiveReplica)
            {
                logger.warn("Didn't find live replica to restore replication for " + ourReplica);
            }
        }
        return sourceRanges;
    }

    /**
     * Sends a notification to a node indicating we have finished replicating data.
     *
     * @param remote node to send notification to
     */
    private void sendReplicationNotification(InetAddressAndPort remote)
    {
        // notify the remote token
        Message msg = Message.out(REPLICATION_DONE_REQ, noPayload);
        IFailureDetector failureDetector = FailureDetector.instance;
        if (logger.isDebugEnabled())
            logger.debug("Notifying {} of replication completion\n", remote);
        while (failureDetector.isAlive(remote))
        {
            AsyncOneResponse ior = new AsyncOneResponse();
            MessagingService.instance().sendWithCallback(msg, remote, ior);

            if (!ior.awaitUninterruptibly(DatabaseDescriptor.getRpcTimeout(NANOSECONDS), NANOSECONDS))
                continue; // try again if we timeout

            if (!ior.isSuccess())
                throw new AssertionError(ior.cause());

            return;
        }
    }

    private static class LeavingReplica
    {
        //The node that is leaving
        private final Replica leavingReplica;

        //Our range and transient status
        private final Replica ourReplica;

        public LeavingReplica(Replica leavingReplica, Replica ourReplica)
        {
            Preconditions.checkNotNull(leavingReplica);
            Preconditions.checkNotNull(ourReplica);
            this.leavingReplica = leavingReplica;
            this.ourReplica = ourReplica;
        }

        public boolean equals(Object o)
        {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;

            LeavingReplica that = (LeavingReplica) o;

            if (!leavingReplica.equals(that.leavingReplica)) return false;
            return ourReplica.equals(that.ourReplica);
        }

        public int hashCode()
        {
            int result = leavingReplica.hashCode();
            result = 31 * result + ourReplica.hashCode();
            return result;
        }

        public String toString()
        {
            return "LeavingReplica{" +
                   "leavingReplica=" + leavingReplica +
                   ", ourReplica=" + ourReplica +
                   '}';
        }
    }

    /**
     * Called when an endpoint is removed from the ring. This function checks
     * whether this node becomes responsible for new ranges as a
     * consequence and streams data if needed.
     *
     * This is rather ineffective, but it does not matter so much
     * since this is called very seldom
     *
     * @param endpoint the node that left
     */
    private void restoreReplicaCount(InetAddressAndPort endpoint, final InetAddressAndPort notifyEndpoint)
    {
        Map<String, Multimap<InetAddressAndPort, FetchReplica>> replicasToFetch = new HashMap<>();

        InetAddressAndPort myAddress = FBUtilities.getBroadcastAddressAndPort();

        for (String keyspaceName : Schema.instance.getNonLocalStrategyKeyspaces().names())
        {
            logger.debug("Restoring replica count for keyspace {}", keyspaceName);
            EndpointsByReplica changedReplicas = getChangedReplicasForLeaving(keyspaceName, endpoint, tokenMetadata, Keyspace.open(keyspaceName).getReplicationStrategy());
            Set<LeavingReplica> myNewReplicas = new HashSet<>();
            for (Map.Entry<Replica, Replica> entry : changedReplicas.flattenEntries())
            {
                Replica replica = entry.getValue();
                if (replica.endpoint().equals(myAddress))
                {
                    //Maybe we don't technically need to fetch transient data from somewhere
                    //but it's probably not a lot and it probably makes things a hair more resilient to people
                    //not running repair when they should.
                    myNewReplicas.add(new LeavingReplica(entry.getKey(), entry.getValue()));
                }
            }
            logger.debug("Changed replicas for leaving {}, myNewReplicas {}", changedReplicas, myNewReplicas);
            replicasToFetch.put(keyspaceName, getNewSourceReplicas(keyspaceName, myNewReplicas));
        }

        StreamPlan stream = new StreamPlan(StreamOperation.RESTORE_REPLICA_COUNT);
        replicasToFetch.forEach((keyspaceName, sources) -> {
            logger.debug("Requesting keyspace {} sources", keyspaceName);
            sources.asMap().forEach((sourceAddress, fetchReplicas) -> {
                logger.debug("Source and our replicas are {}", fetchReplicas);
                //Remember whether this node is providing the full or transient replicas for this range. We are going
                //to pass streaming the local instance of Replica for the range which doesn't tell us anything about the source
                //By encoding it as two separate sets we retain this information about the source.
                RangesAtEndpoint full = fetchReplicas.stream()
                                                             .filter(f -> f.remote.isFull())
                                                             .map(f -> f.local)
                                                             .collect(RangesAtEndpoint.collector(myAddress));
                RangesAtEndpoint transientReplicas = fetchReplicas.stream()
                                                                  .filter(f -> f.remote.isTransient())
                                                                  .map(f -> f.local)
                                                                  .collect(RangesAtEndpoint.collector(myAddress));
                if (logger.isDebugEnabled())
                    logger.debug("Requesting from {} full replicas {} transient replicas {}", sourceAddress, StringUtils.join(full, ", "), StringUtils.join(transientReplicas, ", "));

                stream.requestRanges(sourceAddress, keyspaceName, full, transientReplicas);
            });
        });
        StreamResultFuture future = stream.execute();
        future.addCallback(new FutureCallback<StreamState>()
        {
            public void onSuccess(StreamState finalState)
            {
                sendReplicationNotification(notifyEndpoint);
            }

            public void onFailure(Throwable t)
            {
                logger.warn("Streaming to restore replica count failed", t);
                // We still want to send the notification
                sendReplicationNotification(notifyEndpoint);
            }
        });
    }

    /**
     * This is used in three contexts, graceful decomission, and restoreReplicaCount/removeNode.
     * Graceful decomission should never lose data and it's going to be important that transient data
     * is streamed to at least one other node from this one for each range.
     *
     * For ranges this node replicates its removal should cause a new replica to be selected either as transient or full
     * for every range. So I believe the current code doesn't have to do anything special because it will engage in streaming
     * for every range it replicates to at least one other node and that should propagate the transient data that was here.
     * When I graphed this out on paper the result of removal looked correct and there are no issues such as
     * this node needing to create a full replica for a range it transiently replicates because what is created is just another
     * transient replica to replace this node.
     * @param keyspaceName
     * @param endpoint
     * @return
     */
    // needs to be modified to accept either a keyspace or ARS.
    static EndpointsByReplica getChangedReplicasForLeaving(String keyspaceName, InetAddressAndPort endpoint, TokenMetadata tokenMetadata, AbstractReplicationStrategy strat)
    {
        // First get all ranges the leaving endpoint is responsible for
        RangesAtEndpoint replicas = strat.getAddressReplicas(endpoint);

        if (logger.isDebugEnabled())
            logger.debug("Node {} replicas [{}]", endpoint, StringUtils.join(replicas, ", "));

        Map<Replica, EndpointsForRange> currentReplicaEndpoints = Maps.newHashMapWithExpectedSize(replicas.size());

        // Find (for each range) all nodes that store replicas for these ranges as well
        TokenMetadata metadata = tokenMetadata.cloneOnlyTokenMap(); // don't do this in the loop! #7758
        for (Replica replica : replicas)
            currentReplicaEndpoints.put(replica, strat.calculateNaturalReplicas(replica.range().right, metadata));

        TokenMetadata temp = tokenMetadata.cloneAfterAllLeft();

        // endpoint might or might not be 'leaving'. If it was not leaving (that is, removenode
        // command was used), it is still present in temp and must be removed.
        if (temp.isMember(endpoint))
            temp.removeEndpoint(endpoint);

        EndpointsByReplica.Builder changedRanges = new EndpointsByReplica.Builder();

        // Go through the ranges and for each range check who will be
        // storing replicas for these ranges when the leaving endpoint
        // is gone. Whoever is present in newReplicaEndpoints list, but
        // not in the currentReplicaEndpoints list, will be needing the
        // range.
        for (Replica replica : replicas)
        {
            EndpointsForRange newReplicaEndpoints = strat.calculateNaturalReplicas(replica.range().right, temp);
            newReplicaEndpoints = newReplicaEndpoints.filter(newReplica -> {
                Optional<Replica> currentReplicaOptional =
                    tryFind(currentReplicaEndpoints.get(replica),
                            currentReplica -> newReplica.endpoint().equals(currentReplica.endpoint())
                    ).toJavaUtil();
                //If it is newly replicating then yes we must do something to get the data there
                if (!currentReplicaOptional.isPresent())
                    return true;

                Replica currentReplica = currentReplicaOptional.get();
                //This transition requires streaming to occur
                //Full -> transient is handled by nodetool cleanup
                //transient -> transient and full -> full don't require any action
                if (currentReplica.isTransient() && newReplica.isFull())
                    return true;
                return false;
            });

            if (logger.isDebugEnabled())
                if (newReplicaEndpoints.isEmpty())
                    logger.debug("Replica {} already in all replicas", replica);
                else
                    logger.debug("Replica {} will be responsibility of {}", replica, StringUtils.join(newReplicaEndpoints, ", "));
            changedRanges.putAll(replica, newReplicaEndpoints, Conflict.NONE);
        }

        return changedRanges.build();
    }


    public void onJoin(InetAddressAndPort endpoint, EndpointState epState)
    {
        // Explicitly process STATUS or STATUS_WITH_PORT before the other
        // application states to maintain pre-4.0 semantics with the order
        // they are processed.  Otherwise the endpoint will not be added
        // to TokenMetadata so non-STATUS* appstates will be ignored.
        ApplicationState statusState = ApplicationState.STATUS_WITH_PORT;
        VersionedValue statusValue;
        statusValue = epState.getApplicationState(statusState);
        if (statusValue == null)
        {
            statusState = ApplicationState.STATUS;
            statusValue = epState.getApplicationState(statusState);
        }
        if (statusValue != null)
            Gossiper.instance.doOnChangeNotifications(endpoint, statusState, statusValue);

        for (Map.Entry<ApplicationState, VersionedValue> entry : epState.states())
        {
            if (entry.getKey() == ApplicationState.STATUS_WITH_PORT || entry.getKey() == ApplicationState.STATUS)
                continue;
            Gossiper.instance.doOnChangeNotifications(endpoint, entry.getKey(), entry.getValue());
        }
    }

    public void onAlive(InetAddressAndPort endpoint, EndpointState state)
    {
        if (tokenMetadata.isMember(endpoint))
            notifyUp(endpoint);
    }

    public void onRemove(InetAddressAndPort endpoint)
    {
        tokenMetadata.removeEndpoint(endpoint);
        PendingRangeCalculatorService.instance.update();
    }

    public void onDead(InetAddressAndPort endpoint, EndpointState state)
    {
        // interrupt any outbound connection; if the node is failing and we cannot reconnect,
        // this will rapidly lower the number of bytes we are willing to queue to the node
        MessagingService.instance().interruptOutbound(endpoint);
        notifyDown(endpoint);
    }

    public void onRestart(InetAddressAndPort endpoint, EndpointState state)
    {
        // If we have restarted before the node was even marked down, we need to reset the connection pool
        if (state.isAlive())
            onDead(endpoint, state);

        // Then, the node may have been upgraded and changed its messaging protocol version. If so, we
        // want to update that before we mark the node live again to avoid problems like CASSANDRA-11128.
        VersionedValue netVersion = state.getApplicationState(ApplicationState.NET_VERSION);
        if (netVersion != null)
            updateNetVersion(endpoint, netVersion);
    }

    @Override
    public String getLoadString()
    {
        return FileUtils.stringifyFileSize(StorageMetrics.load.getCount());
    }

    @Override
    public String getUncompressedLoadString()
    {
        return FileUtils.stringifyFileSize(StorageMetrics.uncompressedLoad.getCount());
    }

    public Map<String, String> getLoadMapWithPort()
    {
        return getLoadMap(true);
    }

    public Map<String, String> getLoadMap()
    {
        return getLoadMap(false);
    }

    private Map<String, String> getLoadMap(boolean withPort)
    {
        Map<String, String> map = new HashMap<>();
        for (Map.Entry<InetAddressAndPort,Double> entry : LoadBroadcaster.instance.getLoadInfo().entrySet())
        {
            map.put(entry.getKey().getHostAddress(withPort), FileUtils.stringifyFileSize(entry.getValue()));
        }
        // gossiper doesn't see its own updates, so we need to special-case the local node
        map.put(FBUtilities.getBroadcastAddressAndPort().getHostAddress(withPort), getLoadString());
        return map;
    }

    // TODO
    public final void deliverHints(String host)
    {
        throw new UnsupportedOperationException();
    }

    public Collection<Token> getLocalTokens()
    {
        Collection<Token> tokens = SystemKeyspace.getSavedTokens();
        assert tokens != null && !tokens.isEmpty(); // should not be called before initServer sets this
        return tokens;
    }

    @Nullable
    public InetAddressAndPort getEndpointForHostId(UUID hostId)
    {
        return tokenMetadata.getEndpointForHostId(hostId);
    }

    @Nullable
    public UUID getHostIdForEndpoint(InetAddressAndPort address)
    {
        return tokenMetadata.getHostId(address);
    }

    /* These methods belong to the MBean interface */

    public List<String> getTokens()
    {
        return getTokens(FBUtilities.getBroadcastAddressAndPort());
    }

    public List<String> getTokens(String endpoint) throws UnknownHostException
    {
        return getTokens(InetAddressAndPort.getByName(endpoint));
    }

    private List<String> getTokens(InetAddressAndPort endpoint)
    {
        List<String> strTokens = new ArrayList<>();
        for (Token tok : getTokenMetadata().getTokens(endpoint))
            strTokens.add(tok.toString());
        return strTokens;
    }

    public String getReleaseVersion()
    {
        return FBUtilities.getReleaseVersionString();
    }

    @Override
    public String getGitSHA()
    {
        return FBUtilities.getGitSHA();
    }

    public String getSchemaVersion()
    {
        return Schema.instance.getVersion().toString();
    }

    public String getKeyspaceReplicationInfo(String keyspaceName)
    {
        Keyspace keyspaceInstance = Schema.instance.getKeyspaceInstance(keyspaceName);
        if (keyspaceInstance == null)
            throw new IllegalArgumentException(); // ideally should never happen
        ReplicationParams replicationParams = keyspaceInstance.getMetadata().params.replication;
        String replicationInfo = replicationParams.klass.getSimpleName() + " " + replicationParams.options.toString();
        return replicationInfo;
    }

    @Deprecated
    public List<String> getLeavingNodes()
    {
        return stringify(tokenMetadata.getLeavingEndpoints(), false);
    }

    public List<String> getLeavingNodesWithPort()
    {
        return stringify(tokenMetadata.getLeavingEndpoints(), true);
    }

    @Deprecated
    public List<String> getMovingNodes()
    {
        List<String> endpoints = new ArrayList<>();

        for (Pair<Token, InetAddressAndPort> node : tokenMetadata.getMovingEndpoints())
        {
            endpoints.add(node.right.getAddress().getHostAddress());
        }

        return endpoints;
    }

    public List<String> getMovingNodesWithPort()
    {
        List<String> endpoints = new ArrayList<>();

        for (Pair<Token, InetAddressAndPort> node : tokenMetadata.getMovingEndpoints())
        {
            endpoints.add(node.right.getHostAddressAndPort());
        }

        return endpoints;
    }

    @Deprecated
    public List<String> getJoiningNodes()
    {
        return stringify(tokenMetadata.getBootstrapTokens().valueSet(), false);
    }

    public List<String> getJoiningNodesWithPort()
    {
        return stringify(tokenMetadata.getBootstrapTokens().valueSet(), true);
    }

    @Deprecated
    public List<String> getLiveNodes()
    {
        return stringify(Gossiper.instance.getLiveMembers(), false);
    }

    public List<String> getLiveNodesWithPort()
    {
        return stringify(Gossiper.instance.getLiveMembers(), true);
    }

    public Set<InetAddressAndPort> getLiveRingMembers()
    {
        return getLiveRingMembers(false);
    }

    public Set<InetAddressAndPort> getLiveRingMembers(boolean excludeDeadStates)
    {
        Set<InetAddressAndPort> ret = new HashSet<>();
        for (InetAddressAndPort ep : Gossiper.instance.getLiveMembers())
        {
            if (excludeDeadStates)
            {
                EndpointState epState = Gossiper.instance.getEndpointStateForEndpoint(ep);
                if (epState == null || Gossiper.instance.isDeadState(epState))
                    continue;
            }

            if (tokenMetadata.isMember(ep))
                ret.add(ep);
        }
        return ret;
    }


    @Deprecated
    public List<String> getUnreachableNodes()
    {
        return stringify(Gossiper.instance.getUnreachableMembers(), false);
    }

    public List<String> getUnreachableNodesWithPort()
    {
        return stringify(Gossiper.instance.getUnreachableMembers(), true);
    }

    @Override
    public String[] getAllDataFileLocations()
    {
        return getCanonicalPaths(DatabaseDescriptor.getAllDataFileLocations());
    }

    private String[] getCanonicalPaths(String[] paths)
    {
        String[] locations = new String[paths.length];
        for (int i = 0; i < paths.length; i++)
            locations[i] = FileUtils.getCanonicalPath(paths[i]);
        return locations;
    }

    @Override
    public String[] getLocalSystemKeyspacesDataFileLocations()
    {
        return getCanonicalPaths(DatabaseDescriptor.getLocalSystemKeyspacesDataFileLocations());
    }

    @Override
    public String[] getNonLocalSystemKeyspacesDataFileLocations()
    {
        return getCanonicalPaths(DatabaseDescriptor.getNonLocalSystemKeyspacesDataFileLocations());
    }

    public String getCommitLogLocation()
    {
        return FileUtils.getCanonicalPath(DatabaseDescriptor.getCommitLogLocation());
    }

    public String getSavedCachesLocation()
    {
        return FileUtils.getCanonicalPath(DatabaseDescriptor.getSavedCachesLocation());
    }

    private List<String> stringify(Iterable<InetAddressAndPort> endpoints, boolean withPort)
    {
        List<String> stringEndpoints = new ArrayList<>();
        for (InetAddressAndPort ep : endpoints)
        {
            stringEndpoints.add(ep.getHostAddress(withPort));
        }
        return stringEndpoints;
    }

    public int getCurrentGenerationNumber()
    {
        return Gossiper.instance.getCurrentGenerationNumber(FBUtilities.getBroadcastAddressAndPort());
    }

    public int forceKeyspaceCleanup(String keyspaceName, String... tables) throws IOException, ExecutionException, InterruptedException
    {
        return forceKeyspaceCleanup(0, keyspaceName, tables);
    }

    public int forceKeyspaceCleanup(int jobs, String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        if (SchemaConstants.isLocalSystemKeyspace(keyspaceName))
            throw new RuntimeException("Cleanup of the system keyspace is neither necessary nor wise");

        if (tokenMetadata.getPendingRanges(keyspaceName, getBroadcastAddressAndPort()).size() > 0)
            throw new RuntimeException("Node is involved in cluster membership changes. Not safe to run cleanup.");

        CompactionManager.AllSSTableOpStatus status = CompactionManager.AllSSTableOpStatus.SUCCESSFUL;
        logger.info("Starting {} on {}.{}", OperationType.CLEANUP, keyspaceName, Arrays.toString(tableNames));
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(false, false, keyspaceName, tableNames))
        {
            CompactionManager.AllSSTableOpStatus oneStatus = cfStore.forceCleanup(jobs);
            if (oneStatus != CompactionManager.AllSSTableOpStatus.SUCCESSFUL)
                status = oneStatus;
        }
        logger.info("Completed {} with status {}", OperationType.CLEANUP, status);
        return status.statusCode;
    }

    public int scrub(boolean disableSnapshot, boolean skipCorrupted, boolean checkData, boolean reinsertOverflowedTTL, int jobs, String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        IScrubber.Options options = IScrubber.options()
                                             .skipCorrupted(skipCorrupted)
                                             .checkData(checkData)
                                             .reinsertOverflowedTTLRows(reinsertOverflowedTTL)
                                             .build();
        return scrub(disableSnapshot, options, jobs, keyspaceName, tableNames);
    }

    public int scrub(boolean disableSnapshot, IScrubber.Options options, int jobs, String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        CompactionManager.AllSSTableOpStatus status = CompactionManager.AllSSTableOpStatus.SUCCESSFUL;
        logger.info("Starting {} on {}.{}", OperationType.SCRUB, keyspaceName, Arrays.toString(tableNames));
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(true, false, keyspaceName, tableNames))
        {
            CompactionManager.AllSSTableOpStatus oneStatus = cfStore.scrub(disableSnapshot, options, jobs);
            if (oneStatus != CompactionManager.AllSSTableOpStatus.SUCCESSFUL)
                status = oneStatus;
        }
        logger.info("Completed {} with status {}", OperationType.SCRUB, status);
        return status.statusCode;
    }

    @Deprecated
    public int verify(boolean extendedVerify, String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        return verify(extendedVerify, false, false, false, false, false, keyspaceName, tableNames);
    }

    public int verify(boolean extendedVerify, boolean checkVersion, boolean diskFailurePolicy, boolean mutateRepairStatus, boolean checkOwnsTokens, boolean quick, String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        CompactionManager.AllSSTableOpStatus status = CompactionManager.AllSSTableOpStatus.SUCCESSFUL;
        IVerifier.Options options = IVerifier.options().invokeDiskFailurePolicy(diskFailurePolicy)
                                             .extendedVerification(extendedVerify)
                                             .checkVersion(checkVersion)
                                             .mutateRepairStatus(mutateRepairStatus)
                                             .checkOwnsTokens(checkOwnsTokens)
                                             .quick(quick).build();
        logger.info("Staring {} on {}.{} with options = {}", OperationType.VERIFY, keyspaceName, Arrays.toString(tableNames), options);
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(false, false, keyspaceName, tableNames))
        {
            CompactionManager.AllSSTableOpStatus oneStatus = cfStore.verify(options);
            if (oneStatus != CompactionManager.AllSSTableOpStatus.SUCCESSFUL)
                status = oneStatus;
        }
        logger.info("Completed {} with status {}", OperationType.VERIFY, status);
        return status.statusCode;
    }

    public int upgradeSSTables(String keyspaceName, boolean excludeCurrentVersion, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        return upgradeSSTables(keyspaceName, excludeCurrentVersion, 0, tableNames);
    }

    public int upgradeSSTables(String keyspaceName,
                               final boolean skipIfCurrentVersion,
                               final long skipIfNewerThanTimestamp,
                               int jobs,
                               String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        return rewriteSSTables(keyspaceName, skipIfCurrentVersion, skipIfNewerThanTimestamp, false, jobs, tableNames);
    }

    public int recompressSSTables(String keyspaceName,
                                  int jobs,
                                  String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        return rewriteSSTables(keyspaceName, false, Long.MAX_VALUE, true, jobs, tableNames);
    }


    public int rewriteSSTables(String keyspaceName,
                               final boolean skipIfCurrentVersion,
                               final long skipIfNewerThanTimestamp,
                               final boolean skipIfCompressionMatches,
                               int jobs,
                               String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        CompactionManager.AllSSTableOpStatus status = CompactionManager.AllSSTableOpStatus.SUCCESSFUL;
        logger.info("Starting {} on {}.{}", OperationType.UPGRADE_SSTABLES, keyspaceName, Arrays.toString(tableNames));
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(true, true, keyspaceName, tableNames))
        {
            CompactionManager.AllSSTableOpStatus oneStatus = cfStore.sstablesRewrite(skipIfCurrentVersion, skipIfNewerThanTimestamp, skipIfCompressionMatches, jobs);
            if (oneStatus != CompactionManager.AllSSTableOpStatus.SUCCESSFUL)
                status = oneStatus;
        }
        logger.info("Completed {} with status {}", OperationType.UPGRADE_SSTABLES, status);
        return status.statusCode;
    }

    public List<Pair<String, String>> getPreparedStatements()
    {
        List<Pair<String, String>> statements = new ArrayList<>();
        for (Entry<MD5Digest, QueryHandler.Prepared> e : QueryProcessor.instance.getPreparedStatements().entrySet())
            statements.add(Pair.create(e.getKey().toString(), e.getValue().rawCQLStatement));
        return statements;
    }

    public void dropPreparedStatements(boolean memoryOnly)
    {
        QueryProcessor.instance.clearPreparedStatements(memoryOnly);
    }


    public void forceKeyspaceCompaction(boolean splitOutput, String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(true, false, keyspaceName, tableNames))
        {
            cfStore.forceMajorCompaction(splitOutput);
        }
    }

    public int relocateSSTables(String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        return relocateSSTables(0, keyspaceName, tableNames);
    }

    public int relocateSSTables(int jobs, String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        CompactionManager.AllSSTableOpStatus status = CompactionManager.AllSSTableOpStatus.SUCCESSFUL;
        logger.info("Starting {} on {}.{}", OperationType.RELOCATE, keyspaceName, Arrays.toString(tableNames));
        for (ColumnFamilyStore cfs : getValidColumnFamilies(false, false, keyspaceName, tableNames))
        {
            CompactionManager.AllSSTableOpStatus oneStatus = cfs.relocateSSTables(jobs);
            if (oneStatus != CompactionManager.AllSSTableOpStatus.SUCCESSFUL)
                status = oneStatus;
        }
        logger.info("Completed {} with status {}", OperationType.RELOCATE, status);
        return status.statusCode;
    }

    public int garbageCollect(String tombstoneOptionString, int jobs, String keyspaceName, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        TombstoneOption tombstoneOption = TombstoneOption.valueOf(tombstoneOptionString);
        CompactionManager.AllSSTableOpStatus status = CompactionManager.AllSSTableOpStatus.SUCCESSFUL;
        logger.info("Starting {} on {}.{}", OperationType.GARBAGE_COLLECT, keyspaceName, Arrays.toString(tableNames));
        for (ColumnFamilyStore cfs : getValidColumnFamilies(false, false, keyspaceName, tableNames))
        {
            CompactionManager.AllSSTableOpStatus oneStatus = cfs.garbageCollect(tombstoneOption, jobs);
            if (oneStatus != CompactionManager.AllSSTableOpStatus.SUCCESSFUL)
                status = oneStatus;
        }
        logger.info("Completed {} with status {}", OperationType.GARBAGE_COLLECT, status);
        return status.statusCode;
    }

    /**
     * Takes the snapshot of a multiple column family from different keyspaces. A snapshot name must be specified.
     *
     * @param tag
     *            the tag given to the snapshot; may not be null or empty
     * @param options
     *            Map of options (skipFlush is the only supported option for now)
     * @param entities
     *            list of keyspaces / tables in the form of empty | ks1 ks2 ... | ks1.cf1,ks2.cf2,...
     */
    @Override
    public void takeSnapshot(String tag, Map<String, String> options, String... entities) throws IOException
    {
        DurationSpec.IntSecondsBound ttl = options.containsKey("ttl") ? new DurationSpec.IntSecondsBound(options.get("ttl")) : null;
        if (ttl != null)
        {
            int minAllowedTtlSecs = CassandraRelevantProperties.SNAPSHOT_MIN_ALLOWED_TTL_SECONDS.getInt();
            if (ttl.toSeconds() < minAllowedTtlSecs)
                throw new IllegalArgumentException(String.format("ttl for snapshot must be at least %d seconds", minAllowedTtlSecs));
        }

        boolean skipFlush = Boolean.parseBoolean(options.getOrDefault("skipFlush", "false"));
        if (entities != null && entities.length > 0 && entities[0].contains("."))
        {
            takeMultipleTableSnapshot(tag, skipFlush, ttl, entities);
        }
        else
        {
            takeSnapshot(tag, skipFlush, ttl, entities);
        }
    }

    /**
     * Takes the snapshot of a specific table. A snapshot name must be
     * specified.
     *
     * @param keyspaceName
     *            the keyspace which holds the specified table
     * @param tableName
     *            the table to snapshot
     * @param tag
     *            the tag given to the snapshot; may not be null or empty
     */
    public void takeTableSnapshot(String keyspaceName, String tableName, String tag)
            throws IOException
    {
        takeMultipleTableSnapshot(tag, false, null, keyspaceName + "." + tableName);
    }

    @Override
    public void forceKeyspaceCompactionForTokenRange(String keyspaceName, String startToken, String endToken, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        Collection<Range<Token>> tokenRanges = createRepairRangeFrom(startToken, endToken);

        for (ColumnFamilyStore cfStore : getValidColumnFamilies(true, false, keyspaceName, tableNames))
        {
            cfStore.forceCompactionForTokenRange(tokenRanges);
        }
    }

    @Override
    public void forceKeyspaceCompactionForPartitionKey(String keyspaceName, String partitionKey, String... tableNames) throws IOException, ExecutionException, InterruptedException
    {
        // validate that the key parses before attempting compaction
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(true, false, keyspaceName, tableNames))
        {
            try
            {
                getKeyFromPartition(keyspaceName, cfStore.name, partitionKey);
            }
            catch (Exception e)
            {
                // JMX can not handle exceptions defined outside of java.* and javax.*, so safer to rewrite the exception
                IllegalArgumentException exception = new IllegalArgumentException(String.format("Unable to parse partition key '%s' for table %s; %s", partitionKey, cfStore.metadata, e.getMessage()));
                exception.setStackTrace(e.getStackTrace());
                throw exception;
            }
        }
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(true, false, keyspaceName, tableNames))
        {
            cfStore.forceCompactionForKey(getKeyFromPartition(keyspaceName, cfStore.name, partitionKey));
        }
    }

    /***
     * Forces compaction for a list of partition keys in a table
     * The method will ignore the gc_grace_seconds for the partitionKeysIgnoreGcGrace during the comapction,
     * in order to purge the tombstones and free up space quicker.
     * @param keyspaceName keyspace name
     * @param tableName table name
     * @param partitionKeysIgnoreGcGrace partition keys ignoring the gc_grace_seconds
     * @throws IOException on any I/O operation error
     * @throws ExecutionException when attempting to retrieve the result of a task that aborted by throwing an exception
     * @throws InterruptedException when a thread is waiting, sleeping, or otherwise occupied, and the thread is interrupted, either before or during the activity
     */
    public void forceCompactionKeysIgnoringGcGrace(String keyspaceName,
                                                   String tableName, String... partitionKeysIgnoreGcGrace) throws IOException, ExecutionException, InterruptedException
    {
        ColumnFamilyStore cfStore = getValidKeyspace(keyspaceName).getColumnFamilyStore(tableName);
        cfStore.forceCompactionKeysIgnoringGcGrace(partitionKeysIgnoreGcGrace);
    }

    /**
     * Takes the snapshot for the given keyspaces. A snapshot name must be specified.
     *
     * @param tag the tag given to the snapshot; may not be null or empty
     * @param keyspaceNames the names of the keyspaces to snapshot; empty means "all."
     */
    public void takeSnapshot(String tag, String... keyspaceNames) throws IOException
    {
        takeSnapshot(tag, false, null, keyspaceNames);
    }

    /**
     * Takes the snapshot of a multiple column family from different keyspaces. A snapshot name must be specified.
     *
     * @param tag
     *            the tag given to the snapshot; may not be null or empty
     * @param tableList
     *            list of tables from different keyspace in the form of ks1.cf1 ks2.cf2
     */
    public void takeMultipleTableSnapshot(String tag, String... tableList)
            throws IOException
    {
        takeMultipleTableSnapshot(tag, false, null, tableList);
    }

    /**
     * Takes the snapshot for the given keyspaces. A snapshot name must be specified.
     *
     * @param tag the tag given to the snapshot; may not be null or empty
     * @param skipFlush Skip blocking flush of memtable
     * @param keyspaceNames the names of the keyspaces to snapshot; empty means "all."
     */
    private void takeSnapshot(String tag, boolean skipFlush, DurationSpec.IntSecondsBound ttl, String... keyspaceNames) throws IOException
    {
        if (operationMode == Mode.JOINING)
            throw new IOException("Cannot snapshot until bootstrap completes");
        if (tag == null || tag.equals(""))
            throw new IOException("You must supply a snapshot name.");

        Iterable<Keyspace> keyspaces;
        if (keyspaceNames.length == 0)
        {
            keyspaces = Keyspace.all();
        }
        else
        {
            ArrayList<Keyspace> t = new ArrayList<>(keyspaceNames.length);
            for (String keyspaceName : keyspaceNames)
                t.add(getValidKeyspace(keyspaceName));
            keyspaces = t;
        }

        // Do a check to see if this snapshot exists before we actually snapshot
        for (Keyspace keyspace : keyspaces)
            if (keyspace.snapshotExists(tag))
                throw new IOException("Snapshot " + tag + " already exists.");


        RateLimiter snapshotRateLimiter = DatabaseDescriptor.getSnapshotRateLimiter();
        Instant creationTime = now();

        for (Keyspace keyspace : keyspaces)
        {
            keyspace.snapshot(tag, null, skipFlush, ttl, snapshotRateLimiter, creationTime);
        }
    }

    /**
     * Takes the snapshot of a multiple column family from different keyspaces. A snapshot name must be specified.
     *
     *
     * @param tag
     *            the tag given to the snapshot; may not be null or empty
     * @param skipFlush
     *            Skip blocking flush of memtable
     * @param tableList
     *            list of tables from different keyspace in the form of ks1.cf1 ks2.cf2
     */
    private void takeMultipleTableSnapshot(String tag, boolean skipFlush, DurationSpec.IntSecondsBound ttl, String... tableList)
            throws IOException
    {
        Map<Keyspace, List<String>> keyspaceColumnfamily = new HashMap<Keyspace, List<String>>();
        for (String table : tableList)
        {
            String splittedString[] = StringUtils.split(table, '.');
            if (splittedString.length == 2)
            {
                String keyspaceName = splittedString[0];
                String tableName = splittedString[1];

                if (keyspaceName == null)
                    throw new IOException("You must supply a keyspace name");
                if (operationMode.equals(Mode.JOINING))
                    throw new IOException("Cannot snapshot until bootstrap completes");

                if (tableName == null)
                    throw new IOException("You must supply a table name");
                if (tag == null || tag.equals(""))
                    throw new IOException("You must supply a snapshot name.");

                Keyspace keyspace = getValidKeyspace(keyspaceName);
                ColumnFamilyStore columnFamilyStore = keyspace.getColumnFamilyStore(tableName);
                // As there can be multiple column family from same keyspace check if snapshot exist for that specific
                // columnfamily and not for whole keyspace

                if (columnFamilyStore.snapshotExists(tag))
                    throw new IOException("Snapshot " + tag + " already exists.");
                if (!keyspaceColumnfamily.containsKey(keyspace))
                {
                    keyspaceColumnfamily.put(keyspace, new ArrayList<String>());
                }

                // Add Keyspace columnfamily to map in order to support atomicity for snapshot process.
                // So no snapshot should happen if any one of the above conditions fail for any keyspace or columnfamily
                keyspaceColumnfamily.get(keyspace).add(tableName);

            }
            else
            {
                throw new IllegalArgumentException(
                        "Cannot take a snapshot on secondary index or invalid column family name. You must supply a column family name in the form of keyspace.columnfamily");
            }
        }

        RateLimiter snapshotRateLimiter = DatabaseDescriptor.getSnapshotRateLimiter();
        Instant creationTime = now();

        for (Entry<Keyspace, List<String>> entry : keyspaceColumnfamily.entrySet())
        {
            for (String table : entry.getValue())
                entry.getKey().snapshot(tag, table, skipFlush, ttl, snapshotRateLimiter, creationTime);
        }
    }

    private void verifyKeyspaceIsValid(String keyspaceName)
    {
        if (null != VirtualKeyspaceRegistry.instance.getKeyspaceNullable(keyspaceName))
            throw new IllegalArgumentException("Cannot perform any operations against virtual keyspace " + keyspaceName);

        if (!Schema.instance.getKeyspaces().contains(keyspaceName))
            throw new IllegalArgumentException("Keyspace " + keyspaceName + " does not exist");
    }

    private Keyspace getValidKeyspace(String keyspaceName)
    {
        verifyKeyspaceIsValid(keyspaceName);
        return Keyspace.open(keyspaceName);
    }

    /**
     * Remove the snapshot with the given name from the given keyspaces.
     * If no tag is specified we will remove all snapshots.
     */
    public void clearSnapshot(String tag, String... keyspaceNames)
    {
        clearSnapshot(Collections.emptyMap(), tag, keyspaceNames);
    }

    public void clearSnapshot(Map<String, Object> options, String tag, String... keyspaceNames)
    {
        if (tag == null)
            tag = "";

        if (options == null)
            options = Collections.emptyMap();

        Set<String> keyspaces = new HashSet<>();
        for (String dataDir : DatabaseDescriptor.getAllDataFileLocations())
        {
            for (String keyspaceDir : new File(dataDir).tryListNames())
            {
                // Only add a ks if it has been specified as a param, assuming params were actually provided.
                if (keyspaceNames.length > 0 && !Arrays.asList(keyspaceNames).contains(keyspaceDir))
                    continue;
                keyspaces.add(keyspaceDir);
            }
        }

        Object olderThan = options.get("older_than");
        Object olderThanTimestamp = options.get("older_than_timestamp");

        final long clearOlderThanTimestamp;
        if (olderThan != null)
        {
            assert olderThan instanceof String : "it is expected that older_than is an instance of java.lang.String";
            clearOlderThanTimestamp = Clock.Global.currentTimeMillis() - new DurationSpec.LongSecondsBound((String) olderThan).toMilliseconds();
        }
        else if (olderThanTimestamp != null)
        {
            assert olderThanTimestamp instanceof String : "it is expected that older_than_timestamp is an instance of java.lang.String";
            try
            {
                clearOlderThanTimestamp = Instant.parse((String) olderThanTimestamp).toEpochMilli();
            }
            catch (DateTimeParseException ex)
            {
                throw new RuntimeException("Parameter older_than_timestamp has to be a valid instant in ISO format.");
            }
        }
        else
            clearOlderThanTimestamp = 0L;

        for (String keyspace : keyspaces)
            clearKeyspaceSnapshot(keyspace, tag, clearOlderThanTimestamp);

        if (logger.isDebugEnabled())
            logger.debug("Cleared out snapshot directories");
    }

    /**
     * Clear snapshots for a given keyspace.
     * @param keyspace keyspace to remove snapshots for
     * @param tag the user supplied snapshot name. If empty or null, all the snapshots will be cleaned
     * @param olderThanTimestamp if a snapshot was created before this timestamp, it will be cleared,
     *                           if its value is 0, this parameter is effectively ignored.
     */
    private void clearKeyspaceSnapshot(String keyspace, String tag, long olderThanTimestamp)
    {
        Set<TableSnapshot> snapshotsToClear = snapshotManager.loadSnapshots(keyspace)
                                                             .stream()
                                                             .filter(TableSnapshot.shouldClearSnapshot(tag, olderThanTimestamp))
                                                             .collect(Collectors.toSet());
        for (TableSnapshot snapshot : snapshotsToClear)
            snapshotManager.clearSnapshot(snapshot);
    }

    public Map<String, TabularData> getSnapshotDetails(Map<String, String> options)
    {
        boolean skipExpiring = options != null && Boolean.parseBoolean(options.getOrDefault("no_ttl", "false"));
        boolean includeEphemeral = options != null && Boolean.parseBoolean(options.getOrDefault("include_ephemeral", "false"));

        Map<String, TabularData> snapshotMap = new HashMap<>();

        for (TableSnapshot snapshot : snapshotManager.loadSnapshots())
        {
            if (skipExpiring && snapshot.isExpiring())
                continue;
            if (!includeEphemeral && snapshot.isEphemeral())
                continue;

            TabularDataSupport data = (TabularDataSupport) snapshotMap.get(snapshot.getTag());
            if (data == null)
            {
                data = new TabularDataSupport(SnapshotDetailsTabularData.TABULAR_TYPE);
                snapshotMap.put(snapshot.getTag(), data);
            }

            SnapshotDetailsTabularData.from(snapshot, data);
        }

        return snapshotMap;
    }

    @Deprecated
    public Map<String, TabularData> getSnapshotDetails()
    {
        return getSnapshotDetails(ImmutableMap.of());
    }

    public long trueSnapshotsSize()
    {
        long total = 0;
        for (Keyspace keyspace : Keyspace.all())
        {
            if (SchemaConstants.isLocalSystemKeyspace(keyspace.getName()))
                continue;

            for (ColumnFamilyStore cfStore : keyspace.getColumnFamilyStores())
            {
                total += cfStore.trueSnapshotsSize();
            }
        }

        return total;
    }

    public void setSnapshotLinksPerSecond(long throttle)
    {
        logger.info("Setting snapshot throttle to {}", throttle);
        DatabaseDescriptor.setSnapshotLinksPerSecond(throttle);
    }

    public long getSnapshotLinksPerSecond()
    {
        return DatabaseDescriptor.getSnapshotLinksPerSecond();
    }

    public void refreshSizeEstimates() throws ExecutionException
    {
        cleanupSizeEstimates();
        FBUtilities.waitOnFuture(ScheduledExecutors.optionalTasks.submit(SizeEstimatesRecorder.instance));
    }

    public void cleanupSizeEstimates()
    {
        SystemKeyspace.clearAllEstimates();
    }

    /**
     * @param allowIndexes Allow index CF names to be passed in
     * @param autoAddIndexes Automatically add secondary indexes if a CF has them
     * @param keyspaceName keyspace
     * @param cfNames CFs
     * @throws java.lang.IllegalArgumentException when given CF name does not exist
     */
    public Iterable<ColumnFamilyStore> getValidColumnFamilies(boolean allowIndexes, boolean autoAddIndexes, String keyspaceName, String... cfNames) throws IOException
    {
        Keyspace keyspace = getValidKeyspace(keyspaceName);
        return keyspace.getValidColumnFamilies(allowIndexes, autoAddIndexes, cfNames);
    }

    /**
     * Flush all memtables for a keyspace and column families.
     * @param keyspaceName
     * @param tableNames
     * @throws IOException
     */
    public void forceKeyspaceFlush(String keyspaceName, String... tableNames) throws IOException
    {
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(true, false, keyspaceName, tableNames))
        {
            logger.debug("Forcing flush on keyspace {}, CF {}", keyspaceName, cfStore.name);
            cfStore.forceBlockingFlush(ColumnFamilyStore.FlushReason.USER_FORCED);
        }
    }

    /**
     * Flush all memtables for a keyspace and column families.
     * @param keyspaceName
     * @throws IOException
     */
    public void forceKeyspaceFlush(String keyspaceName, ColumnFamilyStore.FlushReason reason) throws IOException
    {
        for (ColumnFamilyStore cfStore : getValidColumnFamilies(true, false, keyspaceName))
        {
            logger.debug("Forcing flush on keyspace {}, CF {}", keyspaceName, cfStore.name);
            cfStore.forceBlockingFlush(reason);
        }
    }

    public int repairAsync(String keyspace, Map<String, String> repairSpec)
    {
        return repair(keyspace, repairSpec, Collections.emptyList()).left;
    }

    public Pair<Integer, Future<?>> repair(String keyspace, Map<String, String> repairSpec, List<ProgressListener> listeners)
    {
        RepairOption option = RepairOption.parse(repairSpec, tokenMetadata.partitioner);
        return repair(keyspace, option, listeners);
    }

    public Pair<Integer, Future<?>> repair(String keyspace, RepairOption option, List<ProgressListener> listeners)
    {
        // if ranges are not specified
        if (option.getRanges().isEmpty())
        {
            if (option.isPrimaryRange())
            {
                // when repairing only primary range, neither dataCenters nor hosts can be set
                if (option.getDataCenters().isEmpty() && option.getHosts().isEmpty())
                    option.getRanges().addAll(getPrimaryRanges(keyspace));
                    // except dataCenters only contain local DC (i.e. -local)
                else if (option.isInLocalDCOnly())
                    option.getRanges().addAll(getPrimaryRangesWithinDC(keyspace));
                else
                    throw new IllegalArgumentException("You need to run primary range repair on all nodes in the cluster.");
            }
            else
            {
                Iterables.addAll(option.getRanges(), getLocalReplicas(keyspace).onlyFull().ranges());
            }
        }
        if (option.getRanges().isEmpty() || Keyspace.open(keyspace).getReplicationStrategy().getReplicationFactor().allReplicas < 2)
            return Pair.create(0, ImmediateFuture.success(null));

        int cmd = nextRepairCommand.incrementAndGet();
        return Pair.create(cmd, repairCommandExecutor().submit(createRepairTask(cmd, keyspace, option, listeners)));
    }

    /**
     * Create collection of ranges that match ring layout from given tokens.
     *
     * @param beginToken beginning token of the range
     * @param endToken end token of the range
     * @return collection of ranges that match ring layout in TokenMetadata
     */
    @VisibleForTesting
    Collection<Range<Token>> createRepairRangeFrom(String beginToken, String endToken)
    {
        Token parsedBeginToken = getTokenFactory().fromString(beginToken);
        Token parsedEndToken = getTokenFactory().fromString(endToken);

        // Break up given range to match ring layout in TokenMetadata
        ArrayList<Range<Token>> repairingRange = new ArrayList<>();

        ArrayList<Token> tokens = new ArrayList<>(tokenMetadata.sortedTokens());
        if (!tokens.contains(parsedBeginToken))
        {
            tokens.add(parsedBeginToken);
        }
        if (!tokens.contains(parsedEndToken))
        {
            tokens.add(parsedEndToken);
        }
        // tokens now contain all tokens including our endpoints
        Collections.sort(tokens);

        int start = tokens.indexOf(parsedBeginToken), end = tokens.indexOf(parsedEndToken);
        for (int i = start; i != end; i = (i+1) % tokens.size())
        {
            Range<Token> range = new Range<>(tokens.get(i), tokens.get((i+1) % tokens.size()));
            repairingRange.add(range);
        }

        return repairingRange;
    }

    public TokenFactory getTokenFactory()
    {
        return tokenMetadata.partitioner.getTokenFactory();
    }

    private FutureTask<Object> createRepairTask(final int cmd, final String keyspace, final RepairOption options, List<ProgressListener> listeners)
    {
        if (!options.getDataCenters().isEmpty() && !options.getDataCenters().contains(DatabaseDescriptor.getLocalDataCenter()))
        {
            throw new IllegalArgumentException("the local data center must be part of the repair");
        }
        Set<String> existingDatacenters = tokenMetadata.cloneOnlyTokenMap().getTopology().getDatacenterEndpoints().keys().elementSet();
        List<String> datacenters = new ArrayList<>(options.getDataCenters());
        if (!existingDatacenters.containsAll(datacenters))
        {
            datacenters.removeAll(existingDatacenters);
            throw new IllegalArgumentException("data center(s) " + datacenters.toString() + " not found");
        }

        RepairRunnable task = new RepairRunnable(this, cmd, options, keyspace);
        task.addProgressListener(progressSupport);
        for (ProgressListener listener : listeners)
            task.addProgressListener(listener);

        if (options.isTraced())
            return new FutureTaskWithResources<>(() -> ExecutorLocals::clear, task);
        return new FutureTask<>(task);
    }

    private void tryRepairPaxosForTopologyChange(String reason)
    {
        try
        {
            startRepairPaxosForTopologyChange(reason).get();
        }
        catch (InterruptedException e)
        {
            logger.error("Error during paxos repair", e);
            throw new AssertionError(e);
        }
        catch (ExecutionException e)
        {
            logger.error("Error during paxos repair", e);
            throw new RuntimeException(e);
        }
    }

    private void repairPaxosForTopologyChange(String reason)
    {
        if (getSkipPaxosRepairOnTopologyChange() || !Paxos.useV2())
        {
            logger.info("skipping paxos repair for {}. skip_paxos_repair_on_topology_change is set, or v2 paxos variant is not being used", reason);
            return;
        }

        logger.info("repairing paxos for {}", reason);

        int retries = 0;
        int maxRetries = PAXOS_REPAIR_ON_TOPOLOGY_CHANGE_RETRIES.getInt();
        int delaySec = PAXOS_REPAIR_ON_TOPOLOGY_CHANGE_RETRY_DELAY_SECONDS.getInt();

        boolean completed = false;
        while (!completed)
        {
            try
            {
                tryRepairPaxosForTopologyChange(reason);
                completed = true;
            }
            catch (Exception e)
            {
                if (retries >= maxRetries)
                    throw e;

                retries++;
                int sleep = delaySec * retries;
                logger.info("Sleeping {} seconds before retrying paxos repair...", sleep);
                Uninterruptibles.sleepUninterruptibly(sleep, TimeUnit.SECONDS);
                logger.info("Retrying paxos repair for {}. Retry {}/{}", reason, retries, maxRetries);
            }
        }

        logger.info("paxos repair for {} complete", reason);
    }

    @VisibleForTesting
    public Future<?> startRepairPaxosForTopologyChange(String reason)
    {
        logger.info("repairing paxos for {}", reason);

        List<Future<?>> futures = new ArrayList<>();

        Keyspaces keyspaces = Schema.instance.getNonLocalStrategyKeyspaces();
        for (String ksName : keyspaces.names())
        {
            if (SchemaConstants.REPLICATED_SYSTEM_KEYSPACE_NAMES.contains(ksName))
                continue;

            if (DatabaseDescriptor.skipPaxosRepairOnTopologyChangeKeyspaces().contains(ksName))
                continue;

            List<Range<Token>> ranges = getLocalAndPendingRanges(ksName);
            futures.add(ActiveRepairService.instance.repairPaxosForTopologyChange(ksName, ranges, reason));
        }

        return FutureCombiner.allOf(futures);
    }

    public Future<?> autoRepairPaxos(TableId tableId)
    {
        TableMetadata table = Schema.instance.getTableMetadata(tableId);
        if (table == null)
            return ImmediateFuture.success(null);

        List<Range<Token>> ranges = getLocalAndPendingRanges(table.keyspace);
        PaxosCleanupLocalCoordinator coordinator = PaxosCleanupLocalCoordinator.createForAutoRepair(tableId, ranges);
        ScheduledExecutors.optionalTasks.submit(coordinator::start);
        return coordinator;
    }

    public void forceTerminateAllRepairSessions()
    {
        ActiveRepairService.instance.terminateSessions();
    }

    @Nullable
    public List<String> getParentRepairStatus(int cmd)
    {
        Pair<ParentRepairStatus, List<String>> pair = ActiveRepairService.instance.getRepairStatus(cmd);
        return pair == null ? null :
               ImmutableList.<String>builder().add(pair.left.name()).addAll(pair.right).build();
    }

    @Deprecated
    @Override
    public void setRepairSessionMaxTreeDepth(int depth)
    {
        DatabaseDescriptor.setRepairSessionMaxTreeDepth(depth);
    }

    @Deprecated
    @Override
    public int getRepairSessionMaxTreeDepth()
    {
        return DatabaseDescriptor.getRepairSessionMaxTreeDepth();
    }

    @Override
    public void setRepairSessionMaximumTreeDepth(int depth)
    {
        try
        {
            DatabaseDescriptor.setRepairSessionMaxTreeDepth(depth);
        }
        catch (ConfigurationException e)
        {
            throw new IllegalArgumentException(e.getMessage());
        }
    }

    /*
     * In CASSANDRA-17668, JMX setters that did not throw standard exceptions were deprecated in favor of ones that do.
     * For consistency purposes, the respective getter "getRepairSessionMaxTreeDepth" was also deprecated and replaced
     * by this method.
     */
    @Override
    public int getRepairSessionMaximumTreeDepth()
    {
        return DatabaseDescriptor.getRepairSessionMaxTreeDepth();
    }

    /* End of MBean interface methods */

    /**
     * Get the "primary ranges" for the specified keyspace and endpoint.
     * "Primary ranges" are the ranges that the node is responsible for storing replica primarily.
     * The node that stores replica primarily is defined as the first node returned
     * by {@link AbstractReplicationStrategy#calculateNaturalReplicas}.
     *
     * @param keyspace Keyspace name to check primary ranges
     * @param ep endpoint we are interested in.
     * @return primary ranges for the specified endpoint.
     */
    public Collection<Range<Token>> getPrimaryRangesForEndpoint(String keyspace, InetAddressAndPort ep)
    {
        AbstractReplicationStrategy strategy = Keyspace.open(keyspace).getReplicationStrategy();
        Collection<Range<Token>> primaryRanges = new HashSet<>();
        TokenMetadata metadata = tokenMetadata.cloneOnlyTokenMap();
        for (Token token : metadata.sortedTokens())
        {
            EndpointsForRange replicas = strategy.calculateNaturalReplicas(token, metadata);
            if (replicas.size() > 0 && replicas.get(0).endpoint().equals(ep))
            {
                Preconditions.checkState(replicas.get(0).isFull());
                primaryRanges.add(new Range<>(metadata.getPredecessor(token), token));
            }
        }
        return primaryRanges;
    }

    /**
     * Get the "primary ranges" within local DC for the specified keyspace and endpoint.
     *
     * @see #getPrimaryRangesForEndpoint(String, InetAddressAndPort)
     * @param keyspace Keyspace name to check primary ranges
     * @param referenceEndpoint endpoint we are interested in.
     * @return primary ranges within local DC for the specified endpoint.
     */
    public Collection<Range<Token>> getPrimaryRangeForEndpointWithinDC(String keyspace, InetAddressAndPort referenceEndpoint)
    {
        TokenMetadata metadata = tokenMetadata.cloneOnlyTokenMap();
        String localDC = DatabaseDescriptor.getEndpointSnitch().getDatacenter(referenceEndpoint);
        Collection<InetAddressAndPort> localDcNodes = metadata.getTopology().getDatacenterEndpoints().get(localDC);
        AbstractReplicationStrategy strategy = Keyspace.open(keyspace).getReplicationStrategy();

        Collection<Range<Token>> localDCPrimaryRanges = new HashSet<>();
        for (Token token : metadata.sortedTokens())
        {
            EndpointsForRange replicas = strategy.calculateNaturalReplicas(token, metadata);
            for (Replica replica : replicas)
            {
                if (localDcNodes.contains(replica.endpoint()))
                {
                    if (replica.endpoint().equals(referenceEndpoint))
                    {
                        localDCPrimaryRanges.add(new Range<>(metadata.getPredecessor(token), token));
                    }
                    break;
                }
            }
        }

        return localDCPrimaryRanges;
    }

    public Collection<Range<Token>> getLocalPrimaryRange()
    {
        return getLocalPrimaryRangeForEndpoint(FBUtilities.getBroadcastAddressAndPort());
    }

    public Collection<Range<Token>> getLocalPrimaryRangeForEndpoint(InetAddressAndPort referenceEndpoint)
    {
        IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
        TokenMetadata tokenMetadata = this.tokenMetadata.cloneOnlyTokenMap();
        if (!tokenMetadata.isMember(referenceEndpoint))
            return Collections.emptySet();
        String dc = snitch.getDatacenter(referenceEndpoint);
        Set<Token> tokens = new HashSet<>(tokenMetadata.getTokens(referenceEndpoint));

        // filter tokens to the single DC
        List<Token> filteredTokens = Lists.newArrayList();
        for (Token token : tokenMetadata.sortedTokens())
        {
            InetAddressAndPort endpoint = tokenMetadata.getEndpoint(token);
            if (dc.equals(snitch.getDatacenter(endpoint)))
                filteredTokens.add(token);
        }

        return getAllRanges(filteredTokens).stream()
                                           .filter(t -> tokens.contains(t.right))
                                           .collect(Collectors.toList());
    }

    /**
     * Get all ranges that span the ring given a set
     * of tokens. All ranges are in sorted order of
     * ranges.
     * @return ranges in sorted order
    */
    public List<Range<Token>> getAllRanges(List<Token> sortedTokens)
    {
        if (logger.isTraceEnabled())
            logger.trace("computing ranges for {}", StringUtils.join(sortedTokens, ", "));

        if (sortedTokens.isEmpty())
            return Collections.emptyList();
        int size = sortedTokens.size();
        List<Range<Token>> ranges = new ArrayList<>(size + 1);
        for (int i = 1; i < size; ++i)
        {
            Range<Token> range = new Range<>(sortedTokens.get(i - 1), sortedTokens.get(i));
            ranges.add(range);
        }
        Range<Token> range = new Range<>(sortedTokens.get(size - 1), sortedTokens.get(0));
        ranges.add(range);

        return ranges;
    }

    /**
     * This method returns the N endpoints that are responsible for storing the
     * specified key i.e for replication.
     *
     * @param keyspaceName keyspace name also known as keyspace
     * @param cf Column family name
     * @param key key for which we need to find the endpoint
     * @return the endpoint responsible for this key
     */
    @Deprecated
    public List<InetAddress> getNaturalEndpoints(String keyspaceName, String cf, String key)
    {
        EndpointsForToken replicas = getNaturalReplicasForToken(keyspaceName, cf, key);
        List<InetAddress> inetList = new ArrayList<>(replicas.size());
        replicas.forEach(r -> inetList.add(r.endpoint().getAddress()));
        return inetList;
    }

    public List<String> getNaturalEndpointsWithPort(String keyspaceName, String cf, String key)
    {
        return Replicas.stringify(getNaturalReplicasForToken(keyspaceName, cf, key), true);
    }

    @Deprecated
    public List<InetAddress> getNaturalEndpoints(String keyspaceName, ByteBuffer key)
    {
        EndpointsForToken replicas = getNaturalReplicasForToken(keyspaceName, key);
        List<InetAddress> inetList = new ArrayList<>(replicas.size());
        replicas.forEach(r -> inetList.add(r.endpoint().getAddress()));
        return inetList;
    }

    public List<String> getNaturalEndpointsWithPort(String keyspaceName, ByteBuffer key)
    {
        EndpointsForToken replicas = getNaturalReplicasForToken(keyspaceName, key);
        return Replicas.stringify(replicas, true);
    }

    public EndpointsForToken getNaturalReplicasForToken(String keyspaceName, String cf, String key)
    {
        return getNaturalReplicasForToken(keyspaceName, partitionKeyToBytes(keyspaceName, cf, key));
    }

    public EndpointsForToken getNaturalReplicasForToken(String keyspaceName, ByteBuffer key)
    {
        Token token = tokenMetadata.partitioner.getToken(key);
        return Keyspace.open(keyspaceName).getReplicationStrategy().getNaturalReplicasForToken(token);
    }

    public DecoratedKey getKeyFromPartition(String keyspaceName, String table, String partitionKey)
    {
        return tokenMetadata.partitioner.decorateKey(partitionKeyToBytes(keyspaceName, table, partitionKey));
    }

    private static ByteBuffer partitionKeyToBytes(String keyspaceName, String cf, String key)
    {
        KeyspaceMetadata ksMetaData = Schema.instance.getKeyspaceMetadata(keyspaceName);
        if (ksMetaData == null)
            throw new IllegalArgumentException("Unknown keyspace '" + keyspaceName + "'");

        TableMetadata metadata = ksMetaData.getTableOrViewNullable(cf);
        if (metadata == null)
            throw new IllegalArgumentException("Unknown table '" + cf + "' in keyspace '" + keyspaceName + "'");

        return metadata.partitionKeyType.fromString(key);
    }

    @Override
    public String getToken(String keyspaceName, String table, String key)
    {
        return tokenMetadata.partitioner.getToken(partitionKeyToBytes(keyspaceName, table, key)).toString();
    }

    public void setLoggingLevel(String classQualifier, String rawLevel) throws Exception
    {
        LoggingSupportFactory.getLoggingSupport().setLoggingLevel(classQualifier, rawLevel);
    }

    /**
     * @return the runtime logging levels for all the configured loggers
     */
    @Override
    public Map<String,String> getLoggingLevels()
    {
        return LoggingSupportFactory.getLoggingSupport().getLoggingLevels();
    }

    /**
     * @return list of Token ranges (_not_ keys!) together with estimated key count,
     *      breaking up the data this node is responsible for into pieces of roughly keysPerSplit
     */
    public List<Pair<Range<Token>, Long>> getSplits(String keyspaceName, String cfName, Range<Token> range, int keysPerSplit)
    {
        Keyspace t = Keyspace.open(keyspaceName);
        ColumnFamilyStore cfs = t.getColumnFamilyStore(cfName);
        List<DecoratedKey> keys = keySamples(Collections.singleton(cfs), range);

        long totalRowCountEstimate = cfs.estimatedKeysForRange(range);

        // splitCount should be much smaller than number of key samples, to avoid huge sampling error
        int minSamplesPerSplit = 4;
        int maxSplitCount = keys.size() / minSamplesPerSplit + 1;
        int splitCount = Math.max(1, Math.min(maxSplitCount, (int)(totalRowCountEstimate / keysPerSplit)));

        List<Token> tokens = keysToTokens(range, keys);
        return getSplits(tokens, splitCount, cfs);
    }

    private List<Pair<Range<Token>, Long>> getSplits(List<Token> tokens, int splitCount, ColumnFamilyStore cfs)
    {
        double step = (double) (tokens.size() - 1) / splitCount;
        Token prevToken = tokens.get(0);
        List<Pair<Range<Token>, Long>> splits = Lists.newArrayListWithExpectedSize(splitCount);
        for (int i = 1; i <= splitCount; i++)
        {
            int index = (int) Math.round(i * step);
            Token token = tokens.get(index);
            Range<Token> range = new Range<>(prevToken, token);
            // always return an estimate > 0 (see CASSANDRA-7322)
            splits.add(Pair.create(range, Math.max(cfs.metadata().params.minIndexInterval, cfs.estimatedKeysForRange(range))));
            prevToken = token;
        }
        return splits;
    }

    private List<Token> keysToTokens(Range<Token> range, List<DecoratedKey> keys)
    {
        List<Token> tokens = Lists.newArrayListWithExpectedSize(keys.size() + 2);
        tokens.add(range.left);
        for (DecoratedKey key : keys)
            tokens.add(key.getToken());
        tokens.add(range.right);
        return tokens;
    }

    private List<DecoratedKey> keySamples(Iterable<ColumnFamilyStore> cfses, Range<Token> range)
    {
        List<DecoratedKey> keys = new ArrayList<>();
        for (ColumnFamilyStore cfs : cfses)
            Iterables.addAll(keys, cfs.keySamples(range));
        FBUtilities.sortSampledKeys(keys, range);
        return keys;
    }

    /**
     * Broadcast leaving status and update local tokenMetadata accordingly
     */
    private void startLeaving()
    {
        DatabaseDescriptor.getSeverityDuringDecommission().ifPresent(DynamicEndpointSnitch::addSeverity);
        Gossiper.instance.addLocalApplicationState(ApplicationState.STATUS_WITH_PORT, valueFactory.leaving(getLocalTokens()));
        Gossiper.instance.addLocalApplicationState(ApplicationState.STATUS, valueFactory.leaving(getLocalTokens()));
        tokenMetadata.addLeavingEndpoint(FBUtilities.getBroadcastAddressAndPort());
        PendingRangeCalculatorService.instance.update();
    }

    public void decommission(boolean force) throws InterruptedException
    {
        if (operationMode == DECOMMISSIONED)
        {
            logger.info("This node was already decommissioned. There is no point in decommissioning it again.");
            return;
        }

        if (isDecommissioning())
        {
            logger.info("This node is still decommissioning.");
            return;
        }

        TokenMetadata metadata = tokenMetadata.cloneAfterAllLeft();
        // there is no point to do this logic again once node was decommissioning but failed to do so
        if (operationMode != Mode.LEAVING)
        {
            if (!tokenMetadata.isMember(FBUtilities.getBroadcastAddressAndPort()))
                throw new UnsupportedOperationException("local node is not a member of the token ring yet");
            if (metadata.getAllEndpoints().size() < 2 && metadata.getAllEndpoints().contains(FBUtilities.getBroadcastAddressAndPort()))
                    throw new UnsupportedOperationException("no other normal nodes in the ring; decommission would be pointless");
            if (operationMode != Mode.NORMAL && operationMode != DECOMMISSION_FAILED)
                throw new UnsupportedOperationException("Node in " + operationMode + " state; wait for status to become normal or restart");
        }

        if (!isDecommissioning.compareAndSet(false, true))
            throw new IllegalStateException("Node is still decommissioning. Check nodetool netstats or nodetool info.");

        if (logger.isDebugEnabled())
            logger.debug("DECOMMISSIONING");

        try
        {
            PendingRangeCalculatorService.instance.blockUntilFinished();

            String dc = DatabaseDescriptor.getEndpointSnitch().getLocalDatacenter();

            // If we're already decommissioning there is no point checking RF/pending ranges
            if (operationMode != Mode.LEAVING)
            {
                int rf, numNodes;
                for (String keyspaceName : Schema.instance.getNonLocalStrategyKeyspaces().names())
                {
                    if (!force)
                    {
                        boolean notEnoughLiveNodes = false;
                        Keyspace keyspace = Keyspace.open(keyspaceName);
                        if (keyspace.getReplicationStrategy() instanceof NetworkTopologyStrategy)
                        {
                            NetworkTopologyStrategy strategy = (NetworkTopologyStrategy) keyspace.getReplicationStrategy();
                            rf = strategy.getReplicationFactor(dc).allReplicas;
                            Collection<InetAddressAndPort> datacenterEndpoints = metadata.getTopology().getDatacenterEndpoints().get(dc);
                            numNodes = datacenterEndpoints.size();
                            if (numNodes <= rf && datacenterEndpoints.contains(FBUtilities.getBroadcastAddressAndPort()))
                                notEnoughLiveNodes = true;
                        }
                        else
                        {
                            Set<InetAddressAndPort> allEndpoints = metadata.getAllEndpoints();
                            numNodes = allEndpoints.size();
                            rf = keyspace.getReplicationStrategy().getReplicationFactor().allReplicas;
                            if (numNodes <= rf && allEndpoints.contains(FBUtilities.getBroadcastAddressAndPort()))
                                notEnoughLiveNodes = true;
                        }

                        if (notEnoughLiveNodes)
                            throw new UnsupportedOperationException("Not enough live nodes to maintain replication factor in keyspace "
                                                                    + keyspaceName + " (RF = " + rf + ", N = " + numNodes + ")."
                                                                    + " Perform a forceful decommission to ignore.");
                    }
                    // TODO: do we care about fixing transient/full self-movements here? probably
                    if (tokenMetadata.getPendingRanges(keyspaceName, FBUtilities.getBroadcastAddressAndPort()).size() > 0)
                        throw new UnsupportedOperationException("data is currently moving to this node; unable to leave the ring");
                }
            }

            startLeaving();
            long timeout = Math.max(RING_DELAY_MILLIS, BatchlogManager.getBatchlogTimeout());
            setMode(Mode.LEAVING, "sleeping " + timeout + " ms for batch processing and pending range setup", true);
            Thread.sleep(timeout);

            unbootstrap();

            // shutdown cql, gossip, messaging, Stage and set state to DECOMMISSIONED

            shutdownClientServers();
            Gossiper.instance.stop();
            try
            {
                MessagingService.instance().shutdown();
            }
            catch (IOError ioe)
            {
                logger.info("failed to shutdown message service", ioe);
            }

            Stage.shutdownNow();
            SystemKeyspace.setBootstrapState(SystemKeyspace.BootstrapState.DECOMMISSIONED);
            setMode(DECOMMISSIONED, true);
            // let op be responsible for killing the process
        }
        catch (InterruptedException e)
        {
            setMode(DECOMMISSION_FAILED, true);
            logger.error("Node interrupted while decommissioning");
            throw new RuntimeException("Node interrupted while decommissioning");
        }
        catch (ExecutionException e)
        {
            setMode(DECOMMISSION_FAILED, true);
            logger.error("Error while decommissioning node: {}", e.getCause().getMessage());
            throw new RuntimeException("Error while decommissioning node: " + e.getCause().getMessage());
        }
        catch (Throwable t)
        {
            setMode(DECOMMISSION_FAILED, true);
            logger.error("Error while decommissioning node: {}", t.getMessage());
            throw t;
        }
        finally
        {
            isDecommissioning.set(false);
        }
    }

    private void leaveRing()
    {
        SystemKeyspace.setBootstrapState(SystemKeyspace.BootstrapState.NEEDS_BOOTSTRAP);
        tokenMetadata.removeEndpoint(FBUtilities.getBroadcastAddressAndPort());
        PendingRangeCalculatorService.instance.update();

        Gossiper.instance.addLocalApplicationState(ApplicationState.STATUS_WITH_PORT, valueFactory.left(getLocalTokens(),Gossiper.computeExpireTime()));
        Gossiper.instance.addLocalApplicationState(ApplicationState.STATUS, valueFactory.left(getLocalTokens(),Gossiper.computeExpireTime()));
        int delay = Math.max(RING_DELAY_MILLIS, Gossiper.intervalInMillis * 2);
        logger.info("Announcing that I have left the ring for {}ms", delay);
        Uninterruptibles.sleepUninterruptibly(delay, MILLISECONDS);
    }

    public Supplier<Future<StreamState>> prepareUnbootstrapStreaming()
    {
        Map<String, EndpointsByReplica> rangesToStream = new HashMap<>();

        for (String keyspaceName : Schema.instance.getNonLocalStrategyKeyspaces().names())
        {
            EndpointsByReplica rangesMM = getChangedReplicasForLeaving(keyspaceName, FBUtilities.getBroadcastAddressAndPort(), tokenMetadata, Keyspace.open(keyspaceName).getReplicationStrategy());

            if (logger.isDebugEnabled())
                logger.debug("Ranges needing transfer are [{}]", StringUtils.join(rangesMM.keySet(), ","));

            rangesToStream.put(keyspaceName, rangesMM);
        }

        return () -> streamRanges(rangesToStream);
    }

    private void unbootstrap() throws ExecutionException, InterruptedException
    {
        Supplier<Future<StreamState>> startStreaming = prepareUnbootstrapStreaming();

        setMode(Mode.LEAVING, "replaying batch log and streaming data to other nodes", true);

        repairPaxosForTopologyChange("decommission");
        // Start with BatchLog replay, which may create hints but no writes since this is no longer a valid endpoint.
        Future<?> batchlogReplay = BatchlogManager.instance.startBatchlogReplay();
        Future<StreamState> streamSuccess = startStreaming.get();

        // Wait for batch log to complete before streaming hints.
        logger.debug("waiting for batch log processing.");
        batchlogReplay.get();

        Future<?> hintsSuccess = ImmediateFuture.success(null);

        if (DatabaseDescriptor.getTransferHintsOnDecommission()) 
        {
            setMode(Mode.LEAVING, "streaming hints to other nodes", true);
            hintsSuccess = streamHints();
        }
        else
        {
            setMode(Mode.LEAVING, "pausing dispatch and deleting hints", true);
            DatabaseDescriptor.setHintedHandoffEnabled(false);
            HintsService.instance.pauseDispatch();
            HintsService.instance.deleteAllHints();
        }

        // wait for the transfer runnables to signal the latch.
        logger.debug("waiting for stream acks.");
        streamSuccess.get();
        hintsSuccess.get();
        logger.debug("stream acks all received.");
        leaveRing();
    }

    private Future streamHints()
    {
        return HintsService.instance.transferHints(this::getPreferredHintsStreamTarget);
    }

    private static EndpointsForRange getStreamCandidates(Collection<InetAddressAndPort> endpoints)
    {
        endpoints = endpoints.stream()
                             .filter(endpoint -> FailureDetector.instance.isAlive(endpoint) && !FBUtilities.getBroadcastAddressAndPort().equals(endpoint))
                             .collect(Collectors.toList());

        return SystemReplicas.getSystemReplicas(endpoints);
    }
    /**
     * Find the best target to stream hints to. Currently the closest peer according to the snitch
     */
    private UUID getPreferredHintsStreamTarget()
    {
        Set<InetAddressAndPort> endpoints = StorageService.instance.getTokenMetadata().cloneAfterAllLeft().getAllEndpoints();

        EndpointsForRange candidates = getStreamCandidates(endpoints);
        if (candidates.isEmpty())
        {
            logger.warn("Unable to stream hints since no live endpoints seen");
            throw new RuntimeException("Unable to stream hints since no live endpoints seen");
        }
        else
        {
            // stream to the closest peer as chosen by the snitch
            candidates = DatabaseDescriptor.getEndpointSnitch().sortedByProximity(FBUtilities.getBroadcastAddressAndPort(), candidates);
            InetAddressAndPort hintsDestinationHost = candidates.get(0).endpoint();
            return tokenMetadata.getHostId(hintsDestinationHost);
        }
    }

    public void move(String newToken) throws IOException
    {
        try
        {
            getTokenFactory().validate(newToken);
        }
        catch (ConfigurationException e)
        {
            throw new IOException(e.getMessage());
        }
        move(getTokenFactory().fromString(newToken));
    }

    /**
     * move the node to new token or find a new token to boot to according to load
     *
     * @param newToken new token to boot to, or if null, find balanced token to boot to
     *
     * @throws IOException on any I/O operation error
     */
    private void move(Token newToken) throws IOException
    {
        if (newToken == null)
            throw new IOException("Can't move to the undefined (null) token.");

        if (tokenMetadata.sortedTokens().contains(newToken))
            throw new IOException("target token " + newToken + " is already owned by another node.");

        // address of the current node
        InetAddressAndPort localAddress = FBUtilities.getBroadcastAddressAndPort();

        // This doesn't make any sense in a vnodes environment.
        if (getTokenMetadata().getTokens(localAddress).size() > 1)
        {
            logger.error("Invalid request to move(Token); This node has more than one token and cannot be moved thusly.");
            throw new UnsupportedOperationException("This node has more than one token and cannot be moved thusly.");
        }

        List<String> keyspacesToProcess = ImmutableList.copyOf(Schema.instance.getNonLocalStrategyKeyspaces().names());

        PendingRangeCalculatorService.instance.blockUntilFinished();
        // checking if data is moving to this node
        for (String keyspaceName : keyspacesToProcess)
        {
            // TODO: do we care about fixing transient/full self-movements here?
            if (tokenMetadata.getPendingRanges(keyspaceName, localAddress).size() > 0)
                throw new UnsupportedOperationException("data is currently moving to this node; unable to leave the ring");
        }

        Gossiper.instance.addLocalApplicationState(ApplicationState.STATUS_WITH_PORT, valueFactory.moving(newToken));
        Gossiper.instance.addLocalApplicationState(ApplicationState.STATUS, valueFactory.moving(newToken));
        setMode(Mode.MOVING, String.format("Moving %s from %s to %s.", localAddress, getLocalTokens().iterator().next(), newToken), true);

        setMode(Mode.MOVING, String.format("Sleeping %s ms before start streaming/fetching ranges", RING_DELAY_MILLIS), true);
        Uninterruptibles.sleepUninterruptibly(RING_DELAY_MILLIS, MILLISECONDS);

        RangeRelocator relocator = new RangeRelocator(Collections.singleton(newToken), keyspacesToProcess, tokenMetadata);
        relocator.calculateToFromStreams();

        repairPaxosForTopologyChange("move");
        if (relocator.streamsNeeded())
        {
            setMode(Mode.MOVING, "fetching new ranges and streaming old ranges", true);
            try
            {
                relocator.stream().get();
            }
            catch (InterruptedException e)
            {
                throw new UncheckedInterruptedException(e);
            }
            catch (ExecutionException e)
            {
                throw new RuntimeException("Interrupted while waiting for stream/fetch ranges to finish: " + e.getMessage());
            }
        }
        else
        {
            setMode(Mode.MOVING, "No ranges to fetch/stream", true);
        }

        setTokens(Collections.singleton(newToken)); // setting new token as we have everything settled

        if (logger.isDebugEnabled())
            logger.debug("Successfully moved to new token {}", getLocalTokens().iterator().next());
    }

    public String getRemovalStatus()
    {
        return getRemovalStatus(false);
    }

    public String getRemovalStatusWithPort()
    {
        return getRemovalStatus(true);
    }

    /**
     * Get the status of a token removal.
     */
    private String getRemovalStatus(boolean withPort)
    {
        if (removingNode == null)
        {
            return "No token removals in process.";
        }

        Collection toFormat = replicatingNodes;
        if (!withPort)
        {
            toFormat = new ArrayList(replicatingNodes.size());
            for (InetAddressAndPort node : replicatingNodes)
            {
                toFormat.add(node.toString(false));
            }
        }

        return String.format("Removing token (%s). Waiting for replication confirmation from [%s].",
                             tokenMetadata.getToken(removingNode),
                             StringUtils.join(toFormat, ","));
    }

    /**
     * Force a remove operation to complete. This may be necessary if a remove operation
     * blocks forever due to node/stream failure. removeNode() must be called
     * first, this is a last resort measure.  No further attempt will be made to restore replicas.
     */
    public void forceRemoveCompletion()
    {
        if (!replicatingNodes.isEmpty()  || tokenMetadata.getSizeOfLeavingEndpoints() > 0)
        {
            logger.warn("Removal not confirmed for for {}", StringUtils.join(this.replicatingNodes, ","));
            for (InetAddressAndPort endpoint : tokenMetadata.getLeavingEndpoints())
            {
                UUID hostId = tokenMetadata.getHostId(endpoint);
                Gossiper.instance.advertiseTokenRemoved(endpoint, hostId);
                excise(tokenMetadata.getTokens(endpoint), endpoint);
            }
            replicatingNodes.clear();
            removingNode = null;
        }
        else
        {
            logger.warn("No nodes to force removal on, call 'removenode' first");
        }
    }

    /**
     * Remove a node that has died, attempting to restore the replica count.
     * If the node is alive, decommission should be attempted.  If decommission
     * fails, then removeNode should be called.  If we fail while trying to
     * restore the replica count, finally forceRemoveCompleteion should be
     * called to forcibly remove the node without regard to replica count.
     *
     * @param hostIdString Host ID for the node
     */
    public void removeNode(String hostIdString)
    {
        InetAddressAndPort myAddress = FBUtilities.getBroadcastAddressAndPort();
        UUID localHostId = tokenMetadata.getHostId(myAddress);
        UUID hostId = UUID.fromString(hostIdString);
        InetAddressAndPort endpoint = tokenMetadata.getEndpointForHostId(hostId);

        if (endpoint == null)
            throw new UnsupportedOperationException("Host ID not found.");

        if (!tokenMetadata.isMember(endpoint))
            throw new UnsupportedOperationException("Node to be removed is not a member of the token ring");

        if (endpoint.equals(myAddress))
             throw new UnsupportedOperationException("Cannot remove self");

        if (Gossiper.instance.getLiveMembers().contains(endpoint))
            throw new UnsupportedOperationException("Node " + endpoint + " is alive and owns this ID. Use decommission command to remove it from the ring");

        // A leaving endpoint that is dead is already being removed.
        if (tokenMetadata.isLeaving(endpoint))
            logger.warn("Node {} is already being removed, continuing removal anyway", endpoint);

        if (!replicatingNodes.isEmpty())
            throw new UnsupportedOperationException("This node is already processing a removal. Wait for it to complete, or use 'removenode force' if this has failed.");

        Collection<Token> tokens = tokenMetadata.getTokens(endpoint);

        // Find the endpoints that are going to become responsible for data
        for (String keyspaceName : Schema.instance.getNonLocalStrategyKeyspaces().names())
        {
            // if the replication factor is 1 the data is lost so we shouldn't wait for confirmation
            if (Keyspace.open(keyspaceName).getReplicationStrategy().getReplicationFactor().allReplicas == 1)
                continue;

            // get all ranges that change ownership (that is, a node needs
            // to take responsibility for new range)
            EndpointsByReplica changedRanges = getChangedReplicasForLeaving(keyspaceName, endpoint, tokenMetadata, Keyspace.open(keyspaceName).getReplicationStrategy());
            IFailureDetector failureDetector = FailureDetector.instance;
            for (InetAddressAndPort ep : transform(changedRanges.flattenValues(), Replica::endpoint))
            {
                if (failureDetector.isAlive(ep))
                    replicatingNodes.add(ep);
                else
                    logger.warn("Endpoint {} is down and will not receive data for re-replication of {}", ep, endpoint);
            }
        }
        removingNode = endpoint;

        tokenMetadata.addLeavingEndpoint(endpoint);
        PendingRangeCalculatorService.instance.update();

        // the gossiper will handle spoofing this node's state to REMOVING_TOKEN for us
        // we add our own token so other nodes to let us know when they're done
        Gossiper.instance.advertiseRemoving(endpoint, hostId, localHostId);

        // kick off streaming commands
        restoreReplicaCount(endpoint, myAddress);

        // wait for ReplicationDoneVerbHandler to signal we're done
        while (!replicatingNodes.isEmpty())
        {
            Uninterruptibles.sleepUninterruptibly(100, MILLISECONDS);
        }

        excise(tokens, endpoint);

        // gossiper will indicate the token has left
        Gossiper.instance.advertiseTokenRemoved(endpoint, hostId);

        replicatingNodes.clear();
        removingNode = null;
    }

    public void confirmReplication(InetAddressAndPort node)
    {
        // replicatingNodes can be empty in the case where this node used to be a removal coordinator,
        // but restarted before all 'replication finished' messages arrived. In that case, we'll
        // still go ahead and acknowledge it.
        if (!replicatingNodes.isEmpty())
        {
            replicatingNodes.remove(node);
        }
        else
        {
            logger.info("Received unexpected REPLICATION_FINISHED message from {}. Was this node recently a removal coordinator?", node);
        }
    }

    public String getOperationMode()
    {
        return operationMode.toString();
    }

    public boolean isStarting()
    {
        return operationMode == Mode.STARTING;
    }

    public boolean isMoving()
    {
        return operationMode == Mode.MOVING;
    }

    public boolean isJoining()
    {
        return operationMode == Mode.JOINING;
    }

    public boolean isDrained()
    {
        return operationMode == Mode.DRAINED;
    }

    public boolean isDraining()
    {
        return operationMode == Mode.DRAINING;
    }

    public boolean isNormal()
    {
        return operationMode == Mode.NORMAL;
    }

    public boolean isDecommissioned()
    {
        return operationMode == DECOMMISSIONED;
    }

    public boolean isDecommissionFailed()
    {
        return operationMode == DECOMMISSION_FAILED;
    }

    public boolean isDecommissioning()
    {
        return isDecommissioning.get();
    }

    public String getDrainProgress()
    {
        return String.format("Drained %s/%s ColumnFamilies", remainingCFs, totalCFs);
    }

    /**
     * Shuts node off to writes, empties memtables and the commit log.
     */
    public synchronized void drain() throws IOException, InterruptedException, ExecutionException
    {
        drain(false);
    }

    protected synchronized void drain(boolean isFinalShutdown) throws IOException, InterruptedException, ExecutionException
    {
        if (Stage.areMutationExecutorsTerminated())
        {
            if (!isFinalShutdown)
                logger.warn("Cannot drain node (did it already happen?)");
            return;
        }

        assert !isShutdown;
        isShutdown = true;

        Throwable preShutdownHookThrowable = Throwables.perform(null, preShutdownHooks.stream().map(h -> h::run));
        if (preShutdownHookThrowable != null)
            logger.error("Attempting to continue draining after pre-shutdown hooks returned exception", preShutdownHookThrowable);

        try
        {
            setMode(Mode.DRAINING, "starting drain process", !isFinalShutdown);

            try
            {
                /* not clear this is reasonable time, but propagated from prior embedded behaviour */
                BatchlogManager.instance.shutdownAndWait(1L, MINUTES);
            }
            catch (TimeoutException t)
            {
                logger.error("Batchlog manager timed out shutting down", t);
            }

            snapshotManager.stop();
            HintsService.instance.pauseDispatch();

            if (daemon != null)
                shutdownClientServers();
            ScheduledExecutors.optionalTasks.shutdown();
            Gossiper.instance.stop();
            ActiveRepairService.instance.stop();

            if (!isFinalShutdown)
                setMode(Mode.DRAINING, "shutting down MessageService", false);

            // In-progress writes originating here could generate hints to be written,
            // which is currently scheduled on the mutation stage. So shut down MessagingService
            // before mutation stage, so we can get all the hints saved before shutting down.
            try
            {
                MessagingService.instance().shutdown();
            }
            catch (Throwable t)
            {
                // prevent messaging service timing out shutdown from aborting
                // drain process; otherwise drain and/or shutdown might throw
                logger.error("Messaging service timed out shutting down", t);
            }

            if (!isFinalShutdown)
                setMode(Mode.DRAINING, "clearing mutation stage", false);
            Stage.shutdownAndAwaitMutatingExecutors(false,
                                                    DRAIN_EXECUTOR_TIMEOUT_MS.getInt(), TimeUnit.MILLISECONDS);

            StorageProxy.instance.verifyNoHintsInProgress();

            if (!isFinalShutdown)
                setMode(Mode.DRAINING, "flushing column families", false);

            // we don't want to start any new compactions while we are draining
            disableAutoCompaction();

            // count CFs first, since forceFlush could block for the flushWriter to get a queue slot empty
            totalCFs = 0;
            for (Keyspace keyspace : Keyspace.nonSystem())
                totalCFs += keyspace.getColumnFamilyStores().size();
            remainingCFs = totalCFs;
            // flush
            List<Future<?>> flushes = new ArrayList<>();
            for (Keyspace keyspace : Keyspace.nonSystem())
            {
                for (ColumnFamilyStore cfs : keyspace.getColumnFamilyStores())
                    flushes.add(cfs.forceFlush(ColumnFamilyStore.FlushReason.DRAIN));
            }
            // wait for the flushes.
            // TODO this is a godawful way to track progress, since they flush in parallel.  a long one could
            // thus make several short ones "instant" if we wait for them later.
            for (Future f : flushes)
            {
                try
                {
                    FBUtilities.waitOnFuture(f);
                }
                catch (Throwable t)
                {
                    JVMStabilityInspector.inspectThrowable(t);
                    // don't let this stop us from shutting down the commitlog and other thread pools
                    logger.warn("Caught exception while waiting for memtable flushes during shutdown hook", t);
                }

                remainingCFs--;
            }

            // Interrupt ongoing compactions and shutdown CM to prevent further compactions.
            CompactionManager.instance.forceShutdown();
            // Flush the system tables after all other tables are flushed, just in case flushing modifies any system state
            // like CASSANDRA-5151. Don't bother with progress tracking since system data is tiny.
            // Flush system tables after stopping compactions since they modify
            // system tables (for example compactions can obsolete sstables and the tidiers in SSTableReader update
            // system tables, see SSTableReader.GlobalTidy)
            flushes.clear();
            for (Keyspace keyspace : Keyspace.system())
            {
                for (ColumnFamilyStore cfs : keyspace.getColumnFamilyStores())
                    flushes.add(cfs.forceFlush(ColumnFamilyStore.FlushReason.DRAIN));
            }
            FBUtilities.waitOnFutures(flushes);

            SnapshotManager.shutdownAndWait(1L, MINUTES);
            HintsService.instance.shutdownBlocking();

            // Interrupt ongoing compactions and shutdown CM to prevent further compactions.
            CompactionManager.instance.forceShutdown();

            // whilst we've flushed all the CFs, which will have recycled all completed segments, we want to ensure
            // there are no segments to replay, so we force the recycling of any remaining (should be at most one)
            CommitLog.instance.forceRecycleAllSegments();

            CommitLog.instance.shutdownBlocking();

            // wait for miscellaneous tasks like sstable and commitlog segment deletion
            ColumnFamilyStore.shutdownPostFlushExecutor();

            try
            {
                // we are not shutting down ScheduledExecutors#scheduledFastTasks to be still able to progress time
                // fast-tasks executor is shut down in StorageService's shutdown hook added to Runtime
                ExecutorUtils.shutdownNowAndWait(1, MINUTES,
                                                 ScheduledExecutors.nonPeriodicTasks,
                                                 ScheduledExecutors.scheduledTasks,
                                                 ScheduledExecutors.optionalTasks);
            }
            finally
            {
                setMode(Mode.DRAINED, !isFinalShutdown);
            }
        }
        catch (Throwable t)
        {
            logger.error("Caught an exception while draining ", t);
        }
        finally
        {
            Throwable postShutdownHookThrowable = Throwables.perform(null, postShutdownHooks.stream().map(h -> h::run));
            if (postShutdownHookThrowable != null)
                logger.error("Post-shutdown hooks returned exception", postShutdownHookThrowable);
        }
    }

    @VisibleForTesting
    public void disableAutoCompaction()
    {
        for (Keyspace keyspace : Keyspace.all())
            for (ColumnFamilyStore cfs : keyspace.getColumnFamilyStores())
                cfs.disableAutoCompaction();
    }

    /**
     * Add a runnable which will be called before shut down or drain. This is useful for other
     * applications running in the same JVM which may want to shut down first rather than time
     * out attempting to use Cassandra calls which will no longer work.
     * @param hook: the code to run
     * @return true on success, false if Cassandra is already shutting down, in which case the runnable
     * has NOT been added.
     */
    public synchronized boolean addPreShutdownHook(Runnable hook)
    {
        if (!isDraining() && !isDrained())
            return preShutdownHooks.add(hook);

        return false;
    }

    /**
     * Remove a preshutdown hook
     */
    public synchronized boolean removePreShutdownHook(Runnable hook)
    {
        return preShutdownHooks.remove(hook);
    }

    /**
     * Add a runnable which will be called after shutdown or drain. This is useful for other applications
     * running in the same JVM that Cassandra needs to work and should shut down later.
     * @param hook: the code to run
     * @return true on success, false if Cassandra is already shutting down, in which case the runnable has NOT been
     * added.
     */
    public synchronized boolean addPostShutdownHook(Runnable hook)
    {
        if (!isDraining() && !isDrained())
            return postShutdownHooks.add(hook);

        return false;
    }

    /**
     * Remove a postshutdownhook
     */
    public synchronized boolean removePostShutdownHook(Runnable hook)
    {
        return postShutdownHooks.remove(hook);
    }

    /**
     * Some services are shutdown during draining and we should not attempt to start them again.
     *
     * @param service - the name of the service we are trying to start.
     * @throws IllegalStateException - an exception that nodetool is able to convert into a message to display to the user
     */
    synchronized void checkServiceAllowedToStart(String service)
    {
        if (isDraining()) // when draining isShutdown is also true, so we check first to return a more accurate message
            throw new IllegalStateException(String.format("Unable to start %s because the node is draining.", service));

        if (isShutdown()) // do not rely on operationMode in case it gets changed to decomissioned or other
            throw new IllegalStateException(String.format("Unable to start %s because the node was drained.", service));

        if (!isNormal() && joinRing) // if the node is not joining the ring, it is gossipping-only member which is in STARTING state forever
            throw new IllegalStateException(String.format("Unable to start %s because the node is not in the normal state.", service));
    }

    // Never ever do this at home. Used by tests.
    @VisibleForTesting
    public IPartitioner setPartitionerUnsafe(IPartitioner newPartitioner)
    {
        IPartitioner oldPartitioner = DatabaseDescriptor.setPartitionerUnsafe(newPartitioner);
        tokenMetadata = tokenMetadata.cloneWithNewPartitioner(newPartitioner);
        valueFactory = new VersionedValue.VersionedValueFactory(newPartitioner);
        return oldPartitioner;
    }

    TokenMetadata setTokenMetadataUnsafe(TokenMetadata tmd)
    {
        TokenMetadata old = tokenMetadata;
        tokenMetadata = tmd;
        return old;
    }

    public void truncate(String keyspace, String table) throws TimeoutException, IOException
    {
        verifyKeyspaceIsValid(keyspace);

        try
        {
            StorageProxy.truncateBlocking(keyspace, table);
        }
        catch (UnavailableException e)
        {
            throw new IOException(e.getMessage());
        }
    }

    public Map<InetAddress, Float> getOwnership()
    {
        List<Token> sortedTokens = tokenMetadata.sortedTokens();
        // describeOwnership returns tokens in an unspecified order, let's re-order them
        Map<Token, Float> tokenMap = new TreeMap<Token, Float>(tokenMetadata.partitioner.describeOwnership(sortedTokens));
        Map<InetAddress, Float> nodeMap = new LinkedHashMap<>();
        for (Map.Entry<Token, Float> entry : tokenMap.entrySet())
        {
            InetAddressAndPort endpoint = tokenMetadata.getEndpoint(entry.getKey());
            Float tokenOwnership = entry.getValue();
            if (nodeMap.containsKey(endpoint.getAddress()))
                nodeMap.put(endpoint.getAddress(), nodeMap.get(endpoint.getAddress()) + tokenOwnership);
            else
                nodeMap.put(endpoint.getAddress(), tokenOwnership);
        }
        return nodeMap;
    }

    public Map<String, Float> getOwnershipWithPort()
    {
        List<Token> sortedTokens = tokenMetadata.sortedTokens();
        // describeOwnership returns tokens in an unspecified order, let's re-order them
        Map<Token, Float> tokenMap = new TreeMap<Token, Float>(tokenMetadata.partitioner.describeOwnership(sortedTokens));
        Map<String, Float> nodeMap = new LinkedHashMap<>();
        for (Map.Entry<Token, Float> entry : tokenMap.entrySet())
        {
            InetAddressAndPort endpoint = tokenMetadata.getEndpoint(entry.getKey());
            Float tokenOwnership = entry.getValue();
            if (nodeMap.containsKey(endpoint.toString()))
                nodeMap.put(endpoint.toString(), nodeMap.get(endpoint.toString()) + tokenOwnership);
            else
                nodeMap.put(endpoint.toString(), tokenOwnership);
        }
        return nodeMap;
    }

    /**
     * Calculates ownership. If there are multiple DC's and the replication strategy is DC aware then ownership will be
     * calculated per dc, i.e. each DC will have total ring ownership divided amongst its nodes. Without replication
     * total ownership will be a multiple of the number of DC's and this value will then go up within each DC depending
     * on the number of replicas within itself. For DC unaware replication strategies, ownership without replication
     * will be 100%.
     *
     * @throws IllegalStateException when node is not configured properly.
     */
    private LinkedHashMap<InetAddressAndPort, Float> getEffectiveOwnership(String keyspace)
    {
        AbstractReplicationStrategy strategy;
        if (keyspace != null)
        {
            Keyspace keyspaceInstance = Schema.instance.getKeyspaceInstance(keyspace);
            if (keyspaceInstance == null)
                throw new IllegalArgumentException("The keyspace " + keyspace + ", does not exist");

            if (keyspaceInstance.getReplicationStrategy() instanceof LocalStrategy)
                throw new IllegalStateException("Ownership values for keyspaces with LocalStrategy are meaningless");
            strategy = keyspaceInstance.getReplicationStrategy();
        }
        else
        {
            Collection<String> userKeyspaces = Schema.instance.getUserKeyspaces().names();

            if (userKeyspaces.size() > 0)
            {
                keyspace = userKeyspaces.iterator().next();
                AbstractReplicationStrategy replicationStrategy = Schema.instance.getKeyspaceInstance(keyspace).getReplicationStrategy();
                for (String keyspaceName : userKeyspaces)
                {
                    if (!Schema.instance.getKeyspaceInstance(keyspaceName).getReplicationStrategy().hasSameSettings(replicationStrategy))
                        throw new IllegalStateException("Non-system keyspaces don't have the same replication settings, effective ownership information is meaningless");
                }
            }
            else
            {
                keyspace = "system_traces";
            }

            Keyspace keyspaceInstance = Schema.instance.getKeyspaceInstance(keyspace);
            if (keyspaceInstance == null)
                throw new IllegalStateException("The node does not have " + keyspace + " yet, probably still bootstrapping. Effective ownership information is meaningless.");
            strategy = keyspaceInstance.getReplicationStrategy();
        }

        TokenMetadata metadata = tokenMetadata.cloneOnlyTokenMap();

        Collection<Collection<InetAddressAndPort>> endpointsGroupedByDc = new ArrayList<>();
        // mapping of dc's to nodes, use sorted map so that we get dcs sorted
        SortedMap<String, Collection<InetAddressAndPort>> sortedDcsToEndpoints = new TreeMap<>(metadata.getTopology().getDatacenterEndpoints().asMap());
        for (Collection<InetAddressAndPort> endpoints : sortedDcsToEndpoints.values())
            endpointsGroupedByDc.add(endpoints);

        Map<Token, Float> tokenOwnership = tokenMetadata.partitioner.describeOwnership(tokenMetadata.sortedTokens());
        LinkedHashMap<InetAddressAndPort, Float> finalOwnership = Maps.newLinkedHashMap();

        RangesByEndpoint endpointToRanges = strategy.getAddressReplicas();
        // calculate ownership per dc
        for (Collection<InetAddressAndPort> endpoints : endpointsGroupedByDc)
        {
            // calculate the ownership with replication and add the endpoint to the final ownership map
            for (InetAddressAndPort endpoint : endpoints)
            {
                float ownership = 0.0f;
                for (Replica replica : endpointToRanges.get(endpoint))
                {
                    if (tokenOwnership.containsKey(replica.range().right))
                        ownership += tokenOwnership.get(replica.range().right);
                }
                finalOwnership.put(endpoint, ownership);
            }
        }
        return finalOwnership;
    }

    public LinkedHashMap<InetAddress, Float> effectiveOwnership(String keyspace) throws IllegalStateException
    {
        LinkedHashMap<InetAddressAndPort, Float> result = getEffectiveOwnership(keyspace);
        LinkedHashMap<InetAddress, Float> asInets = new LinkedHashMap<>();
        result.entrySet().stream().forEachOrdered(entry -> asInets.put(entry.getKey().getAddress(), entry.getValue()));
        return asInets;
    }

    public LinkedHashMap<String, Float> effectiveOwnershipWithPort(String keyspace) throws IllegalStateException
    {
        LinkedHashMap<InetAddressAndPort, Float> result = getEffectiveOwnership(keyspace);
        LinkedHashMap<String, Float> asStrings = new LinkedHashMap<>();
        result.entrySet().stream().forEachOrdered(entry -> asStrings.put(entry.getKey().getHostAddressAndPort(), entry.getValue()));
        return asStrings;
    }

    public List<String> getKeyspaces()
    {
        return Lists.newArrayList(Schema.instance.distributedAndLocalKeyspaces().names());
    }

    public List<String> getNonSystemKeyspaces()
    {
        return Lists.newArrayList(Schema.instance.distributedKeyspaces().names());
    }

    public List<String> getNonLocalStrategyKeyspaces()
    {
        return Lists.newArrayList(Schema.instance.getNonLocalStrategyKeyspaces().names());
    }

    public Map<String, String> getViewBuildStatuses(String keyspace, String view, boolean withPort)
    {
        Map<UUID, String> coreViewStatus = SystemDistributedKeyspace.viewStatus(keyspace, view);
        Map<InetAddressAndPort, UUID> hostIdToEndpoint = tokenMetadata.getEndpointToHostIdMapForReading();
        Map<String, String> result = new HashMap<>();

        for (Map.Entry<InetAddressAndPort, UUID> entry : hostIdToEndpoint.entrySet())
        {
            UUID hostId = entry.getValue();
            InetAddressAndPort endpoint = entry.getKey();
            result.put(endpoint.toString(withPort),
                       coreViewStatus.getOrDefault(hostId, "UNKNOWN"));
        }

        return Collections.unmodifiableMap(result);
    }

    public Map<String, String> getViewBuildStatuses(String keyspace, String view)
    {
        return getViewBuildStatuses(keyspace, view, false);
    }

    public Map<String, String> getViewBuildStatusesWithPort(String keyspace, String view)
    {
        return getViewBuildStatuses(keyspace, view, true);
    }

    public void setDynamicUpdateInterval(int dynamicUpdateInterval)
    {
        if (DatabaseDescriptor.getEndpointSnitch() instanceof DynamicEndpointSnitch)
        {

            try
            {
                updateSnitch(null, true, dynamicUpdateInterval, null, null);
            }
            catch (ClassNotFoundException e)
            {
                throw new RuntimeException(e);
            }
        }
    }

    public int getDynamicUpdateInterval()
    {
        return DatabaseDescriptor.getDynamicUpdateInterval();
    }

    public void updateSnitch(String epSnitchClassName, Boolean dynamic, Integer dynamicUpdateInterval, Integer dynamicResetInterval, Double dynamicBadnessThreshold) throws ClassNotFoundException
    {
        // apply dynamic snitch configuration
        if (dynamicUpdateInterval != null)
            DatabaseDescriptor.setDynamicUpdateInterval(dynamicUpdateInterval);
        if (dynamicResetInterval != null)
            DatabaseDescriptor.setDynamicResetInterval(dynamicResetInterval);
        if (dynamicBadnessThreshold != null)
            DatabaseDescriptor.setDynamicBadnessThreshold(dynamicBadnessThreshold);

        IEndpointSnitch oldSnitch = DatabaseDescriptor.getEndpointSnitch();

        // new snitch registers mbean during construction
        if(epSnitchClassName != null)
        {

            // need to unregister the mbean _before_ the new dynamic snitch is instantiated (and implicitly initialized
            // and its mbean registered)
            if (oldSnitch instanceof DynamicEndpointSnitch)
                ((DynamicEndpointSnitch)oldSnitch).close();

            IEndpointSnitch newSnitch;
            try
            {
                newSnitch = DatabaseDescriptor.createEndpointSnitch(dynamic != null && dynamic, epSnitchClassName);
            }
            catch (ConfigurationException e)
            {
                throw new ClassNotFoundException(e.getMessage());
            }

            if (newSnitch instanceof DynamicEndpointSnitch)
            {
                logger.info("Created new dynamic snitch {} with update-interval={}, reset-interval={}, badness-threshold={}",
                            ((DynamicEndpointSnitch)newSnitch).subsnitch.getClass().getName(), DatabaseDescriptor.getDynamicUpdateInterval(),
                            DatabaseDescriptor.getDynamicResetInterval(), DatabaseDescriptor.getDynamicBadnessThreshold());
            }
            else
            {
                logger.info("Created new non-dynamic snitch {}", newSnitch.getClass().getName());
            }

            // point snitch references to the new instance
            DatabaseDescriptor.setEndpointSnitch(newSnitch);
            for (String ks : Schema.instance.getKeyspaces())
            {
                Keyspace.open(ks).getReplicationStrategy().snitch = newSnitch;
            }
        }
        else
        {
            if (oldSnitch instanceof DynamicEndpointSnitch)
            {
                logger.info("Applying config change to dynamic snitch {} with update-interval={}, reset-interval={}, badness-threshold={}",
                            ((DynamicEndpointSnitch)oldSnitch).subsnitch.getClass().getName(), DatabaseDescriptor.getDynamicUpdateInterval(),
                            DatabaseDescriptor.getDynamicResetInterval(), DatabaseDescriptor.getDynamicBadnessThreshold());

                DynamicEndpointSnitch snitch = (DynamicEndpointSnitch)oldSnitch;
                snitch.applyConfigChanges();
            }
        }

        updateTopology();
    }

    /**
     * Send data to the endpoints that will be responsible for it in the future
     *
     * @param rangesToStreamByKeyspace keyspaces and data ranges with endpoints included for each
     * @return async Future for whether stream was success
     */
    private Future<StreamState> streamRanges(Map<String, EndpointsByReplica> rangesToStreamByKeyspace)
    {
        // First, we build a list of ranges to stream to each host, per table
        Map<String, RangesByEndpoint> sessionsToStreamByKeyspace = new HashMap<>();

        for (Map.Entry<String, EndpointsByReplica> entry : rangesToStreamByKeyspace.entrySet())
        {
            String keyspace = entry.getKey();
            EndpointsByReplica rangesWithEndpoints = entry.getValue();

            if (rangesWithEndpoints.isEmpty())
                continue;

            //Description is always Unbootstrap? Is that right?
            Map<InetAddressAndPort, Set<Range<Token>>> transferredRangePerKeyspace = SystemKeyspace.getTransferredRanges("Unbootstrap",
                                                                                                                         keyspace,
                                                                                                                         StorageService.instance.getTokenMetadata().partitioner);
            RangesByEndpoint.Builder replicasPerEndpoint = new RangesByEndpoint.Builder();
            for (Map.Entry<Replica, Replica> endPointEntry : rangesWithEndpoints.flattenEntries())
            {
                Replica local = endPointEntry.getKey();
                Replica remote = endPointEntry.getValue();
                Set<Range<Token>> transferredRanges = transferredRangePerKeyspace.get(remote.endpoint());
                if (transferredRanges != null && transferredRanges.contains(local.range()))
                {
                    logger.debug("Skipping transferred range {} of keyspace {}, endpoint {}", local, keyspace, remote);
                    continue;
                }

                replicasPerEndpoint.put(remote.endpoint(), remote.decorateSubrange(local.range()));
            }

            sessionsToStreamByKeyspace.put(keyspace, replicasPerEndpoint.build());
        }

        StreamPlan streamPlan = new StreamPlan(StreamOperation.DECOMMISSION);

        // Vinculate StreamStateStore to current StreamPlan to update transferred rangeas per StreamSession
        streamPlan.listeners(streamStateStore);

        for (Map.Entry<String, RangesByEndpoint> entry : sessionsToStreamByKeyspace.entrySet())
        {
            String keyspaceName = entry.getKey();
            RangesByEndpoint replicasPerEndpoint = entry.getValue();

            for (Map.Entry<InetAddressAndPort, RangesAtEndpoint> rangesEntry : replicasPerEndpoint.asMap().entrySet())
            {
                RangesAtEndpoint replicas = rangesEntry.getValue();
                InetAddressAndPort newEndpoint = rangesEntry.getKey();

                // TODO each call to transferRanges re-flushes, this is potentially a lot of waste
                streamPlan.transferRanges(newEndpoint, keyspaceName, replicas);
            }
        }
        return streamPlan.execute();
    }

    public void bulkLoad(String directory)
    {
        try
        {
            bulkLoadInternal(directory).get();
        }
        catch (Exception e)
        {
            throw new RuntimeException(e);
        }
    }

    public String bulkLoadAsync(String directory)
    {
        return bulkLoadInternal(directory).planId.toString();
    }

    private StreamResultFuture bulkLoadInternal(String directory)
    {
        File dir = new File(directory);

        if (!dir.exists() || !dir.isDirectory())
            throw new IllegalArgumentException("Invalid directory " + directory);

        SSTableLoader.Client client = new SSTableLoader.Client()
        {
            private String keyspace;

            public void init(String keyspace)
            {
                this.keyspace = keyspace;
                try
                {
                    for (Map.Entry<Range<Token>, EndpointsForRange> entry : StorageService.instance.getRangeToAddressMap(keyspace).entrySet())
                    {
                        Range<Token> range = entry.getKey();
                        EndpointsForRange replicas = entry.getValue();
                        Replicas.temporaryAssertFull(replicas);
                        for (InetAddressAndPort endpoint : replicas.endpoints())
                            addRangeForEndpoint(range, endpoint);
                    }
                }
                catch (Exception e)
                {
                    throw new RuntimeException(e);
                }
            }

            public TableMetadataRef getTableMetadata(String tableName)
            {
                return Schema.instance.getTableMetadataRef(keyspace, tableName);
            }
        };

        return new SSTableLoader(dir, client, new OutputHandler.LogOutput()).stream();
    }

    public void rescheduleFailedDeletions()
    {
        LifecycleTransaction.rescheduleFailedDeletions();
    }

    /**
     * #{@inheritDoc}
     */
    @Deprecated
    public void loadNewSSTables(String ksName, String cfName)
    {
        if (!isInitialized())
            throw new RuntimeException("Not yet initialized, can't load new sstables");
        verifyKeyspaceIsValid(ksName);
        ColumnFamilyStore.loadNewSSTables(ksName, cfName);
    }

    /**
     * #{@inheritDoc}
     */
    public List<String> sampleKeyRange() // do not rename to getter - see CASSANDRA-4452 for details
    {
        List<DecoratedKey> keys = new ArrayList<>();
        for (Keyspace keyspace : Keyspace.nonLocalStrategy())
        {
            for (Range<Token> range : getPrimaryRangesForEndpoint(keyspace.getName(), FBUtilities.getBroadcastAddressAndPort()))
                keys.addAll(keySamples(keyspace.getColumnFamilyStores(), range));
        }

        List<String> sampledKeys = new ArrayList<>(keys.size());
        for (DecoratedKey key : keys)
            sampledKeys.add(key.getToken().toString());
        return sampledKeys;
    }

    @Override
    public Map<String, List<CompositeData>> samplePartitions(int duration, int capacity, int count, List<String> samplers) throws OpenDataException {
        return samplePartitions(null, duration, capacity, count, samplers);
    }

    /*
     * { "sampler_name": [ {table: "", count: i, error: i, value: ""}, ... ] }
     */
    @Override
    public Map<String, List<CompositeData>> samplePartitions(String keyspace, int durationMillis, int capacity, int count,
                                                             List<String> samplers) throws OpenDataException
    {
        ConcurrentHashMap<String, List<CompositeData>> result = new ConcurrentHashMap<>();
        Iterable<ColumnFamilyStore> tables = SamplingManager.getTables(keyspace, null);
        for (String sampler : samplers)
        {
            for (ColumnFamilyStore table : tables)
            {
                table.beginLocalSampling(sampler, capacity, durationMillis);
            }
        }
        Uninterruptibles.sleepUninterruptibly(durationMillis, MILLISECONDS);

        for (String sampler : samplers)
        {
            List<CompositeData> topk = new ArrayList<>();
            for (ColumnFamilyStore table : tables)
            {
                topk.addAll(table.finishLocalSampling(sampler, count));
            }
            Collections.sort(topk, new Ordering<CompositeData>()
            {
                public int compare(CompositeData left, CompositeData right)
                {
                    return Long.compare((long) right.get("count"), (long) left.get("count"));
                }
            });
            // sublist is not serializable for jmx
            topk = new ArrayList<>(topk.subList(0, Math.min(topk.size(), count)));
            result.put(sampler, topk);
        }
        return result;
    }

    @Override // Note from parent javadoc: ks and table are nullable
    public boolean startSamplingPartitions(String ks, String table, int duration, int interval, int capacity, int count, List<String> samplers)
    {
        Preconditions.checkArgument(duration > 0, "Sampling duration %s must be positive.", duration);

        Preconditions.checkArgument(interval <= 0 || interval >= duration,
                                    "Sampling interval %s should be greater then or equals to duration %s if defined.",
                                    interval, duration);

        Preconditions.checkArgument(capacity > 0 && capacity <= 1024,
                                    "Sampling capacity %s must be positive and the max value is 1024 (inclusive).",
                                    capacity);

        Preconditions.checkArgument(count > 0 && count < capacity,
                                    "Sampling count %s must be positive and smaller than capacity %s.",
                                    count, capacity);

        Preconditions.checkArgument(!samplers.isEmpty(), "Samplers cannot be empty.");

        Set<Sampler.SamplerType> available = EnumSet.allOf(Sampler.SamplerType.class);
        samplers.forEach((x) -> checkArgument(available.contains(Sampler.SamplerType.valueOf(x)),
                                              "'%s' sampler is not available from: %s",
                                              x, Arrays.toString(Sampler.SamplerType.values())));
        return samplingManager.register(ks, table, duration, interval, capacity, count, samplers);
    }

    @Override
    public boolean stopSamplingPartitions(String ks, String table)
    {
        return samplingManager.unregister(ks, table);
    }

    @Override
    public List<String> getSampleTasks()
    {
        return samplingManager.allJobs();
    }

    public void rebuildSecondaryIndex(String ksName, String cfName, String... idxNames)
    {
        String[] indices = asList(idxNames).stream()
                                           .map(p -> isIndexColumnFamily(p) ? getIndexName(p) : p)
                                           .collect(toList())
                                           .toArray(new String[idxNames.length]);

        ColumnFamilyStore.rebuildSecondaryIndex(ksName, cfName, indices);
    }

    public void resetLocalSchema() throws IOException
    {
        Schema.instance.resetLocalSchema();
    }

    public void reloadLocalSchema()
    {
        Schema.instance.reloadSchemaAndAnnounceVersion();
    }

    public void setTraceProbability(double probability)
    {
        this.traceProbability = probability;
    }

    public double getTraceProbability()
    {
        return traceProbability;
    }

    public boolean shouldTraceProbablistically()
    {
        return traceProbability != 0 && ThreadLocalRandom.current().nextDouble() < traceProbability;
    }

    public void disableAutoCompaction(String ks, String... tables) throws IOException
    {
        for (ColumnFamilyStore cfs : getValidColumnFamilies(true, true, ks, tables))
        {
            cfs.disableAutoCompaction();
        }
    }

    public synchronized void enableAutoCompaction(String ks, String... tables) throws IOException
    {
        checkServiceAllowedToStart("auto compaction");

        for (ColumnFamilyStore cfs : getValidColumnFamilies(true, true, ks, tables))
        {
            cfs.enableAutoCompaction();
        }
    }

    public Map<String, Boolean> getAutoCompactionStatus(String ks, String... tables) throws IOException
    {
        Map<String, Boolean> status = new HashMap<String, Boolean>();
        for (ColumnFamilyStore cfs : getValidColumnFamilies(true, true, ks, tables))
            status.put(cfs.getTableName(), cfs.isAutoCompactionDisabled());
        return status;
    }

    /** Returns the name of the cluster */
    public String getClusterName()
    {
        return DatabaseDescriptor.getClusterName();
    }

    /** Returns the cluster partitioner */
    public String getPartitionerName()
    {
        return DatabaseDescriptor.getPartitionerName();
    }

    /** Negative number for disabled */
    public void setSSTablePreemptiveOpenIntervalInMB(int intervalInMB)
    {
        DatabaseDescriptor.setSSTablePreemptiveOpenIntervalInMiB(intervalInMB);
    }

    /** This method can return negative number for disabled */
    public int getSSTablePreemptiveOpenIntervalInMB()
    {
        return DatabaseDescriptor.getSSTablePreemptiveOpenIntervalInMiB();
    }

    public boolean getMigrateKeycacheOnCompaction()
    {
        return DatabaseDescriptor.shouldMigrateKeycacheOnCompaction();
    }

    public void setMigrateKeycacheOnCompaction(boolean invalidateKeyCacheOnCompaction)
    {
        DatabaseDescriptor.setMigrateKeycacheOnCompaction(invalidateKeyCacheOnCompaction);
    }

    public int getTombstoneWarnThreshold()
    {
        return DatabaseDescriptor.getTombstoneWarnThreshold();
    }

    public void setTombstoneWarnThreshold(int threshold)
    {
        DatabaseDescriptor.setTombstoneWarnThreshold(threshold);
        logger.info("updated tombstone_warn_threshold to {}", threshold);
    }

    public int getTombstoneFailureThreshold()
    {
        return DatabaseDescriptor.getTombstoneFailureThreshold();
    }

    public void setTombstoneFailureThreshold(int threshold)
    {
        DatabaseDescriptor.setTombstoneFailureThreshold(threshold);
        logger.info("updated tombstone_failure_threshold to {}", threshold);
    }

    public int getCachedReplicaRowsWarnThreshold()
    {
        return DatabaseDescriptor.getCachedReplicaRowsWarnThreshold();
    }

    public void setCachedReplicaRowsWarnThreshold(int threshold)
    {
        DatabaseDescriptor.setCachedReplicaRowsWarnThreshold(threshold);
        logger.info("updated replica_filtering_protection.cached_rows_warn_threshold to {}", threshold);
    }

    public int getCachedReplicaRowsFailThreshold()
    {
        return DatabaseDescriptor.getCachedReplicaRowsFailThreshold();
    }

    public void setCachedReplicaRowsFailThreshold(int threshold)
    {
        DatabaseDescriptor.setCachedReplicaRowsFailThreshold(threshold);
        logger.info("updated replica_filtering_protection.cached_rows_fail_threshold to {}", threshold);
    }

    @Override
    public int getColumnIndexSizeInKiB()
    {
        return DatabaseDescriptor.getColumnIndexSizeInKiB();
    }

    @Override
    public void setColumnIndexSizeInKiB(int columnIndexSizeInKiB)
    {
        int oldValueInKiB = DatabaseDescriptor.getColumnIndexSizeInKiB();
        try
        {
            DatabaseDescriptor.setColumnIndexSizeInKiB(columnIndexSizeInKiB);
        }
        catch (ConfigurationException e)
        {
            throw new IllegalArgumentException(e.getMessage());
        }
        logger.info("Updated column_index_size to {} KiB (was {} KiB)", columnIndexSizeInKiB, oldValueInKiB);
    }

    @Deprecated
    @Override
    public void setColumnIndexSize(int columnIndexSizeInKB)
    {
        int oldValueInKiB = DatabaseDescriptor.getColumnIndexSizeInKiB();
        DatabaseDescriptor.setColumnIndexSizeInKiB(columnIndexSizeInKB);
        logger.info("Updated column_index_size to {} KiB (was {} KiB)", columnIndexSizeInKB, oldValueInKiB);
    }

    @Deprecated
    @Override
    public int getColumnIndexCacheSize()
    {
        return DatabaseDescriptor.getColumnIndexCacheSizeInKiB();
    }

    @Deprecated
    @Override
    public void setColumnIndexCacheSize(int cacheSizeInKB)
    {
        DatabaseDescriptor.setColumnIndexCacheSize(cacheSizeInKB);
        logger.info("Updated column_index_cache_size to {}", cacheSizeInKB);
    }

    /*
     * In CASSANDRA-17668, JMX setters that did not throw standard exceptions were deprecated in favor of ones that do.
     * For consistency purposes, the respective getter "getColumnIndexCacheSize" was also deprecated and replaced by
     * this method.
     */
    @Override
    public int getColumnIndexCacheSizeInKiB()
    {
        return DatabaseDescriptor.getColumnIndexCacheSizeInKiB();
    }

    @Override
    public void setColumnIndexCacheSizeInKiB(int cacheSizeInKiB)
    {
        try
        {
            DatabaseDescriptor.setColumnIndexCacheSize(cacheSizeInKiB);
        }
        catch (ConfigurationException e)
        {
            throw new IllegalArgumentException(e.getMessage());
        }
        logger.info("Updated column_index_cache_size to {}", cacheSizeInKiB);
    }

    public int getBatchSizeFailureThreshold()
    {
        return DatabaseDescriptor.getBatchSizeFailThresholdInKiB();
    }

    public void setBatchSizeFailureThreshold(int threshold)
    {
        DatabaseDescriptor.setBatchSizeFailThresholdInKiB(threshold);
        logger.info("updated batch_size_fail_threshold to {}", threshold);
    }

    @Deprecated
    @Override
    public int getBatchSizeWarnThreshold()
    {
        return DatabaseDescriptor.getBatchSizeWarnThresholdInKiB();
    }

    @Deprecated
    @Override
    public void setBatchSizeWarnThreshold(int threshold)
    {
        DatabaseDescriptor.setBatchSizeWarnThresholdInKiB(threshold);
        logger.info("Updated batch_size_warn_threshold to {}", threshold);
    }

    /*
     * In CASSANDRA-17668, JMX setters that did not throw standard exceptions were deprecated in favor of ones that do.
     * For consistency purposes, the respective getter "getBatchSizeWarnThreshold" was also deprecated and replaced by
     * this method.
     */
    @Override
    public int getBatchSizeWarnThresholdInKiB()
    {
        return DatabaseDescriptor.getBatchSizeWarnThresholdInKiB();
    }

    @Override
    public void setBatchSizeWarnThresholdInKiB(int thresholdInKiB)
    {
        try
        {
            DatabaseDescriptor.setBatchSizeWarnThresholdInKiB(thresholdInKiB);
        }
        catch (ConfigurationException e)
        {
            throw new IllegalArgumentException(e.getMessage());
        }

        logger.info("Updated batch_size_warn_threshold to {}", thresholdInKiB);
    }

    public int getInitialRangeTombstoneListAllocationSize()
    {
        return DatabaseDescriptor.getInitialRangeTombstoneListAllocationSize();
    }

    public void setInitialRangeTombstoneListAllocationSize(int size)
    {
        if (size < 0 || size > 1024)
        {
            throw new IllegalStateException("Not updating initial_range_tombstone_allocation_size as it must be in the range [0, 1024] inclusive");
        }
        int originalSize = DatabaseDescriptor.getInitialRangeTombstoneListAllocationSize();
        DatabaseDescriptor.setInitialRangeTombstoneListAllocationSize(size);
        logger.info("Updated initial_range_tombstone_allocation_size from {} to {}", originalSize, size);
    }

    public double getRangeTombstoneResizeListGrowthFactor()
    {
        return DatabaseDescriptor.getRangeTombstoneListGrowthFactor();
    }

    public void setRangeTombstoneListResizeGrowthFactor(double growthFactor) throws IllegalStateException
    {
        if (growthFactor < 1.2 || growthFactor > 5)
        {
            throw new IllegalStateException("Not updating range_tombstone_resize_factor as growth factor must be in the range [1.2, 5.0] inclusive");
        }
        else
        {
            double originalGrowthFactor = DatabaseDescriptor.getRangeTombstoneListGrowthFactor();
            DatabaseDescriptor.setRangeTombstoneListGrowthFactor(growthFactor);
            logger.info("Updated range_tombstone_resize_factor from {} to {}", originalGrowthFactor, growthFactor);
        }
    }

    public void setHintedHandoffThrottleInKB(int throttleInKB)
    {
        DatabaseDescriptor.setHintedHandoffThrottleInKiB(throttleInKB);
        logger.info("updated hinted_handoff_throttle to {} KiB", throttleInKB);
    }

    public boolean getTransferHintsOnDecommission()
    {
        return DatabaseDescriptor.getTransferHintsOnDecommission();
    }

    public void setTransferHintsOnDecommission(boolean enabled)
    {
        DatabaseDescriptor.setTransferHintsOnDecommission(enabled);
        logger.info("updated transfer_hints_on_decommission to {}", enabled);
    }

    @Override
    public void clearConnectionHistory()
    {
        daemon.clearConnectionHistory();
        logger.info("Cleared connection history");
    }
    public void disableAuditLog()
    {
        AuditLogManager.instance.disableAuditLog();
        logger.info("Auditlog is disabled");
    }

    @Deprecated
    public void enableAuditLog(String loggerName, String includedKeyspaces, String excludedKeyspaces, String includedCategories, String excludedCategories,
                               String includedUsers, String excludedUsers) throws ConfigurationException, IllegalStateException
    {
        enableAuditLog(loggerName, Collections.emptyMap(), includedKeyspaces, excludedKeyspaces, includedCategories, excludedCategories, includedUsers, excludedUsers,
                       Integer.MIN_VALUE, null, null, Long.MIN_VALUE, Integer.MIN_VALUE, null);
    }

    public void enableAuditLog(String loggerName, String includedKeyspaces, String excludedKeyspaces, String includedCategories, String excludedCategories,
                               String includedUsers, String excludedUsers, Integer maxArchiveRetries, Boolean block, String rollCycle,
                               Long maxLogSize, Integer maxQueueWeight, String archiveCommand) throws IllegalStateException
    {
        enableAuditLog(loggerName, Collections.emptyMap(), includedKeyspaces, excludedKeyspaces, includedCategories, excludedCategories, includedUsers, excludedUsers,
                       maxArchiveRetries, block, rollCycle, maxLogSize, maxQueueWeight, archiveCommand);
    }

    @Deprecated
    public void enableAuditLog(String loggerName, Map<String, String> parameters, String includedKeyspaces, String excludedKeyspaces, String includedCategories, String excludedCategories,
                               String includedUsers, String excludedUsers) throws ConfigurationException, IllegalStateException
    {
        enableAuditLog(loggerName, parameters, includedKeyspaces, excludedKeyspaces, includedCategories, excludedCategories, includedUsers, excludedUsers,
                       Integer.MIN_VALUE, null, null, Long.MIN_VALUE, Integer.MIN_VALUE, null);
    }

    public void enableAuditLog(String loggerName, Map<String, String> parameters, String includedKeyspaces, String excludedKeyspaces, String includedCategories, String excludedCategories,
                               String includedUsers, String excludedUsers, Integer maxArchiveRetries, Boolean block, String rollCycle,
                               Long maxLogSize, Integer maxQueueWeight, String archiveCommand) throws IllegalStateException
    {
        AuditLogOptions auditOptions = DatabaseDescriptor.getAuditLoggingOptions();
        if (archiveCommand != null && !auditOptions.allow_nodetool_archive_command)
            throw new ConfigurationException("Can't enable audit log archiving via nodetool unless audit_logging_options.allow_nodetool_archive_command is set to true");

        final AuditLogOptions options = new AuditLogOptions.Builder(auditOptions)
                                        .withEnabled(true)
                                        .withLogger(loggerName, parameters)
                                        .withIncludedKeyspaces(includedKeyspaces)
                                        .withExcludedKeyspaces(excludedKeyspaces)
                                        .withIncludedCategories(includedCategories)
                                        .withExcludedCategories(excludedCategories)
                                        .withIncludedUsers(includedUsers)
                                        .withExcludedUsers(excludedUsers)
                                        .withMaxArchiveRetries(maxArchiveRetries)
                                        .withBlock(block)
                                        .withRollCycle(rollCycle)
                                        .withMaxLogSize(maxLogSize)
                                        .withMaxQueueWeight(maxQueueWeight)
                                        .withArchiveCommand(archiveCommand)
                                        .build();

        AuditLogManager.instance.enable(options);
        logger.info("AuditLog is enabled with configuration: {}", options);
    }

    public boolean isAuditLogEnabled()
    {
        return AuditLogManager.instance.isEnabled();
    }

    public String getCorruptedTombstoneStrategy()
    {
        return DatabaseDescriptor.getCorruptedTombstoneStrategy().toString();
    }

    public void setCorruptedTombstoneStrategy(String strategy)
    {
        DatabaseDescriptor.setCorruptedTombstoneStrategy(Config.CorruptedTombstoneStrategy.valueOf(strategy));
        logger.info("Setting corrupted tombstone strategy to {}", strategy);
    }

    @Override
    public long getNativeTransportMaxConcurrentRequestsInBytes()
    {
        return ClientResourceLimits.getGlobalLimit();
    }

    @Override
    public void setNativeTransportMaxConcurrentRequestsInBytes(long newLimit)
    {
        ClientResourceLimits.setGlobalLimit(newLimit);
    }

    @Override
    public long getNativeTransportMaxConcurrentRequestsInBytesPerIp()
    {
        return ClientResourceLimits.getEndpointLimit();
    }

    @Override
    public void setNativeTransportMaxConcurrentRequestsInBytesPerIp(long newLimit)
    {
        ClientResourceLimits.setEndpointLimit(newLimit);
    }

    @Override
    public int getNativeTransportMaxRequestsPerSecond()
    {
        return ClientResourceLimits.getNativeTransportMaxRequestsPerSecond();
    }

    @Override
    public void setNativeTransportMaxRequestsPerSecond(int newPerSecond)
    {
        ClientResourceLimits.setNativeTransportMaxRequestsPerSecond(newPerSecond);
    }

    @Override
    public void setNativeTransportRateLimitingEnabled(boolean enabled)
    {
        DatabaseDescriptor.setNativeTransportRateLimitingEnabled(enabled);
    }

    @Override
    public boolean getNativeTransportRateLimitingEnabled()
    {
        return DatabaseDescriptor.getNativeTransportRateLimitingEnabled();
    }

    @VisibleForTesting
    public void shutdownServer()
    {
        if (drainOnShutdown != null)
        {
            Runtime.getRuntime().removeShutdownHook(drainOnShutdown);
        }
    }

    @Override
    public void enableFullQueryLogger(String path, String rollCycle, Boolean blocking, int maxQueueWeight, long maxLogSize, String archiveCommand, int maxArchiveRetries)
    {
        FullQueryLoggerOptions fqlOptions = DatabaseDescriptor.getFullQueryLogOptions();
        path = path != null ? path : fqlOptions.log_dir;
        rollCycle = rollCycle != null ? rollCycle : fqlOptions.roll_cycle;
        blocking = blocking != null ? blocking : fqlOptions.block;
        maxQueueWeight = maxQueueWeight != Integer.MIN_VALUE ? maxQueueWeight : fqlOptions.max_queue_weight;
        maxLogSize = maxLogSize != Long.MIN_VALUE ? maxLogSize : fqlOptions.max_log_size;
        if (archiveCommand != null && !fqlOptions.allow_nodetool_archive_command)
            throw new ConfigurationException("Can't enable full query log archiving via nodetool unless full_query_logging_options.allow_nodetool_archive_command is set to true");
        archiveCommand = archiveCommand != null ? archiveCommand : fqlOptions.archive_command;
        maxArchiveRetries = maxArchiveRetries != Integer.MIN_VALUE ? maxArchiveRetries : fqlOptions.max_archive_retries;

        Preconditions.checkNotNull(path, "cassandra.yaml did not set log_dir and not set as parameter");
        FullQueryLogger.instance.enableWithoutClean(File.getPath(path), rollCycle, blocking, maxQueueWeight, maxLogSize, archiveCommand, maxArchiveRetries);
    }

    @Override
    public void resetFullQueryLogger()
    {
        FullQueryLogger.instance.reset(DatabaseDescriptor.getFullQueryLogOptions().log_dir);
    }

    @Override
    public void stopFullQueryLogger()
    {
        FullQueryLogger.instance.stop();
    }

    @Override
    public boolean isFullQueryLogEnabled()
    {
        return FullQueryLogger.instance.isEnabled();
    }

    @Override
    public CompositeData getFullQueryLoggerOptions()
    {
        return FullQueryLoggerOptionsCompositeData.toCompositeData(FullQueryLogger.instance.getFullQueryLoggerOptions());
    }

    @Override
    public Map<String, Set<InetAddress>> getOutstandingSchemaVersions()
    {
        Map<UUID, Set<InetAddressAndPort>> outstanding = Schema.instance.getOutstandingSchemaVersions();
        return outstanding.entrySet().stream().collect(Collectors.toMap(e -> e.getKey().toString(),
                                                                        e -> e.getValue().stream().map(InetSocketAddress::getAddress).collect(Collectors.toSet())));
    }

    @Override
    public Map<String, Set<String>> getOutstandingSchemaVersionsWithPort()
    {
        Map<UUID, Set<InetAddressAndPort>> outstanding = Schema.instance.getOutstandingSchemaVersions();
        return outstanding.entrySet().stream().collect(Collectors.toMap(e -> e.getKey().toString(),
                                                                        e -> e.getValue().stream().map(Object::toString).collect(Collectors.toSet())));
    }

    public boolean autoOptimiseIncRepairStreams()
    {
        return DatabaseDescriptor.autoOptimiseIncRepairStreams();
    }

    public void setAutoOptimiseIncRepairStreams(boolean enabled)
    {
        DatabaseDescriptor.setAutoOptimiseIncRepairStreams(enabled);
    }

    public boolean autoOptimiseFullRepairStreams()
    {
        return DatabaseDescriptor.autoOptimiseFullRepairStreams();
    }

    public void setAutoOptimiseFullRepairStreams(boolean enabled)
    {
        DatabaseDescriptor.setAutoOptimiseFullRepairStreams(enabled);
    }

    public boolean autoOptimisePreviewRepairStreams()
    {
        return DatabaseDescriptor.autoOptimisePreviewRepairStreams();
    }

    public void setAutoOptimisePreviewRepairStreams(boolean enabled)
    {
        DatabaseDescriptor.setAutoOptimisePreviewRepairStreams(enabled);
    }

    @Deprecated
    public int getTableCountWarnThreshold()
    {
        return (int) Converters.TABLE_COUNT_THRESHOLD_TO_GUARDRAIL.unconvert(Guardrails.instance.getTablesWarnThreshold());
    }

    @Deprecated
    public void setTableCountWarnThreshold(int value)
    {
        if (value < 0)
            throw new IllegalStateException("Table count warn threshold should be positive, not "+value);
        logger.info("Changing table count warn threshold from {} to {}", getTableCountWarnThreshold(), value);
        Guardrails.instance.setTablesThreshold((int) Converters.TABLE_COUNT_THRESHOLD_TO_GUARDRAIL.convert(value), 
                                               Guardrails.instance.getTablesFailThreshold());
    }

    @Deprecated
    public int getKeyspaceCountWarnThreshold()
    {
        return (int) Converters.KEYSPACE_COUNT_THRESHOLD_TO_GUARDRAIL.unconvert(Guardrails.instance.getKeyspacesWarnThreshold());
    }

    @Deprecated
    public void setKeyspaceCountWarnThreshold(int value)
    {
        if (value < 0)
            throw new IllegalStateException("Keyspace count warn threshold should be positive, not "+value);
        logger.info("Changing keyspace count warn threshold from {} to {}", getKeyspaceCountWarnThreshold(), value);
        Guardrails.instance.setKeyspacesThreshold((int) Converters.KEYSPACE_COUNT_THRESHOLD_TO_GUARDRAIL.convert(value),
                                                  Guardrails.instance.getKeyspacesFailThreshold());
    }

    @Override
    public void setCompactionTombstoneWarningThreshold(int count)
    {
        if (count < 0)
            throw new IllegalStateException("compaction tombstone warning threshold needs to be >= 0, not "+count);
        logger.info("Setting compaction_tombstone_warning_threshold to {}", count);
        Guardrails.instance.setPartitionTombstonesThreshold(count, Guardrails.instance.getPartitionTombstonesFailThreshold());
    }

    @Override
    public int getCompactionTombstoneWarningThreshold()
    {
        return Math.toIntExact(Guardrails.instance.getPartitionTombstonesWarnThreshold());
    }

    public void addSnapshot(TableSnapshot snapshot) {
        snapshotManager.addSnapshot(snapshot);
    }

    @Override
    public boolean getReadThresholdsEnabled()
    {
        return DatabaseDescriptor.getReadThresholdsEnabled();
    }

    @Override
    public void setReadThresholdsEnabled(boolean value)
    {
        DatabaseDescriptor.setReadThresholdsEnabled(value);
    }

    @Override
    public String getCoordinatorLargeReadWarnThreshold()
    {
        return toString(DatabaseDescriptor.getCoordinatorReadSizeWarnThreshold());
    }

    @Override
    public void setCoordinatorLargeReadWarnThreshold(String threshold)
    {
        DatabaseDescriptor.setCoordinatorReadSizeWarnThreshold(parseDataStorageSpec(threshold));
    }

    @Override
    public String getCoordinatorLargeReadAbortThreshold()
    {
        return toString(DatabaseDescriptor.getCoordinatorReadSizeFailThreshold());
    }

    @Override
    public void setCoordinatorLargeReadAbortThreshold(String threshold)
    {
        DatabaseDescriptor.setCoordinatorReadSizeFailThreshold(parseDataStorageSpec(threshold));
    }

    @Override
    public String getLocalReadTooLargeWarnThreshold()
    {
        return toString(DatabaseDescriptor.getLocalReadSizeWarnThreshold());
    }

    @Override
    public void setLocalReadTooLargeWarnThreshold(String threshold)
    {
        DatabaseDescriptor.setLocalReadSizeWarnThreshold(parseDataStorageSpec(threshold));
    }

    @Override
    public String getLocalReadTooLargeAbortThreshold()
    {
        return toString(DatabaseDescriptor.getLocalReadSizeFailThreshold());
    }

    @Override
    public void setLocalReadTooLargeAbortThreshold(String threshold)
    {
        DatabaseDescriptor.setLocalReadSizeFailThreshold(parseDataStorageSpec(threshold));
    }

    @Override
    public String getRowIndexReadSizeWarnThreshold()
    {
        return toString(DatabaseDescriptor.getRowIndexReadSizeWarnThreshold());
    }

    @Override
    public void setRowIndexReadSizeWarnThreshold(String threshold)
    {
        DatabaseDescriptor.setRowIndexReadSizeWarnThreshold(parseDataStorageSpec(threshold));
    }

    @Override
    public String getRowIndexReadSizeAbortThreshold()
    {
        return toString(DatabaseDescriptor.getRowIndexReadSizeFailThreshold());
    }

    @Override
    public void setRowIndexReadSizeAbortThreshold(String threshold)
    {
        DatabaseDescriptor.setRowIndexReadSizeFailThreshold(parseDataStorageSpec(threshold));
    }

    private static String toString(DataStorageSpec value)
    {
        return value == null ? null : value.toString();
    }

    public void setDefaultKeyspaceReplicationFactor(int value)
    {
        DatabaseDescriptor.setDefaultKeyspaceRF(value);
        logger.info("set default keyspace rf to {}", value);
    }

    private static DataStorageSpec.LongBytesBound parseDataStorageSpec(String threshold)
    {
        return threshold == null
               ? null
               : new DataStorageSpec.LongBytesBound(threshold);
    }

    public int getDefaultKeyspaceReplicationFactor()
    {
        return DatabaseDescriptor.getDefaultKeyspaceRF();
    }

    public boolean getSkipPaxosRepairOnTopologyChange()
    {
        return DatabaseDescriptor.skipPaxosRepairOnTopologyChange();
    }

    public void setSkipPaxosRepairOnTopologyChange(boolean v)
    {
        DatabaseDescriptor.setSkipPaxosRepairOnTopologyChange(v);
        logger.info("paxos skip topology change repair {} via jmx", v ? "enabled" : "disabled");
    }

    public String getSkipPaxosRepairOnTopologyChangeKeyspaces()
    {
        return Joiner.on(',').join(DatabaseDescriptor.skipPaxosRepairOnTopologyChangeKeyspaces());
    }

    public void setSkipPaxosRepairOnTopologyChangeKeyspaces(String v)
    {
        DatabaseDescriptor.setSkipPaxosRepairOnTopologyChangeKeyspaces(v);
        logger.info("paxos skip topology change repair keyspaces set to  {} via jmx", v);
    }

    public boolean getPaxosAutoRepairsEnabled()
    {
        return PaxosState.uncommittedTracker().isAutoRepairsEnabled();
    }

    public void setPaxosAutoRepairsEnabled(boolean enabled)
    {
        PaxosState.uncommittedTracker().setAutoRepairsEnabled(enabled);
        logger.info("paxos auto repairs {} via jmx", enabled ? "enabled" : "disabled");
    }

    public boolean getPaxosStateFlushEnabled()
    {
        return PaxosState.uncommittedTracker().isStateFlushEnabled();
    }

    public void setPaxosStateFlushEnabled(boolean enabled)
    {
        PaxosState.uncommittedTracker().setStateFlushEnabled(enabled);
        logger.info("paxos state flush {} via jmx", enabled ? "enabled" : "disabled");
    }

    public List<String> getPaxosAutoRepairTables()
    {
        Set<TableId> tableIds = PaxosState.uncommittedTracker().tableIds();
        List<String> tables = new ArrayList<>(tableIds.size());
        for (TableId tableId : tableIds)
        {
            TableMetadata table = Schema.instance.getTableMetadata(tableId);
            if (table == null)
                continue;
            tables.add(table.keyspace + '.' + table.name);
        }
        return tables;
    }

    public long getPaxosPurgeGraceSeconds()
    {
        return DatabaseDescriptor.getPaxosPurgeGrace(SECONDS);
    }

    public void setPaxosPurgeGraceSeconds(long v)
    {
        DatabaseDescriptor.setPaxosPurgeGrace(v);
        logger.info("paxos purging grace seconds set to {} via jmx", v);
    }

    public String getPaxosOnLinearizabilityViolations()
    {
        return DatabaseDescriptor.paxosOnLinearizabilityViolations().toString();
    }

    public void setPaxosOnLinearizabilityViolations(String v)
    {
        DatabaseDescriptor.setPaxosOnLinearizabilityViolations(Config.PaxosOnLinearizabilityViolation.valueOf(v));
        logger.info("paxos on linearizability violations {} via jmx", v);
    }

    public String getPaxosStatePurging()
    {
        return DatabaseDescriptor.paxosStatePurging().name();
    }

    public void setPaxosStatePurging(String v)
    {
        DatabaseDescriptor.setPaxosStatePurging(PaxosStatePurging.valueOf(v));
        logger.info("paxos state purging {} via jmx", v);
    }

    public boolean getPaxosRepairEnabled()
    {
        return DatabaseDescriptor.paxosRepairEnabled();
    }

    public void setPaxosRepairEnabled(boolean enabled)
    {
        DatabaseDescriptor.setPaxosRepairEnabled(enabled);
        logger.info("paxos repair {} via jmx", enabled ? "enabled" : "disabled");
    }

    public boolean getPaxosDcLocalCommitEnabled()
    {
        return PaxosCommit.getEnableDcLocalCommit();
    }

    public void setPaxosDcLocalCommitEnabled(boolean enabled)
    {
        PaxosCommit.setEnableDcLocalCommit(enabled);
        logger.info("paxos dc local commit {} via jmx", enabled ? "enabled" : "disabled");
    }

    public String getPaxosBallotLowBound(String ksName, String tblName, String key)
    {
        Keyspace keyspace = Keyspace.open(ksName);
        if (keyspace == null)
            throw new IllegalArgumentException("Unknown keyspace '" + ksName + "'");

        ColumnFamilyStore cfs = keyspace.getColumnFamilyStore(tblName);
        if (cfs == null)
            throw new IllegalArgumentException("Unknown table '" + tblName + "' in keyspace '" + ksName + "'");

        TableMetadata table = cfs.metadata.get();
        DecoratedKey dk = table.partitioner.decorateKey(table.partitionKeyType.fromString(key));
        return cfs.getPaxosRepairHistory().ballotForToken(dk.getToken()).toString();
    }

    public Long getRepairRpcTimeout()
    {
        return DatabaseDescriptor.getRepairRpcTimeout(MILLISECONDS);
    }

    public void setRepairRpcTimeout(Long timeoutInMillis)
    {
        Preconditions.checkState(timeoutInMillis > 0);
        DatabaseDescriptor.setRepairRpcTimeout(timeoutInMillis);
        logger.info("RepairRpcTimeout set to {}ms via JMX", timeoutInMillis);
    }
    public void evictHungRepairs()
    {
        logger.info("StorageService#clearPaxosRateLimiters called via jmx");
        Paxos.evictHungRepairs();
    }

    public void clearPaxosRepairs()
    {
        logger.info("StorageService#clearPaxosRepairs called via jmx");
        PaxosTableRepairs.clearRepairs();
    }

    public void setSkipPaxosRepairCompatibilityCheck(boolean v)
    {
        PaxosRepair.setSkipPaxosRepairCompatibilityCheck(v);
        logger.info("SkipPaxosRepairCompatibilityCheck set to {} via jmx", v);
    }

    public boolean getSkipPaxosRepairCompatibilityCheck()
    {
        return PaxosRepair.getSkipPaxosRepairCompatibilityCheck();
    }

    @Override
    public boolean topPartitionsEnabled()
    {
        return DatabaseDescriptor.topPartitionsEnabled();
    }

    @Override
    public int getMaxTopSizePartitionCount()
    {
        return DatabaseDescriptor.getMaxTopSizePartitionCount();
    }

    @Override
    public void setMaxTopSizePartitionCount(int value)
    {
        DatabaseDescriptor.setMaxTopSizePartitionCount(value);
    }

    @Override
    public int getMaxTopTombstonePartitionCount()
    {
        return DatabaseDescriptor.getMaxTopTombstonePartitionCount();
    }

    @Override
    public void setMaxTopTombstonePartitionCount(int value)
    {
        DatabaseDescriptor.setMaxTopTombstonePartitionCount(value);
    }

    @Override
    public String getMinTrackedPartitionSize()
    {
        return DatabaseDescriptor.getMinTrackedPartitionSizeInBytes().toString();
    }

    @Override
    public void setMinTrackedPartitionSize(String value)
    {
        DatabaseDescriptor.setMinTrackedPartitionSizeInBytes(parseDataStorageSpec(value));
    }

    @Override
    public long getMinTrackedPartitionTombstoneCount()
    {
        return DatabaseDescriptor.getMinTrackedPartitionTombstoneCount();
    }

    @Override
    public void setMinTrackedPartitionTombstoneCount(long value)
    {
        DatabaseDescriptor.setMinTrackedPartitionTombstoneCount(value);
    }

    public void setSkipStreamDiskSpaceCheck(boolean value)
    {
        if (value != DatabaseDescriptor.getSkipStreamDiskSpaceCheck())
            logger.info("Changing skip_stream_disk_space_check from {} to {}", DatabaseDescriptor.getSkipStreamDiskSpaceCheck(), value);
        DatabaseDescriptor.setSkipStreamDiskSpaceCheck(value);
    }

    public boolean getSkipStreamDiskSpaceCheck()
    {
        return DatabaseDescriptor.getSkipStreamDiskSpaceCheck();
    }

    @Override
    public void removeNotificationListener(NotificationListener listener) throws ListenerNotFoundException
    {
        if (!skipNotificationListeners)
            super.removeNotificationListener(listener);
    }

    @Override
    public void removeNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) throws ListenerNotFoundException
    {
        if (!skipNotificationListeners)
            super.removeNotificationListener(listener, filter, handback);
    }

    @Override
    public void addNotificationListener(NotificationListener listener,
                                        NotificationFilter filter,
                                        Object handback) throws java.lang.IllegalArgumentException
    {
        if (!skipNotificationListeners)
            super.addNotificationListener(listener, filter, handback);
    }
}
