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https://issues.apache.org/jira/browse/CASSANDRA-9143?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15435649#comment-15435649
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Blake Eggleston commented on CASSANDRA-9143:
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Since sstables compacted since the beginning of a repair are excluded from
anticompaction, normal compaction is enough to create large inconsistencies of
the data each node considers repaired. This will cause repaired data to be
considered unrepaired, which will cause a lot of unnecessary streaming on the
next repair.
At a high level, the least complicated solution I’ve come up with is:
Add a ‘pending repair’ bucket to the existing repaired and unrepaired sstable
buckets. We do the anticompaction up front, but put the anticompacted data into
the pending bucket. From here, the repair proceeds normally against the pending
sstables, with the streamed sstables also going into the pending buckets. Once
all nodes have completed streaming, the pending sstables are moved into the
repaired bucket, or back into unrepaired if there’s a failure.
This should keep each replica’s notion of what’s repaired identical, and
minimize over streaming caused by large chunks of repaired data being
classified as unrepaired.
> Improving consistency of repairAt field across replicas
> --------------------------------------------------------
>
> Key: CASSANDRA-9143
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9143
> Project: Cassandra
> Issue Type: Improvement
> Reporter: sankalp kohli
> Priority: Minor
>
> We currently send an anticompaction request to all replicas. During this, a
> node will split stables and mark the appropriate ones repaired.
> The problem is that this could fail on some replicas due to many reasons
> leading to problems in the next repair.
> This is what I am suggesting to improve it.
> 1) Send anticompaction request to all replicas. This can be done at session
> level.
> 2) During anticompaction, stables are split but not marked repaired.
> 3) When we get positive ack from all replicas, coordinator will send another
> message called markRepaired.
> 4) On getting this message, replicas will mark the appropriate stables as
> repaired.
> This will reduce the window of failure. We can also think of "hinting"
> markRepaired message if required.
> Also the stables which are streaming can be marked as repaired like it is
> done now.
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