Re: [javagroups-users] Memory Leak in JGroups 3.1.0.FINAL?

[Bela B. <be...@ya...>]

I've recently changed the way the JGroups 'top' (global) ThreadGroup is 
created and destroyed, so perhaps this is a result of it. I'll take a 
look... can you create a JIRA and attach the dump ?

On 7/19/12 5:45 PM, Romain Colle wrote:
> Hi all,
>
> While trying to upgrade our application from JGroups 3.0.6.FINAL to
> 3.1.0.FINAL, we've witnessed a fairly large memory leak in our test suite.
>
> Looking at a heapdump in JProfiler, we can see that the following chain
> retains the memory that should have been garbage-collected:
>
> java.lang.ThreadGroup (groups)
> -->  org.jgroups.protocol.TP$1 (element)
> ---->  org.jgroups.protocol.UDP (this$0)
> ------>  org.jgroups.stacks.ProtocolStack (stack)
> -------->  org.jgroups.JChannel (channel)
> ---------->  org.jgroups.blocks.MessageDispatcher$ProtocolAdapter
> (up_handler)
> ------------>
> com.quartetfs.tech.distribution.messenger.impl.QFSMessageDispatcher (this$0)
>
> The QFSMessageDispatcher is a simple extension
> of org.jgroups.blocks.MessageDispatcher that holds references to some
> fairly large objects in the application.
> Even though the channel has been closed and all the JGroups threads have
> disappeared from the JVM, it is not being garbage-collected because of this
> reference chain.
>
> As this problem does not appear in the 3.0.x branch, I'm assuming this is
> related to the new version of JGroups.
> Could you please confirm this is the case? I have the full heap dump
> available if needed.
>
> Thanks a lot!


-- 
Bela Ban, JGroups lead (http://www.jgroups.org)