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https://issues.apache.org/jira/browse/HBASE-7268?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13530540#comment-13530540
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Sergey Shelukhin commented on HBASE-7268:
-----------------------------------------
Yes, as long as the clock on the master doesn't act funny. From my experience
clocks cannot be trusted... maybe if we had reliable sequence mechanism of some
kind.
In the original run, it happened due to multiple threads - one thread errors
out on A with "moved to B", errors out on B, goes to META, and updates cache
w/C; meanwhile, some other thread just errorred out on A with "moved to B", so
he goes and rewrites C with B again.
> correct local region location cache information can be overwritten w/stale
> information from an old server
> ---------------------------------------------------------------------------------------------------------
>
> Key: HBASE-7268
> URL: https://issues.apache.org/jira/browse/HBASE-7268
> Project: HBase
> Issue Type: Bug
> Affects Versions: 0.96.0
> Reporter: Sergey Shelukhin
> Assignee: Sergey Shelukhin
> Priority: Minor
> Fix For: 0.96.0
>
> Attachments: HBASE-7268-v0.patch, HBASE-7268-v0.patch,
> HBASE-7268-v1.patch, HBASE-7268-v2.patch
>
>
> Discovered via HBASE-7250; related to HBASE-5877.
> Test is writing from multiple threads.
> Server A has region R; client knows that.
> R gets moved from A to server B.
> B gets killed.
> R gets moved by master to server C.
> ~15 seconds later, client tries to write to it (on A?).
> Multiple client threads report from RegionMoved exception processing logic "R
> moved from C to B", even though such transition never happened (neither in
> nor before the sequence described below). Not quite sure how the client
> learned of the transition to C, I assume it's from meta from some other
> thread...
> Then, put fails (it may fail due to accumulated errors that are not logged,
> which I am investigating... but the bogus cache update is there
> nonwithstanding).
> I have a patch but not sure if it works, test still fails locally for yet
> unknown reason.
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