[infinispan-dev] NPE from invokeRemotely on stopped cache

[Galder Zamarreño]

On Jul 26, 2010, at 5:37 PM, Sanne Grinovero wrote:

> 2010/7/26 Manik Surtani <manik at jboss.org>:
>> 
>> 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.
>> 
> 
> Thanks for all answers,
> I'm trying it but as the exception was showing up very occasionally I
> can't tell you if it's fixed (I might be able to tell that it's not
> fixed).
> Shouldn't this change be applied ? (shall I open an issue?)

Yes please, open an issue for this. If you don't have time to deal with it, feel free to assign it to myself.

> Sanne
> 
> 
>>> 
>>> 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
>>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
>> 
>> --
>> Manik Surtani
>> manik at jboss.org
>> Lead, Infinispan
>> Lead, JBoss Cache
>> http://www.infinispan.org
>> http://www.jbosscache.org
>> 
>> 
>> 
>> 
>> 
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>> 
> 
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--
Galder Zamarreño
Sr. Software Engineer
Infinispan, JBoss Cache