[jboss-user] [Performance Tuning] - Re: Slower JBOSS 4
Have you had any luck in your research? We ourselves took a big performance hit when we upgraded to 4.x, although we made several new deployments at the same time that could be part of our decreased performance too. Here are a couple of links you might have already seen - if not, they are helpful. A JBossian blog posting on rmi gcinterval and also stack size: http://blogs.jboss.com/blog/acoliver/2006/03/21/If_you_dont_do_this_JBoss_will_run_really_slowly.txt Sun's JBoss On Solaris Best Practices http://www.sun.com/servers/coolthreads/tnb/applications_jboss.jsp Here's an extensive article on slimming your jboss installation. It starts with tuning tips http://wiki.jboss.org/wiki/Wiki.jsp?page=JBossASTuningSliming And you probably know this one too, but just in case: http://java.sun.com/docs/performance/ Along with this: http://java.sun.com/docs/hotspot/gc5.0/gc_tuning_5.html If you haven't yet already, check out http://java.sun.com/j2se/1.5.0/docs/tooldocs/share/jstat.html#gcutil_option I use that on production boxes instead of verbosegc And jmap with the -heap option is awesome. The -histo option is pretty cool too. View the original post : http://www.jboss.com/index.html?module=bbop=viewtopicp=4032147#4032147 Reply to the post : http://www.jboss.com/index.html?module=bbop=postingmode=replyp=4032147 ___ jboss-user mailing list jboss-user@lists.jboss.org https://lists.jboss.org/mailman/listinfo/jboss-user
[jboss-user] [Performance Tuning] - Re: Best JVM memory size?
Thanks Peter, Very interesting... I'll experiment with the premise that if a certain percentage of the heap is swapped, it's OK, because it will not be used anyway. View the original post : http://www.jboss.com/index.html?module=bbop=viewtopicp=4019330#4019330 Reply to the post : http://www.jboss.com/index.html?module=bbop=postingmode=replyp=4019330 ___ jboss-user mailing list jboss-user@lists.jboss.org https://lists.jboss.org/mailman/listinfo/jboss-user
[jboss-user] [Performance Tuning] - Re: JBoss Performance Tuning
I'm sure everyone here would like to see your JVM options to start with... HOWEVER, since you have a JBoss service contract, please open up a case with them and mark it as a Production is down. They should be calling you pretty quickly, and if they don't then you should call them! Needing to limp along and re-boot your servers once an hour is pretty awful. Jerry View the original post : http://www.jboss.com/index.html?module=bbop=viewtopicp=4019551#4019551 Reply to the post : http://www.jboss.com/index.html?module=bbop=postingmode=replyp=4019551 ___ jboss-user mailing list jboss-user@lists.jboss.org https://lists.jboss.org/mailman/listinfo/jboss-user
[jboss-user] [Performance Tuning] - Re: JBoss Performance Tuning
You can also use jmap with the -heap option to check your permgen. It will give you a listing of different areas of the jvm memory footprint, permgen is at the bottom. It's a quick way to take a look. You run it with jmap -heap jboss jvm pid For instance: /usr/jdk1.5/bin/jmap -heap 7302 | ... | Perm Generation: |capacity = 134217728 (128.0MB) |used = 79881104 (76.18055725097656MB) |free = 54336624 (51.81944274902344MB) |59.51606035232544% used | On this box min and max permgen is set to 128M. If you don't have them both set to the same value (aka pre-allocated), jmap will tell you what value was being used when you ran the command - the value will be capacity. In my case, someone had set the box to 300M for permgen. Checking with jmap -heap over a weeks period made me realize that 128M was enough for this box. View the original post : http://www.jboss.com/index.html?module=bbop=viewtopicp=4019100#4019100 Reply to the post : http://www.jboss.com/index.html?module=bbop=postingmode=replyp=4019100 ___ jboss-user mailing list jboss-user@lists.jboss.org https://lists.jboss.org/mailman/listinfo/jboss-user
[jboss-user] [Performance Tuning] - Re: Best JVM memory size?
Peter, I'm a bit confused by your answer, that if you have 1 gig of ram on a box it's ok to set the heap to 1 gig. Through reading your other postings I know that you have coded your own JVM based on Sun's source, so you know your stuff. And I know that you know the heap is just the new and tenured gen, not the whole JVM. Hopefully you can clear something up for me. We run JBoss on Solaris. I have a basic formula that I use for my JVM memory calculations which is: Total JVM memory footprint = JVM housekeeping + heap + permgen In the formula above: * JVM housekeeping (this is my own stupid term) = native code + JVM runtime data (code cache, etc.). * heap = new gen + tenured gen * permgen = permgen When I run a prstat on the JBoss pid, what I see for SIZE is Total JVM mem footprint. I can do my little calculations with stats that I get from jmap -heap and come up with consistent sizes for JVM housekeeping across our boxes, depending on the particular deployment (and other things like # of threads). In our case, we pre-allocate (set min=max) for heap and permgen. I haven't yet found a option specifically for setting memory for the native code or runtime data, I don't know if anyone would want to. Anyway (there really is a question buried here :), if you have a 1 gig box, preallocate 1 gig for heap (new and tunured), preallocate 128 or whatever for perm, knowing that the native code and runtime data might want 200 or 300 meg, aren't you going to be living in swap city? I'm going to have to test this out. I've been leaving 500 meg free on our Solaris boxes for the OS and the monitoring stuff the network guys run. Thanks, Jerry View the original post : http://www.jboss.com/index.html?module=bbop=viewtopicp=4019119#4019119 Reply to the post : http://www.jboss.com/index.html?module=bbop=postingmode=replyp=4019119 ___ jboss-user mailing list jboss-user@lists.jboss.org https://lists.jboss.org/mailman/listinfo/jboss-user
