[JBoss-user] [Performance Tuning] - Re: Low CPU Utilization on Linux
Some operations in JBoss or your O/S may not be very parralelizable, blocking the other CPUs. There are tools to find out where your application (or JBoss) may be blocking the other CPUs, such as JProbe or JProfiler. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3891156#3891156 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3891156 --- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf ___ JBoss-user mailing list JBoss-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jboss-user
[JBoss-user] [Performance Tuning] - Re: Low CPU Utilization on Linux
Hi Everyone, Thanks for the responses. I will try to answer all questions to help me get to the bottom of this. By CPU Utilization, I mean we are never seeing all 4 CPUs go above a combined amount of 120%. To illustrate, here are a few "top" printouts: CPU0 states: 15.1% user, 3.3% system, 0.0% nice, 81.1% idle CPU1 states: 15.2% user, 2.4% system, 0.0% nice, 81.2% idle CPU2 states: 6.0% user, 1.2% system, 0.0% nice, 92.1% idle CPU3 states: 64.3% user, 7.2% system, 0.0% nice, 27.3% idle CPU0 states: 7.3% user, 3.2% system, 0.0% nice, 89.0% idle CPU1 states: 6.1% user, 1.3% system, 0.0% nice, 91.4% idle CPU2 states: 1.0% user, 0.4% system, 0.0% nice, 98.0% idle CPU3 states: 83.2% user, 3.4% system, 0.0% nice, 12.2% idle CPU0 states: 6.4% user, 1.1% system, 0.0% nice, 91.3% idle CPU1 states: 12.1% user, 1.4% system, 0.0% nice, 86.0% idle CPU2 states: 3.3% user, 1.3% system, 0.0% nice, 94.2% idle CPU3 states: 76.1% user, 3.3% system, 0.0% nice, 19.4% idle We have 4 CPUs, not 1 Hyperthreaded CPU. We are using the standard Linux JDK 1.4.2 from Sun with the standard VM args in JBoss's run.sh, so as far as I know, we're not using Green Threads. What I'm looking for is something similar to this "top" output (NOTE: not a real output, just something that would be ideal) CPU0 states: 85.4% user, 6.3% system, 0.0% nice, 7.1% idle CPU1 states: 94.4% user, 4.0% system, 0.0% nice, 0.5% idle CPU2 states: 84.3% user, 7.3% system, 0.0% nice, 7.2% idle CPU3 states: 86.2% user, 7.0% system, 0.0% nice, 6.1% idle Is there anything in the JDK or JBoss that consciously prevents us from using all available CPU? Any other ideas or tuning suggestions or light shed is greatly appreciated. Thanks, Joe View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3888958#3888958 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3888958 --- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf ___ JBoss-user mailing list JBoss-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jboss-user
[JBoss-user] [Performance Tuning] - Re: Low CPU Utilization on Linux
jizzoe What king of JVM are you running ? Aren't you running it in green thread mode ? Gozilla View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3888453#3888453 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3888453 --- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf ___ JBoss-user mailing list JBoss-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jboss-user
[JBoss-user] [Performance Tuning] - Re: Low CPU Utilization on Linux
jizzoe; Just so we undestand what the CPU utilization is, can you post a sar -u or a top output ? //Nicholas View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3888440#3888440 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3888440 --- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf ___ JBoss-user mailing list JBoss-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jboss-user
[JBoss-user] [Performance Tuning] - Re: Low CPU Utilization on Linux
I might be guessing but do you have a hyperthreading CPU or do you actually have 4 cpu's. Could this not explain what you observe? View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3888432#3888432 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3888432 --- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf ___ JBoss-user mailing list JBoss-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jboss-user
[JBoss-user] [Performance Tuning] - Re: Low CPU Utilization on Linux
How do you determine CPU utilization? Perhaps it is scaled by the number of processors, so 25% already means maximum usage? Cheers, Jörg View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3888383#3888383 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3888383 --- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf ___ JBoss-user mailing list JBoss-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jboss-user
[JBoss-user] [Performance Tuning] - Re: Low CPU Utilization on Linux
Hi Nickman, Thanks for the response. Yes, we are seeing slowdown, measurably. The CPU goes to 100%, but it's not the expected way. We have 4 processors. Each processor gets up to 25% (never any higher): 100% = 25% X 4. Once this threshold is reached, JBoss crawls. This is observed in a production system for a highly public, well-known, and high-traffic application. This application is middle-ware business logic only (EJBs, POJOs, etc). There is no web server or JSP/servlet load on this box. And it's not very DB intensive. So, the load is sufficient and we have ruled out the DB as the bottle-neck. We have never seen this application (or any other of our production apps running on JBoss) produce a CPU utilization higher than 25% per processor. Any ideas? Has anyone ran into a similar situation? Does anyone have experience running JBoss on multi-CPU box running Linux 9.0? What do you think about the possibility that we may have our thread count too low, so that it could be maxing out our threads, but never fully utilizing our CPUs? As always, any help is greatly appreciated. --Joe View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3888266#3888266 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3888266 --- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf ___ JBoss-user mailing list JBoss-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jboss-user
[JBoss-user] [Performance Tuning] - Re: Low CPU Utilization on Linux
jizzoe; Can you provide more information ? Is the application measurably slow ? If so, how do you know ? If the CPU utlil. is low, perhaps the load you are applying is simply insufficient to keep the boxes busy. If the app is slow, you need to figure out where the botleneck is. Last time I saw this particular symptom, it was a misconfigured NIC on the database server. This was resulting in very slow DB queries, but no visible contention on the app servers or the DB server. //Nicholas View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3888031#3888031 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3888031 --- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click ___ JBoss-user mailing list JBoss-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jboss-user
