Dual Processor Config

[cbax007]

Is there anything special I need to do within JBoss to make it take advantage of two processors on a dual proc box? I'm running some load testing against a JBoss 4.2.2 instance and it doesn't look like it's utilizing both cpus.

[peterj]

No, there is nothing special you need to do to get JBossAS (or any Java app for that matter) to use multiple processors.

What OS are you running? Is there any setting in the OS that might limit apps to specific processors? I vaguely recall someone having this issue with Solaris.

[cbax007]

It's a Linux box. I have to check with the network team to see what version of the OS it's running though.

[peterj]

I have run JBossAS on multi-proc systems running Ubuntu, RedHat, and SUSE. I have no problems keep multiple procs busy. What testing are you doing to gauge processor usage? At work we run standard benchmarks, but I also run JMeter with various web apps; usually 10 simulated users is enough to keep 2 processors very busy.

[moousa]

I have the same problem but I do not know what I should do. I use an application that is running on a jboss 4.2.2 server. I noticed that jboss uses only one processor all the time although I have a machine which contains 4 processors. I search on internet but I found no help.
my question is there a way to run Jboss on multiple processors to take advantage of all my resources.

I'm using an AMD64 machine with 4 processors and jboss is running on lunix CentOS 64bit .

[peterj]

Is there some OS config setting that is preventing JBoss AS from using all procs? I have a quad-core desktop on on both Vista and Ubuntu I can get JBoss AS to use all four cores.

Also, how are you determining that JBoss AS is using one one processor? The startup tends to be single-threaded because of the way deployment is done. But HTTP access in multi-threaded to under load you should see a lot of multi-processor usage.

[moousa]

When I look at the CPU usage I see that it never exceed 100%, except at the startup, the CPU utilization may reach 170%.

I installed several scripts in order to record the load average of CPUs, memory usage... but all the time, only one cpu is busy. What is the kind of tests that I should do to make sure that jboss take advantage of all the processors of the machine?

thanks for your help.

[peterj]

What tool? top?

The 170% should be a clue that JBoss AS is actually using more than one CPU. Also, unless you place JBoss AS under heavy load you might not see CPU usage go above 100%.

Both Gnome and KDE have tools you can use to monitor usage of individual CPUs. If you use those, you should see that all CPUs are used.