topic Re: Java and high thread count in Operating System - Linux

Java and high thread count

Coolmar — Mon, 16 Jan 2006 09:40:47 GMT

I really don't know much about java other than it seems to be very resource intensive. The thread count gets up to 70-90 and I was wondering if there was a way to tune it to bring that number down?

thanks,

I have it running for Oracle's OEM on an HPUX 11.11 system

Re: Java and high thread count

Coolmar — Mon, 16 Jan 2006 10:09:05 GMT

Here is the process that I want to tune...is there a parameter in here than I can change to bring the thread count down or to tune it so that it doesn't use so much of the resources?

oracle 2832 2801 0 08:33:05 ? 1:11 /u04/app/oracle/product/OEM/jdk/bin/PA_RISC2.0/java -Djava.security.policy=/u04/a pp/oracle/product/OEM/j2ee/OC4J_EM/config/java2.policy -Djava.awt.headless=true -Xmx1024M -XX:MaxPermSize=256m -Xnoclassgc -DORAC LE_HOME=/u04/app/oracle/product/OEM -Doracle.ons.oraclehome=/u04/app/oracle/product/OEM -Doracle.home=/u04/app/oracle/product/OEM -Doracle.ons.oracleconfighome=/u04/app/oracle/product/OEM -Doracle.ons.clustername=C_x.x.x.x.13bd574.1026a361657.-7fff -Dor acle.ons.instancename=EnterpriseManager0.server3.domain -Dopmn.compatible=904 -Doracle.ons.indexid=OC4J_EM.default_island.1 -Dora cle.ons.uid=782041870 -Doracle.oc4j.instancename=OC4J_EM -Doracle.oc4j.islandname=default_island -DOPMN=true -jar oc4j.jar -confi g /u04/app/oracle/product/OEM/j2ee/OC4J_EM/config/server.xml -properties -properties -ports ajp:3302,rmi:3202,jms:3702

Re: Java and high thread count

Bill Thorsteinson — Mon, 16 Jan 2006 10:38:30 GMT

Java tends to be thread intensive. For
an application such as OEM I would not
expect the thread count to rise so high
unless there are a lot of things scheduled
at the same time. Discuss scheduling with
the DBAs. Do they schedule everything to
run at midnight or some othee majic time.
If so then ask them to spread the load
over a window of time.

Also if they are monitoring a large number of
databases, the thread count may be
proportional to the number of databases.
This is less likely to be a concern.

Re: Java and high thread count

Rita C Workman — Mon, 16 Jan 2006 10:41:20 GMT

I'm no Java or Oracle export. So what I do is tune my kernel to handle the demand.
So you might look at things in that area, cause your right...Java is a hungry beast.

First one I change for Java is max_thread_proc (64 default way too low).

But figuring that might be the one parm that is sitting at default.

Rgrds,
Rita

Re: Java and high thread count

Rita C Workman — Mon, 16 Jan 2006 10:43:34 GMT

...hit enter too soon.

If you want to look at tuning. Let us know your box and how much memory you have. Post your present kernel settings....and I'm sure there are plenty of folks that can provide somet tuning assitance.

Rgrds again,
Rita

Re: Java and high thread count

Steven E. Protter — Mon, 16 Jan 2006 10:52:59 GMT

Shalom Sally,

For java to work right with Oracle the patches listed in http://www.hpux.com/go/java need to be installed along with dependencies. They are not necessarily included in quarterly patch bundles.

SEP

Re: Java and high thread count

Srini Jay — Mon, 16 Jan 2006 11:42:58 GMT

I would use HP jConfig tool to find out all Kernel parameters that needs to be changed for the version of Java that is installed & ofcourse it suggests values based on your HP UX server hardware.

You can download the tool from http://www.hp.com/products1/unix/java/

Re: Java and high thread count

Coolmar — Mon, 16 Jan 2006 13:56:35 GMT

thank you Srini! That jConfig tool really helped.