Hello all, @Pierre, thanks for pointing out JVisualVM. It looks like an excellent tool, but it doesn't expose any API that I can use in order to programmatically monitor the behavior of OSGi bundles or do some further analysis on the collected data.
Since Cliff and Ali also showed some interest in this topic, I thought I would discuss the results of my search for the past couple of days here to also benefit from your bright minds and come up with some solutions on how bundle profiling could be implemented for a SPEC 4.2 compliant OSGi framework. I examined some of the most up to date profiling tools, namely, JProfiler, JProbe, JVisualVM, JPI, JRockit Mission Control, and YourKit. The first three are proprietary and do not expose any API. JRockit Mission Control is free and has some sort of an API that could be used for profiling, but it only works with JRMC and when I ran felix against it, it drastically slowed down the performance of my application. JPI profiling results would only give me information on org.osgi.framework classes and nothing else! Not sure if this is because of having several class loaders for different bundles or whether there is something else confusing JPI. YourKit is apparently the only one which comes with an API but it does not provide monitoring at a level as fine-grained as JVisualVM (as Pierre said one can monitor processes in JVisualVM at the level of methods, classes, or packages, making possibly to cherry pick the classes or packages and associate them with bundles). I think what I am going to do is to write a bundle that would incorporate YourKit's API so that I can examine how closely I can resemble the behavior of a target bundle by monitoring its behavior as a matter of combining collected information from YourKit and information received from the BundleContext. So it would be like, inspecting the internal of a bundle by reflection and then matching them against the results of thread stack trace from the profiler. Do you guys have any better suggestion? @Cliff, I agree that thread pooling per bundle is an expensive task (specially with what YourKit offers, I have to inspect the thread stack trace in order to pool out the information that I require), but I couldn't think of any other way that would allow me to establish the associations between a process and its source bundle. so, I couldn't think of any alternative to what was suggested in the masters thesis I referenced earlier in this thread. Do you have a better idea? I mean, even if there is going to be a Profiling RFC for the next OSGi Spec, what could it be (considering what JMX offers)? I am asking cause I might be able to somehow try it in my code and get some hints about how it may work. thanks guys and sorry for the long email. your thoughts and suggestions on this matter are very much appreciated of course. -Nima On Fri, Feb 19, 2010 at 8:48 AM, Ali Naddaf <[email protected]> wrote: > I am also interested in knowing what one can do there. I have read that J9 > has some extensions that enables a granular control of resources (memory, > CPU) at the bundle level and ProSyst folks have some management tools around > that but that is the only JRE that I have heard whcih has that kind of > capability, and of course that is not a universal feature of JREs so won't > help most people. > > > On 2/19/2010 10:40 AM, Clifford H. James wrote: > >> I had wondered the same thing and at the time of my search all I found was >> that thesis project that you mentioned below. Let me know if you find >> anything because this is an area that I think needs some attention (perhaps >> from the OSGi Alliance people in an upcoming spec?) but I'm not sure if the >> "ThreadPool per bundle" that the author took doesn't create more troubles >> than it's worth -- it certainly isn't an unintrusive way to monitor bundle >> resource consumption. >> >> ~Cliff >> >> Nima Kaviani wrote: >> >>> Hi all, >>> >>> I wonder if anybody knows of any profiling library / API that would allow >>> me >>> to monitor the CPU and memory usages at a bundle level of granularity? >>> >>> I have already looked into JProfiler, but there are two problems with >>> JProfiler. It is not a free tool, and also its profiling happens the >>> level >>> of objects and packages (the second issue could have been resolved if I >>> could play around with the source code of course). I also found this >>> thesis >>> (http://www.vtt.fi/inf/pdf/publications/2008/P685.pdf) which takes a >>> rather >>> intrusive approach in modifying the internals of an osgi framework in >>> order >>> to support resource monitoring and profiling. Any help along this line is >>> very much appreciated. >>> >>> thanks, >>> -Nima >>> >>> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [email protected] >> For additional commands, e-mail: [email protected] >> >> > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > -- http://nima.magic.ubc.ca
