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Date: Sat, 10 May 2014 22:14:40 +0000 (UTC)
From: "Ryan McGuire (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
Message-ID: <JIRA.12609097.1348596683790.323413.1399760080928@arcas>
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Subject: [jira] [Commented] (CASSANDRA-4718) More-efficient ExecutorService
 for improved throughput
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    [ https://issues.apache.org/jira/browse/CASSANDRA-4718?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13993374#comment-13993374 ] 

Ryan McGuire commented on CASSANDRA-4718:
-----------------------------------------

Above is with 4 nodes, one of which was the one hosting stress. Here's a 3 node variety, with stress on a separate host:

 * [30 threads|http://riptano.github.io/cassandra_performance/graph_v3/graph.html?stats=stats.4718.3node.threads-30.log]
 * [90 threads|http://riptano.github.io/cassandra_performance/graph_v3/graph.html?stats=stats.4718.3node.threads-90.log]
 * [270 threads|http://riptano.github.io/cassandra_performance/graph_v3/graph.html?stats=stats.4718.3node.threads-270.log]
 * [810 threads|http://riptano.github.io/cassandra_performance/graph_v3/graph.html?stats=stats.4718.3node.threads-810.log]
  

> 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.)


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