[jira] [Commented] (FLINK-10960) CEP: Job Failure when .times(2) is used

["sophie (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-10960?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17006911#comment-17006911 ] 

sophie commented on FLINK-10960:
--------------------------------

So has the root cause of this strange bug been found and fixed?  Or need we still do the same workaround ? To avoid restoring into a smaller state? Thx.

> CEP: Job Failure when .times(2) is used
> ---------------------------------------
>
>                 Key: FLINK-10960
>                 URL: https://issues.apache.org/jira/browse/FLINK-10960
>             Project: Flink
>          Issue Type: Bug
>          Components: Library / CEP
>    Affects Versions: 1.6.2
>            Reporter: Thomas Wozniakowski
>            Priority: Critical
>
> Hi Guys,
> Encountered a strange one today. We use the CEP library in a configurable way where we plug a config file into the Flink Job JAR and it programmatically sets up a bunch of CEP operators matching the config file.
> I encountered a strange bug when I was testing with some artificially low numbers in our testing environment today. The CEP code we're using (modified slightly) is:
> {code:java}
> Pattern.begin(EVENT_SEQUENCE, AfterMatchSkipStrategy.skipPastLastEvent())
>             .times(config.getNumberOfUniqueEvents())
>             .where(uniquenessCheckOnAlreadyMatchedEvents())
>             .within(seconds(config.getWithinSeconds()));
> {code}
> When using the {{numberOfUniqueEvents: 2}}, I started seeing the following error killing the job whenever a match was detected:
> {quote}
> ava.lang.RuntimeException: Exception occurred while processing valve output watermark: 
> 	at org.apache.flink.streaming.runtime.io.StreamInputProcessor$ForwardingValveOutputHandler.handleWatermark(StreamInputProcessor.java:265)
> 	at org.apache.flink.streaming.runtime.streamstatus.StatusWatermarkValve.findAndOutputNewMinWatermarkAcrossAlignedChannels(StatusWatermarkValve.java:189)
> 	at org.apache.flink.streaming.runtime.streamstatus.StatusWatermarkValve.inputWatermark(StatusWatermarkValve.java:111)
> 	at org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:184)
> 	at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:105)
> 	at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:300)
> 	at org.apache.flink.runtime.taskmanager.Task.run(Task.java:711)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.flink.util.FlinkRuntimeException: State eventSequence:2 does not exist in the NFA. NFA has states [Final State $endState$ [
> ]), Normal State eventSequence [
> 	StateTransition(TAKE, from eventSequenceto $endState$, with condition),
> 	StateTransition(IGNORE, from eventSequenceto eventSequence, with condition),
> ]), Start State eventSequence:0 [
> 	StateTransition(TAKE, from eventSequence:0to eventSequence, with condition),
> ])]
> 	at org.apache.flink.cep.nfa.NFA.isStartState(NFA.java:144)
> 	at org.apache.flink.cep.nfa.NFA.isStateTimedOut(NFA.java:270)
> 	at org.apache.flink.cep.nfa.NFA.advanceTime(NFA.java:244)
> 	at org.apache.flink.cep.operator.AbstractKeyedCEPPatternOperator.advanceTime(AbstractKeyedCEPPatternOperator.java:389)
> 	at org.apache.flink.cep.operator.AbstractKeyedCEPPatternOperator.onEventTime(AbstractKeyedCEPPatternOperator.java:293)
> 	at org.apache.flink.streaming.api.operators.InternalTimerServiceImpl.advanceWatermark(InternalTimerServiceImpl.java:251)
> 	at org.apache.flink.streaming.api.operators.InternalTimeServiceManager.advanceWatermark(InternalTimeServiceManager.java:128)
> 	at org.apache.flink.streaming.api.operators.AbstractStreamOperator.processWatermark(AbstractStreamOperator.java:746)
> 	at org.apache.flink.streaming.runtime.io.StreamInputProcessor$ForwardingValveOutputHandler.handleWatermark(StreamInputProcessor.java:262)
> {quote}
> Changing the config to {{numberOfUniqueEvents: 3}} fixed the problem. Changing it back to 2 brought the problem back. It seems to be specifically related to the value of 2.
> This is not a blocking issue for me because we typically use much higher numbers than this in production anyway, but I figured you guys might want to know about this issue.
> Let me know if you need any more information.
> Tom



--
This message was sent by Atlassian Jira
(v8.3.4#803005)