[
https://issues.apache.org/jira/browse/SOLR-12833?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16824104#comment-16824104
]
Andrzej Bialecki commented on SOLR-12833:
------------------------------------------
Looking closer at the code I don't think it can be easily refactored to use two
implementations of VersionBucket (I'd love to be proven wrong, though!) - since
the only way to use the intrinsic object monitor is by using {{synchronized}}
keyword around a block the usage would become very complicated, basically we
would have to factor out two almost identical methods for each of the sections
where bucket locking is used.
So I guess for now the solution for that use case is to drastically reduce the
number of buckets.
> Use timed-out lock in DistributedUpdateProcessor
> ------------------------------------------------
>
> Key: SOLR-12833
> URL: https://issues.apache.org/jira/browse/SOLR-12833
> Project: Solr
> Issue Type: Improvement
> Security Level: Public(Default Security Level. Issues are Public)
> Components: update, UpdateRequestProcessors
> Affects Versions: 7.5, 8.0
> Reporter: jefferyyuan
> Assignee: Mark Miller
> Priority: Minor
> Fix For: 7.7, 8.0
>
> Attachments: SOLR-12833-noint.patch, SOLR-12833.patch,
> SOLR-12833.patch
>
> Time Spent: 20m
> Remaining Estimate: 0h
>
> There is a synchronize block that blocks other update requests whose IDs fall
> in the same hash bucket. The update waits forever until it gets the lock at
> the synchronize block, this can be a problem in some cases.
>
> Some add/update requests (for example updates with spatial/shape analysis)
> like may take time (30+ seconds or even more), this would the request time
> out and fail.
> Client may retry the same requests multiple times or several minutes, this
> would make things worse.
> The server side receives all the update requests but all except one can do
> nothing, have to wait there. This wastes precious memory and cpu resource.
> We have seen the case 2000+ threads are blocking at the synchronize lock, and
> only a few updates are making progress. Each thread takes 3+ mb memory which
> causes OOM.
> Also if the update can't get the lock in expected time range, its better to
> fail fast.
>
> We can have one configuration in solrconfig.xml:
> updateHandler/versionLock/timeInMill, so users can specify how long they want
> to wait the version bucket lock.
> The default value can be -1, so it behaves same - wait forever until it gets
> the lock.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org
For additional commands, e-mail: dev-h...@lucene.apache.org
