[
https://issues.apache.org/jira/browse/CASSANDRA-4718?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13996074#comment-13996074
]
Jason Brown commented on CASSANDRA-4718:
----------------------------------------
[~enigmacurry] Also, is it possible for you to fill up the disks with more
sstables than available memory? I think we shouyld check how going to disk
plays into the performance mix, rather than just reading from page cache for
the entire read test. This should introduce another modality into the way the
algorithm behaves, one that is probably more realistic to the real world (a mix
of page cache hits and disk seeks).
[~benedict] This rewrite is quite extensive wrt prior branches. As it this code
is quite complex with many new additions, I will need a good chunk of time
tomorrow to review this.
> 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, aws.svg,
> backpressure-stress.out.txt, baq vs trunk.png,
> belliotsmith_branches-stress.out.txt, jason_read.svg, jason_read_latency.svg,
> jason_write.svg, 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.)
--
This message was sent by Atlassian JIRA
(v6.2#6252)
