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https://issues.apache.org/jira/browse/ZOOKEEPER-475?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12732451#action_12732451
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Flavio Paiva Junqueira commented on ZOOKEEPER-475:
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Great catch! (I know it was hudson, but it was good that you've seen it)
The short version of the story is that the synchronization is not correct in
QuorumCnxManager.
The longer version is like this. From the traces, I can see the following
sequence of messages:
* Replica 1 sends a message to itself and to Replica 2 stating that its current
vote is for replica 1;
* Replica 2 sends a message to itself and to Replica 1 stating that its current
vote is for replica 2;
* Replica 1 updates its vote, and sends a message to itself stating that its
current vote is for replica 2;
* Since replica 1 has two votes for 2 in a an ensemble of 3 replicas, replica 1
decides to follow 2.
The problem is that replica 2 does not receive a message from 1 stating that it
changed its vote to 2, which prevents 2 from becoming a leader. Now looking
more carefully at why that happened, you can see that when 1 tries to send a
message to 2, QuorumCnxManager in 1 is both shutting down a connection to 2 at
the same time that it is trying to open a new one. The incorrect
synchronization prevents the creation of a new connection, and 1 and 2 end up
not connected.
> FLENewEpochTest failed on nightly builds.
> -----------------------------------------
>
> Key: ZOOKEEPER-475
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-475
> Project: Zookeeper
> Issue Type: Bug
> Reporter: Mahadev konar
> Assignee: Flavio Paiva Junqueira
> Fix For: 3.2.1, 3.3.0
>
>
> THe flenewepochtest failed on one of the nightly builds -
> http://hudson.zones.apache.org/hudson/view/ZooKeeper/job/ZooKeeper-trunk/377.
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