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https://issues.apache.org/jira/browse/CASSANDRA-4718?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13986039#comment-13986039
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Benedict commented on CASSANDRA-4718:
-------------------------------------
bq. Perhaps, but the overall improvement in performance (should we attribute
that to the work stealing?) seems compelling enough.
I'm not suggesting we forego the patch because of this concern, I'm raising it
as something to bear in mind for the future. As I said, though, to some extent
I have addressed this concern with the _lowsignal_ patch I uploaded, although
it's debatable how elegant that approach is.
bq. I didn't consider this a 'fork' as we're not mucking about with the
internals of the FJP itself.
Perhaps we're getting crossed wires and mixing up the patches I have uploaded
(no fork), with the suggestion that we _may want to investigate forking in
future_ in order to address these issues in a more elegant manner.
> More-efficient ExecutorService for improved throughput
> ------------------------------------------------------
>
> Key: CASSANDRA-4718
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4718
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Jonathan Ellis
> Assignee: Jason Brown
> Priority: Minor
> Labels: performance
> Fix For: 2.1.0
>
> Attachments: 4718-v1.patch, PerThreadQueue.java, baq vs trunk.png, op
> costs of various queues.ods, stress op rate with various queues.ods,
> v1-stress.out
>
>
> Currently all our execution stages dequeue tasks one at a time. This can
> result in contention between producers and consumers (although we do our best
> to minimize this by using LinkedBlockingQueue).
> One approach to mitigating this would be to make consumer threads do more
> work in "bulk" instead of just one task per dequeue. (Producer threads tend
> to be single-task oriented by nature, so I don't see an equivalent
> opportunity there.)
> BlockingQueue has a drainTo(collection, int) method that would be perfect for
> this. However, no ExecutorService in the jdk supports using drainTo, nor
> could I google one.
> What I would like to do here is create just such a beast and wire it into (at
> least) the write and read stages. (Other possible candidates for such an
> optimization, such as the CommitLog and OutboundTCPConnection, are not
> ExecutorService-based and will need to be one-offs.)
> AbstractExecutorService may be useful. The implementations of
> ICommitLogExecutorService may also be useful. (Despite the name these are not
> actual ExecutorServices, although they share the most important properties of
> one.)
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