Input appreciated and respected, however I think to help Peter we need to keep off the performance bunny hole. He never said performance was his problem.
As a side note, you're right: what you tested (startup time) was far from a valid performance benchmark. JVMs intended to boost server performance don't try to be fast for startup times (if you want that, use the -client jvm option, not -server). They care more about being fast for things servers care about after they're already up and running - like handling multiple threads quickly, optimizing server hotspots like network connections, and effective memory management of large heaps under load, etc. Besides, I take benchmarks with a grain of salt - each custom app does different things, and thus it's impossible that a generic benchmark is going to tell you what you really need to know - how does tool A stack up against tool B with YOUR application...
Oh shoot, now you got me goin' down the bunny hole. Seriously, Peter - my guess is you've either got a resource leak or an inappropriate resource configuration. Start by looking at file descriptors.
Just my 2 cents (again), David
Rod Macpherson escribió:
Downloaded JRockit and launched a large J2EE application in debug mode. JBoss started in 1:24. Using Sun's JDK 1.4 JVM the same application started in 1:32. I would call that a noise-level improvement given JRockit is a commercial product focused on performance. Not a valid benchmark but then if your compiled code is really all that you would expect to see more than a fraction of 1% improvement. Conclusion: JRockit is not worth the disk space it's sitting on:)
-----Original Message----- From: David Ward [mailto:[EMAIL PROTECTED] Sent: Thu 12/4/2003 6:28 PM To: [EMAIL PROTECTED] Cc: Subject: Re: [JBoss-user] JBoss On Linux
Peter, I've read others' responses to your problems, and they all seem to be addressing the wrong thing: performance. What you describe does not sound like a performance problem (neither of speed nor memory management). You never said the app was slow, so why do you care about "SPECjAppServer2002 benchmarks" and the like? It sounds more like a resource leak to me, my first guess being of file descriptors. On Linux/UNIX based systems, socket connections (like to your mailserver and database) - not just files - use file descriptors. If that's the case, something - or a growing number of "things" - are holding onto sockets or files (same thing to UNIX) and not letting go. If I were you I would do 2 things: 1) In the short term, increase your system setting for max # of file descriptors (in my experience, OS defaults are stunningly low for production systems). This will require a system reboot to take effect. 2) Find out where your resource leak is. It may be there's one in your application (that runs in jboss), and then the cron runs that might require a lot of descriptors too. Together, they could use up to your limit. To diagnose this you might have to employ more than just one tool. netstat (comes with Linux/UNIX), filemon (http://www.sysinternals.com/linux/utilities/filemon.shtml) , Optimizeit (http://www.borland.com/optimizeit/optimizeit_profiler/), etc. Last, maybe there really isn't a leak, but the nature of your application, plus the crons that run at specific times, just simply require more file descriptors than what your system has configured. Upping that value might prove to be all you need to do. If it never grows past that max, you're set - no leak. Unfortunately, without doing some surfing, I can't tell you where to set it for your system, or what the best value should be. I'll leave that as an exercise for you. ;) Anyway, hope this helps. And sorry in advance if it ends up leading you down the wrong path. I just wanted to share what your problem "smelled like" to me. David Peter Luttrell escribió: > We're using JBoss3.2.1 with Jetty on RedHat 9 with Suns 1.4.2_01 vm. We > have a pretty heavy load. > > After roughly a week many of the boxes start to experience weird > problems where JBoss is unable to get what looks to be socket > connections. In some cases, we cannot contact our mailserver, in other > cases we cannot contact our database; in the latest case we're unable to > get a connection to the local jndi server (localhost:1099). Sometimes a > simple restart of jboss will sometimes solves the problems, othertimes > we have to restart linux. The times of the crashes are roughly 4am and > sometimes 6am, so it's likely caused by a cron job running at those > times, which we're currently looking into. Has anyone experienced > similar problems? > .peter > > ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id78&alloc_id371&op=ick _______________________________________________ JBoss-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-user
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