text: import time
  import pytest
  from helpers.cluster import ClickHouseCluster
  from helpers.test_tools import assert_eq_with_retry
  
  from helpers.client import QueryRuntimeException
  
  cluster = ClickHouseCluster(__file__)
  node1 = cluster.add_instance('node1', main_configs=["configs/config.d/clusters.xml"], user_configs=["configs/users.d/default_with_password.xml"], with_zookeeper=True)
  node2 = cluster.add_instance('node2', main_configs=["configs/config.d/clusters.xml"], user_configs=["configs/users.d/default_with_password.xml"], with_zookeeper=True)
  node3 = cluster.add_instance('node3', main_configs=["configs/config.d/clusters.xml"], user_configs=["configs/users.d/default_with_password.xml"], with_zookeeper=True)
  node4 = cluster.add_instance('node4', main_configs=["configs/config.d/clusters.xml"], user_configs=["configs/users.d/default_with_password.xml"], with_zookeeper=True)
  node5 = cluster.add_instance('node5', main_configs=["configs/config.d/clusters.xml"], user_configs=["configs/users.d/default_with_password.xml"], with_zookeeper=True)
  node6 = cluster.add_instance('node6', main_configs=["configs/config.d/clusters.xml"], user_configs=["configs/users.d/default_with_password.xml"], with_zookeeper=True)
  
  
  @pytest.fixture(scope="module")
  def start_cluster():
      try:
          cluster.start()
  
          for node, shard in [(node1, 1), (node2, 1), (node3, 2), (node4, 2), (node5, 3), (node6, 3)]:
              node.query(
              '''
                  CREATE TABLE test_table(date Date, id UInt32, dummy UInt32)
                  ENGINE = ReplicatedMergeTree('/clickhouse/tables/test{shard}/replicated', '{replica}')
                  PARTITION BY date
                  ORDER BY id
              '''.format(shard=shard, replica=node.name), settings={"password": "clickhouse"})
  
          yield cluster
  
      finally:
          cluster.shutdown()
  
  def test_truncate(start_cluster):
      node1.query("insert into test_table values ('2019-02-15', 1, 2), ('2019-02-15', 2, 3), ('2019-02-15', 3, 4)", settings={"password": "clickhouse"})
  
      assert node1.query("select count(*) from test_table", settings={"password": "clickhouse"}) == "3\n"
      node2.query("system sync replica test_table", settings={"password": "clickhouse"})
      assert node2.query("select count(*) from test_table", settings={"password": "clickhouse"}) == "3\n"
  
  
      node3.query("insert into test_table values ('2019-02-16', 1, 2), ('2019-02-16', 2, 3), ('2019-02-16', 3, 4)", settings={"password": "clickhouse"})
  
      assert node3.query("select count(*) from test_table", settings={"password": "clickhouse"}) == "3\n"
      node4.query("system sync replica test_table", settings={"password": "clickhouse"})
      assert node4.query("select count(*) from test_table", settings={"password": "clickhouse"}) == "3\n"
  
      node3.query("truncate table test_table on cluster 'awesome_cluster'", settings={"password": "clickhouse"})
  
      for node in [node1, node2, node3, node4]:
          assert_eq_with_retry(node, "select count(*) from test_table", "0", settings={"password": "clickhouse"})
  
      node2.query("drop table test_table on cluster 'awesome_cluster'", settings={"password": "clickhouse"})
  
      for node in [node1, node2, node3, node4]:
          assert_eq_with_retry(node, "select count(*) from system.tables where name='test_table'", "0", settings={"password": "clickhouse"})
  
  def test_alter(start_cluster):
      node5.query("insert into test_table values ('2019-02-15', 1, 2), ('2019-02-15', 2, 3), ('2019-02-15', 3, 4)", settings={"password": "clickhouse"})
      node6.query("insert into test_table values ('2019-02-15', 4, 2), ('2019-02-15', 5, 3), ('2019-02-15', 6, 4)", settings={"password": "clickhouse"})
  
      node5.query("SYSTEM SYNC REPLICA test_table", settings={"password": "clickhouse"})
      node6.query("SYSTEM SYNC REPLICA test_table", settings={"password": "clickhouse"})
  
      assert_eq_with_retry(node5, "select count(*) from test_table", "6", settings={"password": "clickhouse"})
      assert_eq_with_retry(node6, "select count(*) from test_table", "6", settings={"password": "clickhouse"})
  
      node6.query("OPTIMIZE TABLE test_table ON CLUSTER 'simple_cluster' FINAL", settings={"password": "clickhouse"})
  
      node5.query("SYSTEM SYNC REPLICA test_table", settings={"password": "clickhouse"})
      node6.query("SYSTEM SYNC REPLICA test_table", settings={"password": "clickhouse"})
  
      assert_eq_with_retry(node5, "select count(*) from test_table", "6", settings={"password": "clickhouse"})
      assert_eq_with_retry(node6, "select count(*) from test_table", "6", settings={"password": "clickhouse"})
  
      node6.query("ALTER TABLE test_table ON CLUSTER 'simple_cluster' DETACH PARTITION '2019-02-15'", settings={"password": "clickhouse"})
      assert_eq_with_retry(node5, "select count(*) from test_table", "0", settings={"password": "clickhouse"})
      assert_eq_with_retry(node6, "select count(*) from test_table", "0", settings={"password": "clickhouse"})
  
      with pytest.raises(QueryRuntimeException):
          node6.query("ALTER TABLE test_table ON CLUSTER 'simple_cluster' ATTACH PARTITION '2019-02-15'", settings={"password": "clickhouse"})
  
      node5.query("ALTER TABLE test_table ATTACH PARTITION '2019-02-15'", settings={"password": "clickhouse"})
  
      assert_eq_with_retry(node5, "select count(*) from test_table", "6", settings={"password": "clickhouse"})
      assert_eq_with_retry(node6, "select count(*) from test_table", "6", settings={"password": "clickhouse"})
  
      node5.query("ALTER TABLE test_table ON CLUSTER 'simple_cluster' MODIFY COLUMN dummy String", settings={"password": "clickhouse"})
  
      assert_eq_with_retry(node5, "select length(dummy) from test_table ORDER BY dummy LIMIT 1", "1", settings={"password": "clickhouse"})
      assert_eq_with_retry(node6, "select length(dummy) from test_table ORDER BY dummy LIMIT 1", "1", settings={"password": "clickhouse"})
  
      node6.query("ALTER TABLE test_table ON CLUSTER 'simple_cluster' DROP PARTITION '2019-02-15'", settings={"password": "clickhouse"})
  
      assert_eq_with_retry(node5, "select count(*) from test_table", "0", settings={"password": "clickhouse"})
      assert_eq_with_retry(node6, "select count(*) from test_table", "0", settings={"password": "clickhouse"})
  