That's an interesting result. Why, oh why, did I ever implement render variables?
So the conventional thinking on synchronized methods is that they where there is limited contention, and the method is short, synchronized is the best way to go. This method exists, and is synchronized, to avoid creating a PerThreadValue to store the render variable's Map on every component and mixin in the application. That adds up, given that only a tiny percentage of pages or components will ever use a render variable. I'd be willing to replace this code with something that uses an explicit per-instance Lock ... that would likely help with your high contention issues, as after the PerThreadValue is created, and the write lock is released, there would no longer be contention, as all threads could share the read lock. I can put that together shortly and crank out a 5.3.4-rc-1 snapshot, if you can then pick it up and test it. Further comments here: https://issues.apache.org/jira/browse/TAP5-1929 On Fri, May 11, 2012 at 6:07 AM, Robert Lentz <rob...@teksolv.de> wrote: > Hi All, > > we want to rollout a Tapestry app very shortly, but we struggle with > load testing issues. We are currently load testing on one Tomcat 6.0.32: > - 500 worker threads, tapestry.production-mode=true > - Intel(R) Xeon(R) CPU X7460 @ 2.66GHz > - OpenJDK Runtime Environment (IcedTea6 1.7.10) > (rhel-1.20.b17.el5-x86_64) OpenJDK 64-Bit Server VM (build 14.0-b16, > mixed mode)) > and 2 loadrunner test clients. > > After ramping up the concurrent requests (about 5min) we reach the > maximum at about 450req/sec and get server busy errors. We see a high > thread contention on InternalComponentResourcesImpl.postRenderCleanup > currently with the Loop component, as there 10 Loop on the Index page. > Is there a workaround possible without removing the Loop component from > the page to increase the throughput? The thread dumps series looks like > this: 1 thread locks 0x00000000e3858990 and over 400 threads are > waiting. This lock is persistent over a thread dumps series. I guess the > private synchronized Map<String, Object> getRenderVariables(boolean > create) call hits us. > > "http-9080-188" daemon prio=10 tid=0x000000004d463000 nid=0x382a > runnable [0x0000000055b2f000] > java.lang.Thread.State: RUNNABLE > at > org.apache.tapestry5.internal.transform.ParameterWorker$3$1.getState(ParameterWorker.java:206) > at > org.apache.tapestry5.internal.transform.ParameterWorker$3$1.reset(ParameterWorker.java:302) > at > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl$1.work(InternalComponentResourcesImpl.java:136) > at > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl$1.work(InternalComponentResourcesImpl.java:133) > at > org.apache.tapestry5.internal.util.NamedSet.eachValue(NamedSet.java:171) > - locked <0x00000000e3858990> (a > org.apache.tapestry5.internal.util.NamedSet) > at > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl.resetParameterConduits(InternalComponentResourcesImpl.java:546) > - locked <0x00000000e385c038> (a > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl) > at > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl.postRenderCleanup(InternalComponentResourcesImpl.java:522) > at > org.apache.tapestry5.corelib.components.Loop.postRenderCleanup(Loop.java) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl$1.run(ComponentPageElementImpl.java:85) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl.invoke(ComponentPageElementImpl.java:956) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl.access$1800(ComponentPageElementImpl.java:61) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl$PostRenderCleanupPhase.render(ComponentPageElementImpl.java:443) > at > org.apache.tapestry5.internal.services.RenderQueueImpl.run(RenderQueueImpl.java:72) > at > org.apache.tapestry5.internal.services.PageRenderQueueImpl.render(PageRenderQueueImpl.java:124) > at $PageRenderQueue_135675e1f6b934.render(Unknown Source) > at $PageRenderQueue_135675e1f6b933.render(Unknown Source) > at > org.apache.tapestry5.internal.services.MarkupRendererTerminator.renderMarkup(MarkupRendererTerminator.java:37) > ... > "http-9080-499" daemon prio=10 tid=0x000000004dffb000 nid=0x3b7d waiting > for monitor entry [0x0000000069063000] > java.lang.Thread.State: BLOCKED (on object monitor) > at > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl.getRenderVariables(InternalComponentResourcesImpl.java:476) > - waiting to lock <0x00000000e385c038> (a > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl) > at > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl.postRenderCleanup(InternalComponentResourcesImpl.java:517) > at > org.apache.tapestry5.corelib.components.Loop.postRenderCleanup(Loop.java) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl$1.run(ComponentPageElementImpl.java:85) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl.invoke(ComponentPageElementImpl.java:956) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl.access$1800(ComponentPageElementImpl.java:61) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl$PostRenderCleanupPhase.render(ComponentPageElementImpl.java:443) > at > org.apache.tapestry5.internal.services.RenderQueueImpl.run(RenderQueueImpl.java:72) > at > org.apache.tapestry5.internal.services.PageRenderQueueImpl.render(PageRenderQueueImpl.java:124) > at $PageRenderQueue_135675e1f6b934.render(Unknown Source) > at $PageRenderQueue_135675e1f6b933.render(Unknown Source) > at > org.apache.tapestry5.internal.services.MarkupRendererTerminator.renderMarkup(MarkupRendererTerminator.java:37) > ... > Additionally we experienced a similar issue when using a component with > a mixin annotation in a loop, that was rendered more than 20 times on > the page. > The contention here was on the > org.apache.tapestry5.internal.util.NamedSet.getValues call > > "http-9080-79" daemon prio=10 tid=0x00000000588dc000 nid=0x3e61 waiting > for monitor entry [0x000000004ad98000] > java.lang.Thread.State: BLOCKED (on object monitor) > at > org.apache.tapestry5.internal.util.NamedSet.getValues(NamedSet.java:78) > - waiting to lock <0x00000000e2fa4d70> (a > org.apache.tapestry5.internal.util.NamedSet) > at > org.apache.tapestry5.internal.util.NamedSet.getValues(NamedSet.java:257) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl.mixinForClassName(ComponentPageElementImpl.java:892) > at > org.apache.tapestry5.internal.structure.ComponentPageElementImpl.getMixinByClassName(ComponentPageElementImpl.java:879)mvn > at > org.apache.tapestry5.internal.structure.InternalComponentResourcesImpl.getMixinByClassName(InternalComponentResourcesImpl.java:366) > at > org.apache.tapestry5.internal.transform.MixinWorker$1$1.get(MixinWorker.java:92) > at > biz.toc.buyme.client.webapp.core.components.DHTMLTimer.conduit_get__informalElement(DHTMLTimer.java) > > For the time being we removed the mixin, but on the loop issue I am > clueless. > Any suggestions or tips are very welcomed. > Kind Regards > Robert Lentz > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tapestry.apache.org > For additional commands, e-mail: users-h...@tapestry.apache.org > -- Howard M. Lewis Ship Creator of Apache Tapestry The source for Tapestry training, mentoring and support. Contact me to learn how I can get you up and productive in Tapestry fast! (971) 678-5210 http://howardlewisship.com --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tapestry.apache.org For additional commands, e-mail: users-h...@tapestry.apache.org
