flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Paolo Rendano (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (FLINK-7606) CEP operator leaks state
Date Thu, 05 Oct 2017 13:42:00 GMT

    [ https://issues.apache.org/jira/browse/FLINK-7606?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16192891#comment-16192891

Paolo Rendano commented on FLINK-7606:

HI [~kkl0u],
1) exactly
2) exactly, but my stream is a never ending stream, so I cannot close. The idea could be,
why do not flush automatically the buffer not only on a memory use base but also after a configurable
timeout? Could be a good enhancement to implement for different use cases.


> CEP operator leaks state
> ------------------------
>                 Key: FLINK-7606
>                 URL: https://issues.apache.org/jira/browse/FLINK-7606
>             Project: Flink
>          Issue Type: Bug
>          Components: CEP
>    Affects Versions: 1.3.1
>            Reporter: Matteo Ferrario
>         Attachments: heap-dump1.png, heap-dump2.png, heap-dump3.png, Schermata 2017-09-27
alle 00.35.53.png
> The NestedMapsStateTable grows up continuously without free the heap memory.
> We created a simple job that processes a stream of messages and uses CEP to generate
an outcome message when a specific pattern is identified.
> The messages coming from the stream are grouped by a key defined in a specific field
of the message.
> We've also added the "within" clause (set as 5 minutes), indicating that two incoming
messages match the pattern only if they come in a certain time window.
> What we've seen is that for every key present in the message, an NFA object is instantiated
in the NestedMapsStateTable and it is never deallocated.
> Also the "within" clause didn't help: we've seen that if we send messages that don't
match the pattern, the memory grows up (I suppose that the state of NFA is updated) but it
is not cleaned also after the 5 minutes of time window defined in "within" clause.
> If you need, I can provide more details about the job we've implemented and also the
screenshots about the memory leak.

This message was sent by Atlassian JIRA

View raw message