I have updated to release 1.0.1 since 1.0.0 has OOM issue.

I set up cluster which have four brokers. 

There are about 150 topics, and about total 4000 partitions, ReplicationFactor is 2.  

connctors are used to write/read data to/from brokers.  

connecotr version is 0.10.1.  

The average message size is 500B, and around 60000 messages per seconds.  

one of the broker keep report OOM, and can't handle request like: 

```

    [2018-03-24 12:37:17,449] ERROR [KafkaApi-1001] Error when handling request {replica_id=-1,max_wait_time=500,min_bytes=1,topics=[{topic=voltetraffica.data,partitions=[
    {partition=16,fetch_offset=51198,max_bytes=60728640} ,{partition=12,fetch_offset=50984,max_bytes=60728640}]}]} (kafka.server.KafkaApis)
    java.lang.OutOfMemoryError: Java heap space
    at java.nio.HeapByteBuffer.(HeapByteBuffer.java:57)
    at java.nio.ByteBuffer.allocate(ByteBuffer.java:335)
    at org.apache.kafka.common.record.AbstractRecords.downConvert(AbstractRecords.java:101)
    at org.apache.kafka.common.record.FileRecords.downConvert(FileRecords.java:253)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$convertedPartitionData$1$1$$anonfun$apply$4.apply(KafkaApis.scala:525)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$convertedPartitionData$1$1$$anonfun$apply$4.apply(KafkaApis.scala:523)
    at scala.Option.map(Option.scala:146)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$convertedPartitionData$1$1.apply(KafkaApis.scala:523)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$convertedPartitionData$1$1.apply(KafkaApis.scala:513)
    at scala.Option.flatMap(Option.scala:171)
    at kafka.server.KafkaApis.kafka$server$KafkaApis$$convertedPartitionData$1(KafkaApis.scala:513)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$createResponse$2$1.apply(KafkaApis.scala:561)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$createResponse$2$1.apply(KafkaApis.scala:560)
    at scala.collection.Iterator$class.foreach(Iterator.scala:891)
    at scala.collection.AbstractIterator.foreach(Iterator.scala:1334)
    at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
    at scala.collection.AbstractIterable.foreach(Iterable.scala:54)
    at kafka.server.KafkaApis.kafka$server$KafkaApis$$createResponse$2(KafkaApis.scala:560)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$fetchResponseCallback$1$1.apply(KafkaApis.scala:574)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$fetchResponseCallback$1$1.apply(KafkaApis.scala:574)
    at kafka.server.KafkaApis$$anonfun$sendResponseMaybeThrottle$1.apply$mcVI$sp(KafkaApis.scala:2041)
    at kafka.server.ClientRequestQuotaManager.maybeRecordAndThrottle(ClientRequestQuotaManager.scala:54)
    at kafka.server.KafkaApis.sendResponseMaybeThrottle(KafkaApis.scala:2040)
    at kafka.server.KafkaApis.kafka$server$KafkaApis$$fetchResponseCallback$1(KafkaApis.scala:574)
    at kafka.server.KafkaApis$$anonfun$kafka$server$KafkaApis$$processResponseCallback$1$1.apply$mcVI$sp(KafkaApis.scala:593)
    at kafka.server.ClientQuotaManager.maybeRecordAndThrottle(ClientQuotaManager.scala:176)
    at kafka.server.KafkaApis.kafka$server$KafkaApis$$processResponseCallback$1(KafkaApis.scala:592)
    at kafka.server.KafkaApis$$anonfun$handleFetchRequest$4.apply(KafkaApis.scala:609)
    at kafka.server.KafkaApis$$anonfun$handleFetchRequest$4.apply(KafkaApis.scala:609)
    at kafka.server.ReplicaManager.fetchMessages(ReplicaManager.scala:820)
    at kafka.server.KafkaApis.handleFetchRequest(KafkaApis.scala:601)
    at kafka.server.KafkaApis.handle(KafkaApis.scala:99)

```

and then lots of shrink ISR ( this broker is 1001)

```

    018-03-24 13:43:00,285] INFO [Partition gnup.source.offset.storage.topic-5 broker=1001] Shrinking ISR from 1001,1002 to 1001 (kafka.cluster.Partition)  

    018-03-24 13:43:00,286] INFO [Partition s1mme.data-72 broker=1001] Shrinking ISR from 1001,1002 to 1001 (kafka.cluster.Partition)  

    018-03-24 13:43:00,286] INFO [Partition gnup.sink.status.storage.topic-17 broker=1001] Shrinking ISR from 1001,1002 to 1001 (kafka.cluster.Partition)  

    018-03-24 13:43:00,287] INFO [Partition probessgsniups.sink.offset.storage.topic-4 broker=1001] Shrinking ISR from 1001,1002 to 1001 (kafka.cluster.Partition)  

    018-03-24 13:43:01,447] INFO [GroupCoordinator 1001]: Stabilized group connect-VOICE_1_SINK_CONN generation 26 (__consumer_offsets-18) (kafka.coordinator.group.GroupCoordinator)  

```

i can't dump the heap since each time I run:  

[root@sslave1 kafka]# jcmd 55409 GC.heap\_dump /home/ngdb/heap\_dump175.hprof  

55409: 

```

    com.sun.tools.attach.AttachNotSupportedException: Unable to open socket file: target process not responding or HotSpot VM not loaded  
    at sun.tools.attach.LinuxVirtualMachine.(LinuxVirtualMachine.java:106)
    at  sun.tools.attach.LinuxAttachProvider.attachVirtualMachine(LinuxAttachProvider.java:63)
    at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:208)
    at sun.tools.jcmd.JCmd.executeCommandForPid(JCmd.java:147)
    at sun.tools.jcmd.JCmd.main(JCmd.java:131)

```

the JVM parameter is:

```

    -XX:+ExplicitGCInvokesConcurrent -XX:GCLogFileSize=104857600 -XX:InitialHeapSize=2147483648 -XX:InitiatingHeapOccupancyPercent=35  -XX:+ManagementServer -XX:MaxGCPauseMillis=20 -XX:MaxHeapSize=4294967296   -XX:NumberOfGCLogFiles=10 -XX:+PrintGC -XX:+PrintGCDateStamps   -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+UseCompressedClassPointers   -XX:+UseCompressedOops -XX:+UseG1GC -XX:+UseGCLogFileRotation

```

when I use -XX:mx=2G, four brokers reported OOM,  

after i increated it to 4G, only one brokers reported OOM.  

Ticker is also raised in <https://issues.apache.org/jira/browse/KAFKA-6709>.