Mailing-List: contact dev-help@jackrabbit.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@jackrabbit.apache.org
Date: Fri, 3 May 2013 21:04:15 +0000 (UTC)
From: "Cody Burleson (JIRA)" <jira@apache.org>
To: dev@jackrabbit.apache.org
Message-ID: <JIRA.12645883.1367534535673.267431.1367615055818@arcas>
In-Reply-To: <JIRA.12645883.1367534535673@arcas>
References: <JIRA.12645883.1367534535673@arcas>
Subject: [jira] [Updated] (JCR-3588) Response time higher on Node1 with load
 when Node2 has no load
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable


     [ https://issues.apache.org/jira/browse/JCR-3588?page=3Dcom.atlassian.=
jira.plugin.system.issuetabpanels:all-tabpanel ]

Cody Burleson updated JCR-3588:
-------------------------------

    Attachment: Screen Shot 2013-05-03 at 3.49.52 PM.png

See the attached image, Screen Shot 2013-05-03. As to be expected, throughp=
ut decreases as the response time increases when we take load off one of th=
e nodes, (leaving the load only on the other node). This happens at positio=
n 44-45 (counter numbers along the bottom of each report graph)
               =20
> Response time higher on Node1 with load when Node2 has no load
> --------------------------------------------------------------
>
>                 Key: JCR-3588
>                 URL: https://issues.apache.org/jira/browse/JCR-3588
>             Project: Jackrabbit Content Repository
>          Issue Type: Bug
>          Components: clustering
>    Affects Versions: 2.4.3
>         Environment: CentOS 6.4 running WebSphere Application Server 7.0.=
0.19. Jackrabbit cluster configuration with 2 WAS servers. Repository on DB=
2 9.7.
>            Reporter: Cody Burleson
>         Attachments: JackrabbitCluster-ResponseTime.png, Node1repository.=
xml, Node2repository.xml, Screen Shot 2013-05-03 at 3.49.52 PM.png
>
>
> In our performance analysis, we are seeing a strange effect, which we doe=
s not make sense to us. It may or may not be a defect, but we need to under=
stand why the effect occurs. In a 2 node cluster, we can run a certain load=
 (reading and writing) directly on Node1 and an equivalent load (reading an=
d writing on Node2). We measure the response time on both nodes, and it's l=
ess than 2 seconds. If we stop the load to one of the servers, the response=
 time on the other server triples (with no additional load). See attached i=
mage "JackrabbitCluster-ResponseTime.png". The left side of the report show=
s when only one node (Node1) has load and Node2 has no load. In this case, =
the response times on Node1 are at about 6 seconds. Then, on the right side=
 of the report, we add an equivalent load to Node2 and then the response ti=
mes on Node1 drop to 2 seconds. So, the load on Node1 was always consistent=
, yet ADDING load to Node2 actually improves response time on Node1. Logica=
lly, it doesn't make much sense, eh? Someone, please, at least help us unde=
rstand why this may be happening.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrato=
rs
For more information on JIRA, see: http://www.atlassian.com/software/jira