[infinispan-dev] NPE from invokeRemotely on stopped cache

[Manik Surtani]

On 26 Jul 2010, at 09:33, Galder Zamarreño wrote:

> Looks to me that this is an issue with stoppage priorities. ReplicationQueue.stop() should happen before JGroupsTransport.stop()
> 
> At the moment, both @Stop methods are defined without priority (JGroupsTransport's @Stop is on Transport interface), so they assumed default which is 10.
> 
> It's unclear from @Stop how the priorities work (javadoc needs to be clearer cos at the moment it's a copy/paste of @Start), but I think (without looking at the code) that higher priorities (= lower numbers) would be stopped first.
> 
> So, you could try setting RQ's stop to 9 and @Stop in transport to 10 (default) and  and see if it works.

+1, that should do it for you.

> 
> On Jul 25, 2010, at 7:15 PM, Sanne Grinovero wrote:
> 
>> Hello,
>> I got the following stacktrace using CR2:
>>    [exec] java.lang.NullPointerException
>>    [exec] 	at
>> org.infinispan.remoting.rpc.RpcManagerImpl.invokeRemotely(RpcManagerImpl.java:92)
>>    [exec] 	at
>> org.infinispan.remoting.rpc.RpcManagerImpl.invokeRemotely(RpcManagerImpl.java:128)
>>    [exec] 	at
>> org.infinispan.remoting.ReplicationQueue.flush(ReplicationQueue.java:147)
>>    [exec] 	at
>> org.infinispan.remoting.ReplicationQueue$1.run(ReplicationQueue.java:99)
>>    [exec] 	at
>> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
>>    [exec] 	at
>> java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317)
>>    [exec] 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)
>>    [exec] 	at
>> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$101(ScheduledThreadPoolExecutor.java:98)
>>    [exec] 	at
>> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.runPeriodic(ScheduledThreadPoolExecutor.java:181)
>>    [exec] 	at
>> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:205)
>>    [exec] 	at
>> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>>    [exec] 	at
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>>    [exec] 	at java.lang.Thread.run(Thread.java:619)
>> 
>>> From which I went to inspect
>> org.infinispan.remoting.transport.jgroups.JGroupsTransport; in this
>> class the "members" field is initialized as Collections.emptyList()
>> and it appears that the only way to become null is by stopping the
>> cache.
>> Also it seems that in many points the check "members!=null" is
>> performed, but not in RpcManagerImpl.
>> 
>> Could the stop() method be changed to set this value to emptyList()
>> too, so that all those "!=null" checks could be avoided, or if you see
>> good reasons to throw an error then what would be a better one than
>> NPE.
>> 
>> I'm also wondering if this is supposed to happen: isn't this a race
>> condition during the stop process of the cache? I'd like to stop it
>> after all replications have been sent, seems cleaner.
>> 
>> Regards,
>> Sanne
>> _______________________________________________
>> infinispan-dev mailing list
>> infinispan-dev at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
> 
> --
> Galder Zamarreño
> Sr. Software Engineer
> Infinispan, JBoss Cache
> 
> 
> _______________________________________________
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> infinispan-dev at lists.jboss.org
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--
Manik Surtani
manik at jboss.org
Lead, Infinispan
Lead, JBoss Cache
http://www.infinispan.org
http://www.jbosscache.org