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https://issues.apache.org/jira/browse/HBASE-7735?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13607173#comment-13607173
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terry zhang commented on HBASE-7735:
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Hi Jonathan Hsieh， Can we use below methods to increase the probability of
snapshots succeeding?
1. get all the region list in master. Including moving region , online region
and spliting region(parent and child)
2. check the region list to make sure there is no hole in it.
3. generate a snapshot task assign map file in the target snapshot folder.
(also assign the moving regions and spliting parent regions to some region
server )
4. when the regionserver start buildSubprocedure. it will compare online region
and the assgin region list in task file which master generated . if it is a
online region it will be a FlushSnapshotSubprocedure. if it is not online we
can think it is a close region. we do not need to flush cache , only need to
create reference file(empty file). If the region already in the snapshot
folder. we can just skip .
I think this would be helpful cause in large cluster moving region and spliting
region is a normal stituation. So snapshot maybe always fail when do the
verification. what do you think ?
> Prevent regions from moving during online snapshot.
> ---------------------------------------------------
>
> Key: HBASE-7735
> URL: https://issues.apache.org/jira/browse/HBASE-7735
> Project: HBase
> Issue Type: Sub-task
> Reporter: Jonathan Hsieh
>
> To increase the probability of snapshots succeeding, we should attempt to
> prevent splits and region moves from happening. Currently we take region
> locks but this could be "too late" and results in an aborted snapshot.
> We should probably take the table lock (0.96) when starting a snapshot and
> for a 0.94 backport we should probably disable the balancer.
> This will probably not be tackled until after trunk merge.
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