Hello Nathan, I just finished writing a alternate UberspectImpl based on our own MethodCache implementation. I'll let you know if we notice any significant changes in performance.
Ray PS: We had already done some tweaking to use ConcurrentHashMap and removed some sync blocks in the cache... but we still hit a bottleneck. On Thu, 2008-07-24 at 22:02 -0700, Nathan Bubna wrote: > On Thu, Jul 24, 2008 at 2:53 PM, Raymond Auge <[EMAIL PROTECTED]> wrote: > #snip() > > Under heavy load we hit a max throughput and thread dumps during this > > time are completely filled with BLOCKED threads as bellow: > > > > [snip] > > "http-80-Processor47" daemon prio=10 tid=0x00002aabbdb90400 nid=0x5a59 > > waiting for monitor entry [0x0000000044c72000..0x0000000044c74a80] > > java.lang.Thread.State: BLOCKED (on object monitor) > > at > > org.apache.velocity.util.introspection.IntrospectorBase.getMethod(IntrospectorBase.java:103) > > - waiting to lock <0x00002aaad093d940> (a > > org.apache.velocity.util.introspection.IntrospectorCacheImpl) > > at > > org.apache.velocity.util.introspection.Introspector.getMethod(Introspector.java:101) > #snip() > > I do find it interesting that there is so much blocking going on at > this particular point. I didn't appearing all that high on any of the > profiler outputs yet. Perhaps that's just oversight on my part or > perhaps that may be because of the heavy evaluate() use in this > particular case, but still, if we can find a way to speed it up, that > would be good nonetheless. I'll look into it a bit. It may turn out > to be another spot that mostly needs to wait for the JDK 1.5 > concurrency classes, but perhaps there is something that can be done. > I do notice right off the bat that the synchronization of the get() > and put() methods of IntrospectorCacheImpl seems unnecessary as they > are being used within a block synchronized on their instance. With > re-entrant synchronization that might not make a big difference, but > it's something. I bet we could also be more fine-grained here and > synchronize on something like the Class being introspected. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > ---------------------------------- Raymond Augé Software Engineer Liferay, Inc. Enterprise. Open Source. For Life. ---------------------------------- Liferay Meetup 2008 – Los Angeles August 1, 2008 Meet and brainstorm with the creators of Liferay Portal, our partners and other members of our community! The day will consist of a series of technical sessions presented by our integration and services partners. There is time set aside for Q&A and corporate brainstorming to give the community a chance to give feedback and make suggestions! View Event Details Register Now
