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runzhiwang updated RATIS-840: ----------------------------- Attachment: screenshot-1.png > 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: RATIS-840.001.patch, 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 ?* > *What's the reason ?* > From the code, when > [removeSender|https://github.com/apache/incubator-ratis/blob/master/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderState.java#L431] > in > [LeaderState::restartSender|https://github.com/apache/incubator-ratis/blob/master/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderState.java#L428], > it did not call > [LogAppender::stopAppender|https://github.com/apache/incubator-ratis/blob/master/ratis-server/src/main/java/org/apache/ratis/server/impl/LogAppender.java#L164]. > > *How to fix ?* > To avoid forgetting stopAppender, I stopAppender in [SenderList > ::removeAll|https://github.com/apache/incubator-ratis/blob/master/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderState.java#L173]. > -- This message was sent by Atlassian Jira (v8.3.4#803005)