Storm - java.util.ConcurrentModificationException

[Manikandan <ma...@gmail.com>]

> I am facing the following issue with the DRPC topology.
> The DRPC topology is called repeatedly every 10 minutes. This issue occurs
> in one of the runs and the couple of calls later, it started to work
> without any issues.
>
> What could be the possible root causes?
>
> Storm Version : 0.8.2
>
> Here is the entire stack trace,
>
> java.lang.RuntimeException: java.util.ConcurrentModificationException
>  at
> backtype.storm.utils.DisruptorQueue.consumeBatchToCursor(DisruptorQueue.java:87)
> at
> backtype.storm.utils.DisruptorQueue.consumeBatchWhenAvailable(DisruptorQueue.java:58)
>  at
> backtype.storm.disruptor$consume_batch_when_available.invoke(disruptor.clj:62)
> at
> backtype.storm.daemon.executor$fn__4050$fn__4059$fn__4106.invoke(executor.clj:658)
>  at backtype.storm.util$async_loop$fn__465.invoke(util.clj:377)
> at clojure.lang.AFn.run(AFn.java:24)
> at java.lang.Thread.run(Thread.java:662)
> Caused by: java.util.ConcurrentModificationException
> at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
> at java.util.HashMap$EntryIterator.next(HashMap.java:834)
>  at java.util.HashMap$EntryIterator.next(HashMap.java:832)
> at java.util.AbstractMap.equals(AbstractMap.java:420)
>  at java.util.HashMap.getEntry(HashMap.java:349)
> at java.util.HashMap.containsKey(HashMap.java:335)
> at backtype.storm.utils.*TimeCacheMap.get(TimeCacheMap.java:100)*
>  at
> backtype.storm.coordination.CoordinatedBolt$CoordinatedOutputCollector.updateTaskCounts(CoordinatedBolt.java:117)
> at
> backtype.storm.coordination.CoordinatedBolt$CoordinatedOutputCollector.emit(CoordinatedBolt.java:75)
>  at backtype.storm.task.OutputCollector.emit(OutputCollector.java:186)
> at backtype.storm.task.OutputCollector.emit(OutputCollector.java:46)
>  at backtype.storm.task.OutputCollector.emit(OutputCollector.java:84)
>         ...........................
>
> Thanks
> Manikandan
>