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https://issues.apache.org/jira/browse/HBASE-5926?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13277172#comment-13277172
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nkeywal commented on HBASE-5926:
--------------------------------
the race condition is decreased to a production-acceptable minimum imho. We do
a compare & delete in the java code, so the race condition is now: between the
comparison and the delete, we fail if, and only if: the session expires and the
master node is deleted and the master backup recreates the node. That's
unlikely.
> Delete the master znode after a master crash
> --------------------------------------------
>
> Key: HBASE-5926
> URL: https://issues.apache.org/jira/browse/HBASE-5926
> Project: HBase
> Issue Type: Improvement
> Components: master, scripts
> Affects Versions: 0.96.0
> Reporter: nkeywal
> Assignee: nkeywal
> Priority: Minor
> Fix For: 0.96.0
>
> Attachments: 5926.v6.patch
>
>
> This is the continuation of the work done in HBASE-5844.
> But we can't apply exactly the same strategy: for the region server, there is
> a znode per region server, while for the master & backup master there is a
> single znode for both.
> So if we apply the same strategy as for a regionserver, we may have this
> scenario:
> 1) Master starts
> 2) Backup master starts
> 3) Master dies
> 4) ZK detects it
> 5) Backup master receives the update from ZK
> 6) Backup master creates the new master node and become the main master
> 7) Previous master script continues
> 8) Previous master script deletes the master node in ZK
> 9) => issue: we deleted the node just created by the new master
> This should not happen often (usually the znode will be deleted soon enough),
> but it can happen.
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