Hi, On 30.09.2010 09:31, Ian Boston wrote: > > On 30 Sep 2010, at 07:23, Felix Meschberger wrote: > >> Hi, >> >> On 29.09.2010 22:00, Ian Boston wrote: >>> Hi, >>> Is it possible to register a filter before the SlingMainServlet ? >> >> Short answer: No. >> >> Longer answer: The SlingMainServlet (or actually the >> SlingRequestProcessorImpl these days) is controlling the execution of >> the filters and those are only called once the SlingHttpServletRequest >> and ..Response objects have been properly set up including resource and >> script to be called. > > > 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 ? > > 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 ... 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). Probably we have such contentions in Sling, too (would not surprise me), and we should work on that. Regards Felix > > I am going to try and trace through the code base to see if there is anything > that could be making the requests single-threaded, but as a quick fix I > wanted to get the caching filter right out in front. > > Now, its possible that some of the mods I have are causing the problem, so, > here is a dumb question: > > Has anyone tested Sling OOTB for GET concurrency and if so, do they see > single threaded behaviour or does it show linear ramp up upto the number of > cores ? > > > Ian > > (I am assuming that Jetty is highly concurrent, but I might need to check > that in a PAX environment). > > >
