[Richfaces-exadel] Fwd: [seam-dev] Some profiling of blockingthreads

[Jay Balunas]

I was able to update and build with RichFaces 3.3.0-SNAPSHOT and saw your
changes.

The good news is that I no longer see any blocking threads in the
"org.ajax4jsf.application.AjaxViewHandler" - none at all which is great.

The bad news is that the performance has not increased in any meaningful or
repeatable way.

During my profiling I noticed a definite increase in the blocked threads
performing JNDI lookups.  My theory is that the AjaxViewHandler was acting
as a gate and effectively slowing down concurrent requests into Seam
proper.  These threads now fly straight through and into Seam processing.
They the end up blocked with the other threads performing the lookups.

I will continue to look at the lookup issues, and let you all know what I
find.

-Jay


On Tue, Sep 30, 2008 at 2:05 PM, Jay Balunas <jbalunas at redhat.com> wrote:

> Excellent  - I will build from sources and test the changes.
>
> I'll post the findings up on seam-dev.
>
> -Jay
> ----- "Nick Belaevski" <nbelaevski at exadel.com> wrote:
>
> > All,
> >
> > I've created JIRA issue for this optimization:
> > https://jira.jboss.org/jira/browse/RF-4554 and have just fixed it.
> >
> > As from now ViewHandlerWrapper#fillChain method is not synchronized
> > anymore.
> >
> > Best regards,
> >   Nick Belaevski
> >
> > > -----Original Message-----
> > > From: richfaces-exadel-bounces at redhat.com [mailto:richfaces-exadel-
> > > bounces at redhat.com] On Behalf Of Max Rydahl Andersen
> > > Sent: Tuesday, September 30, 2008 10:32 AM
> > > To: Jay Balunas; richfaces-exadel at redhat.com
> > > Subject: Re: [Richfaces-exadel] Fwd: [seam-dev] Some profiling of
> > > blockingthreads
> > >
> > > Sergey/Nik ? Any news on this one ?
> > >
> > > /max
> > >
> > > > Hi Guys,
> > > >
> > > > I have been doing some performance testing on seam applications
> > and have
> > > > been able to post some of the results.  One of the areas that I
> > have
> > > > investigated so far was blocking/waiting threads.
> > > >
> > > > In my example I am running 25 concurrent users and hitting the
> > seam wiki
> > > > example.  I am seeing blocked threads waiting on
> > > > "org.ajax4jsf.application.AjaxViewHandler".
> > > > I have investigated it a bit (see below), and have included some
> > of the
> > > > discussions on the seam-dev list.
> > > >
> > > > I would like to get an opinion of the synchronized fillChain
> > method, and
> > > > see
> > > > if there is another way to handle this.
> > > >
> > > > Thoughts?
> > > >
> > > > Thanks,
> > > > Jay
> > > >
> > > > ---------- Forwarded message ----------
> > > > From: Emmanuel Bernard <emmanuel at hibernate.org>
> > > > Date: Thu, Sep 25, 2008 at 10:01 AM
> > > > Subject: Re: [seam-dev] Some profiling of blocking threads
> > > > To: Jay Balunas <tech4j at gmail.com>
> > > > Cc: Pete Muir <pmuir at redhat.com>, "seam-dev at lists.jboss.org" <
> > > > seam-dev at lists.jboss.org>
> > > >
> > > >
> > > >
> > > > On  Sep 25, 2008, at 09:17, Jay Balunas wrote:
> > > >
> > > > org.ajax4jsf.application.AjaxViewHandler
> > > >> --------------------------------------------
> > > >>  - This was not a large % of the blocked threads but caught my
> > eye as a
> > > >> potential trouble spot because it seemed directly related to
> > ajax
> > > calls.
> > > >>  - This was easier to track down and the root cause is in the
> > > >> org.ajax4jsf.application.ViewHandlerWrapper class.
> > > >>  - see
> > > >>
> > >
> >
> http://anonsvn.jboss.org/repos/richfaces/trunk/framework/api/src/main/java
> > > /org/ajax4jsf/application/ViewHandlerWrapper.java
> > > >>  - The problem is all the calls to "fillChain" which is a
> > synchronized
> > > >> method in the class.
> > > >>  - We need to find out how often the "_initialized" field is
> > false - is
> > > >> this once a request, once for each component, etc...
> > > >>  - it appears to be called many times - I will look further into
> > this.
> > > >>
> > > >>
> > > > I will raise this the richfaces dev guys, and see what can be
> > done.
> > > >
> > > >
> > > > Using the double check lock pattern with a volatile should make
> > things
> > > > better. It has to be done right though :)
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > > --
> > > /max
> > >
> > > _______________________________________________
> > > Richfaces-exadel mailing list
> > > Richfaces-exadel at redhat.com
> > > https://www.redhat.com/mailman/listinfo/richfaces-exadel
> >
> > _______________________________________________
> > Richfaces-exadel mailing list
> > Richfaces-exadel at redhat.com
> > https://www.redhat.com/mailman/listinfo/richfaces-exadel
>



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