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https://issues.apache.org/jira/browse/ZOOKEEPER-3479?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Michael Han reassigned ZOOKEEPER-3479:
--------------------------------------
Assignee: Karolos Antoniadis
> Logging false leader election times
> -----------------------------------
>
> Key: ZOOKEEPER-3479
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3479
> Project: ZooKeeper
> Issue Type: Bug
> Components: leaderElection
> Affects Versions: 3.5.5
> Reporter: Karolos Antoniadis
> Assignee: Karolos Antoniadis
> Priority: Minor
> Labels: pull-request-available
> Attachments: server1.txt, server2.txt
>
> Time Spent: 2h 20m
> Remaining Estimate: 0h
>
> There seems to be a problem with the logging of leader election times: the
> logged times are much smaller than the actual time it took for the leader
> election to complete.
> This bug can be easily reproduced by following these steps:
> 1) Run a ZK cluster of 3 servers
> 2) Kill the server that is currently the leader
> 3) The log files of the remaining 2 servers contain false leader election
> times
>
> In the attached files you can see the log files of the remaining 2 serve. For
> brevity, I removed the parts before and after the leader election from the
> log files.
> For example, in {{server1.txt}} we can see that:
>
> {code:java}
> 2019-07-31 00:57:31,852 [myid:1] - WARN
> [QuorumPeer[myid=1](plain=/0.0.0.0:2791)(secure=disabled):QuorumPeer@1318] -
> PeerState set to LOOKING
> 2019-07-31 00:57:31,853 [myid:1] - INFO
> [QuorumPeer[myid=1](plain=/0.0.0.0:2791)(secure=disabled):QuorumPeer@1193] -
> LOOKING
> 2019-07-31 00:57:31,853 [myid:1] - INFO
> [QuorumPeer[myid=1](plain=/0.0.0.0:2791)(secure=disabled):FastLeaderElection@885]
> - New election. My id = 1, proposed zxid=0x100000001
> [...]
> 2019-07-31 00:57:32,272 [myid:1] - INFO
> [QuorumPeer[myid=1](plain=/0.0.0.0:2791)(secure=disabled):Follower@69] -
> FOLLOWING - LEADER ELECTION TOOK - 1 MS{code}
> Leader election supposedly took only 1ms, but in reality it took (32,272 -
> 31,853) = 419ms!
> The reason for this bug seems to be the introduction of this line
> {code:java}
> start_fle = Time.currentElapsedTime();{code}
> (seen here
> [https://github.com/apache/zookeeper/blob/master/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/QuorumPeer.java#L1402])
>
> back in this commit
> [https://github.com/apache/zookeeper/commit/5428cd4bc963c2e653a260c458a8a8edf3fa08ef].
>
>
>
>
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