Yes when run under load (25 users) the system seems to becomes
unresponsive. The requests do eventually return - jmeter was reporting an
average request time of 100+ seconds. When accessed during the warm up
requests (my manual requests to prime the application) the application
functioned just fine.
-Jay
On Wed, Nov 12, 2008 at 8:20 PM, Shane Bryzak <shane.bryzak(a)jboss.com>wrote:
Thanks Jay,
Just to be clear, did you mean that each individual request is now taking
100+ seconds as compared to 3 seconds previously?
Jay Balunas wrote:
> Performance Review of current Seam trunk fo 2.1.1
> --------------------------------------------------------
>
> Working with the latest trunk from today (r9557) and testing the
> performance changes that were made. Previous tests were done with (r9017).
> Just as a refresher my baseline test uses the wiki example with all of the
>
sfwk.org <
http://sfwk.org> data up to July 31st 2008.
> For these tests I use JBoss AS 4.2.3 with JDK5 on my linux machine.
> Jmeter is used to load test and calculate the results and graphs. I then
> use JProfiler to to identify either blocking threads, call graphs, and CPU
> usage.
> Unfortunately the results were not good. I was using a mixture of 25 and
> 50 users - hitting the server 25 times each. As before they were accessing
> the first page of the user forum.
>
> With r9017 the 25 user x 25 requests averaged 3 seconds a request. With
> trunk they were 100+ seconds. Thinking something was wrong with the system
> I replaced the 9557 wiki.war with the 9017 and reran with all other
> variables the same. Again the 9017 saw about 3 seconds for the average over
> the 625 requests.
>
> I then profiled the server under load as I did before. The methods below
> appear to be the primary offenders although as with most blocking threads
> there are some others waiting on the same monitor. I'll follow up this
> email with the stack traces, and more information from my investigation.
>
> -----------------------------------
> 1) com.arjuna.ats.jbossatx.jta.TransactionManagerDelegate.findLock(..)
> - This appears to be the biggest issue. Every requests are generating
> many of these calls.
> -
>
http://viewvc.jboss.org/cgi-bin/viewvc.cgi/labs/labs/jbosstm/branches/JBO...
> - It looks like every interaction with any transaction causing
> synchronization issues with this call.
> - We'll need to find a way to limit these calls.
> - I'm guessing some of the changes made for JBSEAM-3519 may be the cause
> although I have not had time to look deeper.
> - See :
>
http://fisheye.jboss.org/browse/Seam/trunk/src/main/org/jboss/seam/transa...
>
http://fisheye.jboss.org/browse/Seam/trunk/src/main/org/jboss/seam/transa...
> >
>
>
http://fisheye.jboss.org/browse/Seam/trunk/src/main/org/jboss/seam/util/W...
>
http://fisheye.jboss.org/browse/Seam/trunk/src/main/org/jboss/seam/util/W...
> >
> -----------------------------------
> 2) org.jboss.naming.ENCFactory.getObjectInstance()
> javax.naming.Context.lookup(java.lang.String)
>
> This appears to be the second biggest offender and it looks like we are
> no longer blocking on retrieving the InitialContext, but now blocking on
> performing the lookups using the context.
> -----------------------------------
> 3)
> org.jboss.resource.connectionmanager.CachedConnectionManager.unregisterConnection()
>
> org.jboss.resource.connectionmanager.CachedConnectionManager.registerConnection()
>
> This is the third biggest issue, but much less than the others. 1 or 2
> dozen blocks on 60 requests. These are all related to hibernate calls and
> database access from what I've seen so far.
> -----------------------------------
> I'll follow up this email tomorrow with the typical stack traces seen for
> each of these.
>
> Shane could you review, and I'll get more information on these tomorrow.
> Thanks,
> -Jay
>
> --
> blog:
http://in.relation.to/Bloggers/Jay
> ------------------------------------------------------------------------
>
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