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https://issues.apache.org/jira/browse/MESOS-1038?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13912241#comment-13912241
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Jie Yu commented on MESOS-1038:
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https://reviews.apache.org/r/18488/
> Log coordinator should demote itself after a write is discarded.
> ----------------------------------------------------------------
>
> Key: MESOS-1038
> URL: https://issues.apache.org/jira/browse/MESOS-1038
> Project: Mesos
> Issue Type: Bug
> Affects Versions: 0.17.0
> Reporter: Jie Yu
> Assignee: Jie Yu
> Fix For: 0.18.0
>
>
> After a write operation (append/truncate) is discarded (e.g. due to timeout),
> the log coordinator should demoted itself, because it does not know if the
> previous write operation has been agreed or not. It needs to get re-elected
> to be able to write again.
> Consider the following case: there are 3 replicas R1, R2 and R3, and C1 is
> the coordinator co-located with R1. Say C1 tries to write at position 1. All
> replicas receive the write request and accept the write request. C1
> successfully collects a quorum of OK responses, and right before it sends out
> the learned message, the write operation is discarded.
> The value at position 1 has been agreed, however, if we don't demote C1 after
> the write operation is discarded, C1 will try to write to the same position
> (position 1) again, with possibly a different value. And that value can be
> later agreed by all replicas, leading to an inconsistency.
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