java.io.NotSerializableException while writing to Oracle Coherence cache

Question

I have 2 storage enabled cache nodes that i am trying to use for pre-loading of cache. About 1 million accounts are to be loaded by these 2 storage enabled nodes. Both key and value are String objects which I am trying to write to cache. I am using InvocationService.execute() method to invoke the pre-loading tasks asynchronously:

for (Map.Entry<Member, LoaderInvocable> entry : mappedWork.entrySet()) {
    Member member = entry.getKey();
    LoaderInvocable task = entry.getValue();
    invocationService.execute(task, Collections.singleton(member), null);
}

LoaderInvocable is a class that is implementing Invocable and Serializable interfaces and its run() method has been overridden to performs the actual work of reading from database and writing to the cache.

InvocationService is defined as below in the coherence config file:

<invocation-scheme>
      <scheme-name>
      InvocationScheme</scheme-name>
      <service-name>
      LoaderInvocationService</service-name>
      <autostart system-property="tangosol.coherence.invocation.autostart">true</autostart>
 </invocation-scheme>

Below is the exception that i am getting:

2016-02-22 17:16:24,612 [pool-1-thread-1] ERROR (support.context.SessionExecutable) Caught exception from SessionExecutable.execute()
(Wrapped) java.io.NotSerializableException: com.oracle.common.collections.ConcurrentLinkedQueue
    at com.tangosol.util.Base.ensureRuntimeException(Base.java:289)
    at com.tangosol.util.Base.ensureRuntimeException(Base.java:270)
    at com.tangosol.coherence.component.util.daemon.queueProcessor.packetProcessor.PacketPublisher.packetizeMessage(PacketPublisher.CDB:28)
    at com.tangosol.coherence.component.util.daemon.queueProcessor.packetProcessor.PacketPublisher$InQueue.add(PacketPublisher.CDB:8)
    at com.tangosol.coherence.component.util.daemon.queueProcessor.packetProcessor.PacketPublisher.post(PacketPublisher.CDB:1)
    at com.tangosol.coherence.component.net.Message.dispatch(Message.CDB:77)
    at com.tangosol.coherence.component.net.Message.post(Message.CDB:1)
    at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid.post(Grid.CDB:2)
    at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid.send(Grid.CDB:1)
    at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.InvocationService.execute(InvocationService.CDB:33)
    at com.tangosol.coherence.component.util.safeService.SafeInvocationService.execute(SafeInvocationService.CDB:1)

. . . . . .

Caused by: java.io.NotSerializableException: com.oracle.common.collections.ConcurrentLinkedQueue
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1180)
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
    at java.util.Hashtable.writeObject(Hashtable.java:988)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:975)
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
    at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:438)
    at com.tangosol.coherence.Component.writeObject(Component.CDB:1)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:975)
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
    at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:438)
    at com.tangosol.coherence.Component.writeObject(Component.CDB:1)

It seems that half of the accounts have been cached successfully. Can it be node specific issue? Both of the storage enabled cache nodes are on the same server using the same cluster configuration. From the logs it is clear that both nodes successfully joined the cluster.

Even on the same server, the invocable is going to travel over the network from 1 node to the other and therefore needs to be serializable. — Paul Creasey, Feb 23 '16 at 15:14
My LoaderInvocable class is already Serializable, Paul. Still getting the error. Even the objects that i am storing in the cache, is String only which is implicitly serializable. — Sachin Bansal, Feb 24 '16 at 06:33
Please check your LoaderInvocable class implements PofSerializer — Praveen Kumar K S, Feb 24 '16 at 12:24
Thanks Praveen. I have used the POF serializer and not facing the exception anymore. But now i am facing a new problem. — Sachin Bansal, Feb 25 '16 at 07:27

score 0 · Answer 1 · edited Oct 11 '16 at 12:44

Thanks Praveen. I have implemented the PortableObject interface and not facing the NotSerializableException anymore. But now i am facing a new problem. The second node is not invoking the task and leaving the cluster without any exception in the logs.

I used the InvocationObserver which suggests that memberLeft() the cluster. Can it be something wrong with my implementation of readExternal() and writeExternal() methods for serialization? Below is the implementation:

@Override
public void readExternal(PofReader paramPofReader) throws IOException {
    // TODO Auto-generated method stub

    cacheName = paramPofReader.readString(0);
    firstRow = paramPofReader.readLong(1);
    lastRow = paramPofReader.readLong(2);

}

@Override
public void writeExternal(PofWriter paramPofWriter) throws IOException {
    // TODO Auto-generated method stub
    paramPofWriter.writeString(0, cacheName);
    paramPofWriter.writeLong(1, firstRow);
    paramPofWriter.writeLong(2, lastRow);
}

java.io.NotSerializableException while writing to Oracle Coherence cache

1 Answers1