如何使用RMI配置Ehcache

Question

如果是这样，我有两个Web应用程序在两个不同的tomcats上运行，每个tomcat上都有两个应用程序。现在，要求应用于两个共享的tomcat ehcache缓存。

在一个tomcat中，这是配置：

<cacheManagerPeerProviderFactory
    class="net.sf.ehcache.distribution.RMICacheManagerPeerProviderFactory"
    properties="peerDiscovery=automatic, multicastGroupAddress=239.0.0.88,
    multicastGroupPort=4446, timeToLive=32"/>

<cacheManagerPeerListenerFactory
    class="net.sf.ehcache.distribution.RMICacheManagerPeerListenerFactory"
    properties="socketTimeoutMillis=10000"/>

另外一个tomcat，配置如下：

<cacheManagerPeerProviderFactory
    class="net.sf.ehcache.distribution.RMICacheManagerPeerProviderFactory"
    properties="peerDiscovery=automatic, multicastGroupAddress=239.0.0.81,
    multicastGroupPort=4440, timeToLive=32"/>

<cacheManagerPeerListenerFactory
    class="net.sf.ehcache.distribution.RMICacheManagerPeerListenerFactory"
    properties="socketTimeoutMillis=10000"/>

但是当tomcat启动时，会引发以下异常：

[2011-04-20 10:57:08] [INFO] [system.out] [10:57:08,676 WARN  [ehcache.distribution.RMIAsynchronousCacheReplicator] Unable to send message to remote peer.  Message was: null
java.util.ConcurrentModificationException
        at java.util.ArrayList.writeObject(ArrayList.java:573)
        at sun.reflect.GeneratedMethodAccessor195.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1469)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1400)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1518)
        at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:422)
        at net.sf.ehcache.Element.writeObject(Element.java:787)
        at sun.reflect.GeneratedMethodAccessor150.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1469)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1400)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:330)
        at net.sf.ehcache.distribution.EventMessage.writeObject(EventMessage.java:134)
        at sun.reflect.GeneratedMethodAccessor149.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1469)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1400)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:330)
        at java.util.ArrayList.writeObject(ArrayList.java:570)
        at sun.reflect.GeneratedMethodAccessor195.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1469)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1400)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:330)
        at sun.rmi.server.UnicastRef.marshalValue(UnicastRef.java:274)
        at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:133)
        at net.sf.ehcache.distribution.RMICachePeer_Stub.send(Unknown Source)
        at net.sf.ehcache.distribution.RMIAsynchronousCacheReplicator.flushReplicationQueue(RMIAsynchronousCacheReplicator.java:317)
        at net.sf.ehcache.distribution.RMIAsynchronousCacheReplicator.replicationThreadMain(RMIAsynchronousCacheReplicator.java:119)
        at net.sf.ehcache.distribution.RMIAsynchronousCacheReplicator.access$100(RMIAsynchronousCacheReplicator.java:56)
        at net.sf.ehcache.distribution.RMIAsynchronousCacheReplicator$ReplicationThread.run(RMIAsynchronousCacheReplicator.java:376)
]