Hazelcast集群成员由于大量“isStillRunningService”对象而内存不足

Question

我们有一个在3.5版本上利用Hazelcast IExecutor服务和IMap的系统。我们最近遇到了Hazelcast集群成员在生产中内存不足的情况，一个接一个，最后所有节点都被OOM崩溃。
在进行原因分析时，我们发现下面有数千个日志条目，日志文件大小呈指数级增长。存放原木的存储空间也已经用完。

WARNING: [10.7.90.189]:30103 [FB] [3.5] Asking if operation execution has been started: com.hazelcast.spi.impl.operationservice.impl.IsStillRunningService$InvokeIsStillRunningOperationRunnable@48b3ac3b
Mar 30, 2016 11:09:29 AM com.hazelcast.spi.impl.operationservice.impl.Invocation
WARNING: [10.7.90.189]:30103 [FB] [3.5] While asking 'is-executing': Invocation{ serviceName='hz:core:partitionService', op=com.hazelcast.spi.impl.operationservice.impl.operations.IsStillExecutingOperation{serviceName='hz:core:partition
Service', partitionId=-1, callId=59834, invocationTime=1459349279980, waitTimeout=-1, callTimeout=5000}, partitionId=-1, replicaIndex=0, tryCount=0, tryPauseMillis=0, invokeCount=1, callTimeout=5000, target=Address[1.2.3.4]:30102, b
ackupsExpected=0, backupsCompleted=0}
com.hazelcast.core.OperationTimeoutException: No response for 10000 ms. Aborting invocation! Invocation{ serviceName='hz:core:partitionService', op=com.hazelcast.spi.impl.operationservice.impl.operations.IsStillExecutingOperation{servic
eName='hz:core:partitionService', partitionId=-1, callId=268177, invocationTime=1459349295209, waitTimeout=-1, callTimeout=5000}, partitionId=-1, replicaIndex=0, tryCount=0, tryPauseMillis=0, invokeCount=1, callTimeout=5000, target=Addr
ess[10.7.90.190]:30102, backupsExpected=0, backupsCompleted=0} No response has been received!  backups-expected:0 backups-completed: 0
        at com.hazelcast.spi.impl.operationservice.impl.Invocation.newOperationTimeoutException(Invocation.java:491)
        at com.hazelcast.spi.impl.operationservice.impl.IsStillRunningService$IsOperationStillRunningCallback.setOperationTimeout(IsStillRunningService.java:224)
        at com.hazelcast.spi.impl.operationservice.impl.IsStillRunningService$IsOperationStillRunningCallback.onFailure(IsStillRunningService.java:219)
        at com.hazelcast.spi.impl.operationservice.impl.InvocationFuture$1.run(InvocationFuture.java:137)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
        at com.hazelcast.util.executor.HazelcastManagedThread.executeRun(HazelcastManagedThread.java:76)
        at com.hazelcast.util.executor.HazelcastManagedThread.run(HazelcastManagedThread.java:92)

我知道，集群成员会不断发出心跳，以确保所有成员都活着，我相信默认值是10sec。现在的问题是，如果任何一个成员没有响应或处于休状态，其余的成员将继续进行is执行调用。在查看了堆转储之后，才知道>73%的堆中充满了“isStillRunningService”对象。

问题：

1. 如何知道到底出了什么问题？
2. 存储空间耗尽只是一种巧合还是可能有任何关联？我们怀疑，一个星期内发生了两次。

<hazelcast xsi:schemaLocation="http://www.hazelcast.com/schema/config http://www.hazelcast.com/schema/config/hazelcast-config-3.5.xsd"
           xmlns="http://www.hazelcast.com/schema/config"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    <map name="myMap">
        <backup-count>0</backup-count>
        <time-to-live-seconds>43200</time-to-live-seconds>
        <eviction-policy>LRU</eviction-policy>
        <max-size policy="USED_HEAP_PERCENTAGE">75</max-size>
        <eviction-percentage>10</eviction-percentage>
        <in-memory-format>OBJECT</in-memory-format>
    </map>

    <executor-service name="calculation">
            <pool-size>10</pool-size>
        <queue-capacity>400</queue-capacity>
    </executor-service>

    <executor-service name="loader">
            <pool-size>5</pool-size>
        <queue-capacity>400</queue-capacity>
    </executor-service>

    <properties>
        <property name="hazelcast.icmp.timeout">5000</property>
        <property name="hazelcast.initial.wait.seconds">10</property>
        <property name="hazelcast.connection.monitor.interval">5000</property>
    </properties>

    <network>
        <port auto-increment="true" port-count="100">30101</port>
        <join>
            <multicast enabled="false">
                <multicast-group>224.2.2.3</multicast-group>
                <multicast-port>54327</multicast-port>
            </multicast>
            <tcp-ip enabled="true">
                <interface>1.2.3.4</interface>
                <interface>1.2.3.5</interface>
                <interface>1.2.3.6</interface>
            </tcp-ip>
            <aws enabled="false"/>
        </join>
        <interfaces enabled="false">
            <interface>127.0.0.1</interface>
        </interfaces>
    </network>
</hazelcast>

Answer 1

你能升级到3.6吗。添加了一些补丁，以防止使用is-stily-running运行到OOME。在3.7中，整个机制将被移除，取而代之的是一种问题较少的方法。

https://github.com/hazelcast/hazelcast/pull/7719