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https://issues.apache.org/jira/browse/JCR-3738?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jukka Zitting updated JCR-3738:
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Assignee: (was: Jukka Zitting)
So far I couldn't find any clear reasons for why this would happen.
One possible lead is that this might have something to do with the way
ConnectionHelper uses the TransactionContext.getCurrentThreadId() to share a
connection across threads when they're linked into the same transaction.
There's a workaround in configuring the database backend to timeout blocked
statements. It breaks this deadlock, so a partial solution (that doesn't fix
the root cause) might be to try using Statement.setQueryTimeout() in
DatabaseJournal.doLock().
> CLONE - Deadlock on LOCAL_REVISION table in clustering environment
> ------------------------------------------------------------------
>
> Key: JCR-3738
> URL: https://issues.apache.org/jira/browse/JCR-3738
> Project: Jackrabbit Content Repository
> Issue Type: Bug
> Components: clustering
> Affects Versions: 2.6.2
> Environment: CQ5.6.1 with jackrabbit-core 2.6.2 backed off ibm db2
> v10.5
> Reporter: Ankush Malhotra
> Priority: Critical
> Attachments: before-lock.zip, db-deadlock-info.txt, stat-cache.log,
> threaddumps.zip
>
>
> Original, cloned description:
> > When inserting a lot of nodes concurrently (100/200 threads) the system
> > hangs generating a deadlock on the LOCAL_REVISION table.
> > There is a thread that starts a transaction but the transaction remains
> > open, while another thread tries to acquire the lock on the table.
> > This actually happen even if there is only a server up but configured in
> > cluster mode.
> > I found that in AbstractJournal, we try to write the LOCAL_REVISION even if
> > we don't sync any record because they're generated by the same journal of
> > the thread running.
> >
> > Removing this unnecessary (to me :-) ) write to the LOCAL_REVISION table,
> > remove the deadlock.
> This might not be the exact same case with this issue. See the attached
> thread dumps etc. for full details.
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