On 30 Sep 2010, at 09:15, Felix Meschberger wrote: >> >> Ok, (& btw, thanks for the other pointers). >> The reason I want to register the filter before Sling is the caching one >> captures certain public responses before any processing and so should be a) >> highly concurrent with the right cache and b) lightweight. > > Yes, I agree, that caching should be done as early as possible .... And > to get most performance doing it before resolving the request resource > and the servlet/script is probably a must. > > This reminds me of other discussions we had around caching and the > question, whether it would be usefull to have a hook in the > SlingMainServlet (or its helpers) to plug cache functionality ?
That would make sense, I will look into a patch. > >> >> I dont know if its my machine or the way of testing but at the moment I can >> only get a max of 600 request per seconds on a json properties GET, flat >> regardless of concurrency out of sling. If I test Tomcat 6 on a html page I >> get 6K/s and the throughput appears to have some relationship to the >> concurrency of the requests. > > I don't want to start finger-pointing, but ... me neither, I just want to get a fix in place before it becomes a problem for us. (and any one else). > > It looks like Jackrabbit has some issues with concurrent reads. > > Setting up a test with a Java profiler allowing to measure thread > contention (synchronization stuff) would probably show a hint (IIRC > YourKit Profiler has such functionality). Good pointer, they were kind enough to give me a license of OS work. > > Probably we have such contentions in Sling, too (would not surprise me), > and we should work on that. Ok I will look into it. One more point of reference data. A Servlet registered in OSGi using the Pax Web service has almost identical performance and concurrency compared to a Jetty instance OOTB. In order of 2K request/s single threaded rising to 5K request/s at 5 concurrent threads, but that is almost certainly fighting for OSX thread resources on my box. So this narrows the problem down to within the SlingMain Servlet and beyond, I will look at that next. Thanks Ian > > Regards > Felix
