You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@qpid.apache.org by "ASF subversion and git services (JIRA)" <ji...@apache.org> on 2014/07/22 14:36:38 UTC
[jira] [Commented] (QPID-5910) Throughput regression relative to
0.14
[ https://issues.apache.org/jira/browse/QPID-5910?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14070204#comment-14070204 ]
ASF subversion and git services commented on QPID-5910:
-------------------------------------------------------
Commit 1612559 from [~mgoulish] in branch 'qpid/trunk'
[ https://svn.apache.org/r1612559 ]
QPID-5910
The previous way of computing required credit was apparently
pretty slow -- perhaps because it is doing some unnceessary
copying down in its guts. (Which theory I did not prove.)
And it was running while a lock was held, which caused a
significant throughput regression (which was reported as an
enormous latency regression.)
The simpler means of calculating credit in this diff removes
most of the problem.
> Throughput regression relative to 0.14
> --------------------------------------
>
> Key: QPID-5910
> URL: https://issues.apache.org/jira/browse/QPID-5910
> Project: Qpid
> Issue Type: Bug
> Affects Versions: 0.22
> Reporter: michael goulish
> Assignee: michael goulish
> Fix For: 0.29
>
>
> If you use qpid-latency-test, hold message size constant, and gradually increase the sending rate (in several tests) you will sooner or later reach a point at which the messaging system's ability to handle throughput saturates. When that happens, latency will go sky-high. (I have producer flow-control turned off to be able to compare vs. older code.)
> The latest code reaches throughput saturation significantly earlier than older code. (i.e. at a lower sending rate.)
> Also, using 'perf' to help analyze the code, recent code is executing significantly fewer instructions per second than older code.
> This probably indicates that come parts of the code are spending too much time *while a lock is held* -- thus preventing other threads from fulfilling their destiny, and having an effect on overall throughput.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@qpid.apache.org
For additional commands, e-mail: dev-help@qpid.apache.org