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https://issues.apache.org/jira/browse/FLINK-10052?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16816118#comment-16816118
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Xiaogang Shi commented on FLINK-10052:
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What's the status of the issue? [~Wosinsan]
{{SessionConnectionStateErrorPolicy}} is introduced in Curator 3.0 while Flink
is using Curator 2.12.
Since Curator 3.x has problems in the compatibility with Zookeeper 3.x,
[Zookeeper Compatibility | [https://curator.apache.org/zk-compatibility.html]]
, we should bump our Curator version to 4.x to use
{{SessionConnectionStateErrorPolicy}}.
What do you think? [~till.rohrmann]
> Tolerate temporarily suspended ZooKeeper connections
> ----------------------------------------------------
>
> Key: FLINK-10052
> URL: https://issues.apache.org/jira/browse/FLINK-10052
> Project: Flink
> Issue Type: Improvement
> Components: Runtime / Coordination
> Affects Versions: 1.4.2, 1.5.2, 1.6.0
> Reporter: Till Rohrmann
> Assignee: Dominik Wosiński
> Priority: Major
>
> This issue results from FLINK-10011 which uncovered a problem with Flink's HA
> recovery and proposed the following solution to harden Flink:
> The {{ZooKeeperLeaderElectionService}} uses the {{LeaderLatch}} Curator
> recipe for leader election. The leader latch revokes leadership in case of a
> suspended ZooKeeper connection. This can be premature in case that the system
> can reconnect to ZooKeeper before its session expires. The effect of the lost
> leadership is that all jobs will be canceled and directly restarted after
> regaining the leadership.
> Instead of directly revoking the leadership upon a SUSPENDED ZooKeeper
> connection, it would be better to wait until the ZooKeeper connection is
> LOST. That way we would allow the system to reconnect and not lose the
> leadership. This could be achievable by using Curator's {{LeaderSelector}}
> instead of the {{LeaderLatch}}.
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