[
https://issues.apache.org/jira/browse/RATIS-840?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
runzhiwang updated RATIS-840:
-----------------------------
Attachment: (was: RATIS-840.001.patch)
> Memory leak of LogAppender
> --------------------------
>
> Key: RATIS-840
> URL: https://issues.apache.org/jira/browse/RATIS-840
> Project: Ratis
> Issue Type: Bug
> Components: server
> Reporter: runzhiwang
> Assignee: runzhiwang
> Priority: Major
> Attachments: image-2020-04-06-14-27-28-485.png,
> image-2020-04-06-14-27-39-582.png, screenshot-1.png
>
>
> *What's the problem ?*
> When run hadoop-ozone for 4 days, datanode memory leak. When dump heap, I
> found there are 460710 instances of GrpcLogAppender. But there are only 6
> instances of SenderList, and each SenderList contains 1-2 instance of
> GrpcLogAppender. And there are a lot of logs related to
> [LeaderState::restartSender|https://github.com/apache/incubator-ratis/blob/master/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderState.java#L428].
> {code:java}INFO impl.RaftServerImpl:
> 1665f5ea-ab17-4a0e-af6d-6958efd322fa@group-F64B465F37B5-LeaderState:
> Restarting GrpcLogAppender for
> 1665f5ea-ab17-4a0e-af6d-6958efd322fa@group-F64B465F37B5-\u003e229cbcc1-a3b2-4383-9c0d-c0f4c28c3d4a\n","stream":"stderr","time":"2020-04-06T03:59:53.37892512Z"}{code}
>
> So there are a lot of GrpcLogAppender did not stop the Daemon Thread when
> removed from senders.
> !image-2020-04-06-14-27-28-485.png!
> !image-2020-04-06-14-27-39-582.png!
>
> *Why
> [LeaderState::restartSender|https://github.com/apache/incubator-ratis/blob/master/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderState.java#L428]
> so many times ?*
> 1. As the image shows, when remove group, SegmentedRaftLog will close, then
> GrpcLogAppender throw exception when find the SegmentedRaftLog was closed.
> Then GrpcLogAppender will be
> [restarted|https://github.com/apache/incubator-ratis/blob/master/ratis-server/src/main/java/org/apache/ratis/server/impl/LogAppender.java#L94],
> and the new GrpcLogAppender throw exception again when find the
> SegmentedRaftLog was closed, then GrpcLogAppender will be restarted again ...
> . It results in an infinite restart of GrpcLogAppender.
> !screenshot-1.png!
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
