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https://issues.apache.org/jira/browse/HBASE-9110?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13751887#comment-13751887
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Himanshu Vashishtha commented on HBASE-9110:
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Yes, you would have the same problem. Separate meta wal feature (though very
useful for MTTR) introduces a tight dependency on zk data I'd say. If we delete
zk data (meta server znode), then we no longer split meta logs before assigning.
Do you have some use case to delete zk data (apart from 0.96 upgrade)?
If so, I think we can leverage the above patch: create the upgradeInprogress
znode so that master splits all the logs before opening regions.
> Meta region edits not recovered while migrating to 0.96.0
> ---------------------------------------------------------
>
> Key: HBASE-9110
> URL: https://issues.apache.org/jira/browse/HBASE-9110
> Project: HBase
> Issue Type: Sub-task
> Components: migration
> Affects Versions: 0.95.2, 0.94.10
> Reporter: Himanshu Vashishtha
> Priority: Critical
> Fix For: 0.96.0
>
> Attachments: HBase-9110-v0.patch
>
>
> I was doing the migration testing from 0.94.11-snapshot to 0.95.0, and faced
> this issue.
> 1) Do some edits in meta table (for eg, create a table).
> 2) Kill the cluster.
> (I used kill because we would be doing log splitting when upgrading anyway).
> 3) There is some dependency on WALs. Upgrade the bits to 0.95.2-snapshot.
> Start the cluster.
> Every thing comes up. I see log splitting happening as expected. But, the
> WAL-data for meta table is missing.
> I could see recovered.edits file for meta created, and placed at the right
> location. It is just that the new HMaster code tries to recover meta by
> looking at meta prefix in the log name, and if it didn't find one, just opens
> the meta region. So, the recovered.edits file, created afterwards, is not
> honored.
> Opening this jira to let folks give their opinions about how to tackle this
> migration issue.
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