I take my words back about the workaround.
It's much more complicated.
On Tue, 2010-06-01 at 09:23 +0300, Deyan Tsvetanov wrote:
> Hi guys,
>
> removing synchronized from begin( int timeout) will cause issues.
> The problematic code is the following:
> (starting from line 180 in TransactionUtil.java - trunk )
>
> // reset the transaction stamps, just in case...
>
> clearTransactionStamps();
> // initialize the start stamp
> getTransactionStartStamp();
> // set the tx begin stack placeholder
> setTransactionBeginStack();
>
> So the synchronized begin() is a huge bottleneck and imho it can't be
> solved without coding. Caching is not a solution.
> I think the transaction timestamps and the transaction begin stack have
> to be moved to the UserTransaction so they are not static anymore.
> In general TransactionUtil needs some rework.
>
> Cheers,
> Deyan
>
> On Mon, 2010-05-31 at 14:34 -0600, David E Jones wrote:
> > The theory that Martin mentioned is interesting, and quite possible. Have
> > you tried removing the synchronized keyword from the begin method to see if
> > it helps?
> >
> > That would just be to test the theory, and if that does turn out to be the
> > bottleneck then the sensitive parts of the method should be synchronized
> > (or put into separate synchronized methods) instead of snycing the whole
> > method.
> >
> > -David
> >
> >
> > On May 31, 2010, at 2:24 PM, Karl Pitrich wrote:
> >
> > > Hi,
> > >
> > > I'm working with Martin on this project.
> > >
> > > We have commented the various cache options as described in the Wiki (and
> > > mailing list),
> > > EXPIRE TIME is 0 in all except for product.* when viewing
> > > /webtools/control/FindUtilCache
> > >
> > > Logging is disabled, as are several components.
> > > Also, we have disabled several content elements from the template, such
> > > as recommendations or polls, etc.
> > >
> > >
> > > Any help is appreciated,
> > > Greetings,
> > >
> > > - Karl
> > >
> > > On 31.05.2010, at 22:07, Jacques Le Roux wrote:
> > >
> > >> 1st level of answer, did you set caches?
> > >> https://cwiki.apache.org/confluence/display/OFBTECH/Apache+OFBiz+Technical+Production+Setup+Guide#ApacheOFBizTechnicalProductionSetupGuide-CacheSettings
> > >> https://cwiki.apache.org/confluence/display/OFBADMIN/Scaling+and+Performance+Plan
> > >>
> > >> Jacques
> > >>
> > >> From: "Martin Kreidenweis" <martin.kreidenw...@tngtech.com>
> > >>> Hi,
> > >>>
> > >>> we are currently evaluating Apache OFBiz for use in one of our projects.
> > >>>
> > >>> We expect a high load on our application. So we did a test with jMeter
> > >>> on the sample ecommerce application with 100 parallel sessions and in
> > >>> average 400 msec (randomized) wait time between requests.
> > >>>
> > >>> During profiling we experienced that
> > >>> org.ofbiz.entity.transaction.TransactionUtil.begin() is by far the
> > >>> dominating method invoked and the application spends about 75% of total
> > >>> time in this method.
> > >>> This results in page load times over 10 seconds and growing.
> > >>>
> > >>> Many threads are blocked because the method is defined as static and
> > >>> synchronized.
> > >>>
> > >>> We are using MySQL as a database backend in our test setup and
> > >>> deactivated all informational logging (even server hit statistics), and
> > >>> most of the sidebar widgets.
> > >>>
> > >>> Any suggestions/ideas are highly appreciated.
> > >>> Thanks.
> > >>>
> > >>> Best regards,
> > >>> Martin
> >
>
>
