To many thread

[pascallambert]

Hi,

We have the following problem with one of our client: After a few day the JVM for JBoss fork too many java process and finish by hanging JBoss.
Yesturday we reach 1037 java subprocess.

Here is the client environement:
JBoss 3.2.1(200305041533)
Java HotSpot(TM) Server VM (build 1.4.1_01-b01, mixed mode)
Linux version 2.4.18-3 (Red Hat Linux 7.3 2.96-110)

By the way i noticed that one another Linux server we have, the JVM doens't create subprocess for thread (Linux version 2.4.20-8 (Red Hat Linux 3.2.2-5)). Does anybody know what make the JVM use thread in the same process vs use process fork?

[gorano]

I'm not confident enough to answer your question straight away, but I did
some reading on linux threading and JVMs before we built one production server.

Linux added NPTL (Native POSIX Thread Library) from version 2.6.x. This thread library is a much better implementation than the previous thread lib. You get NPTL in Redhat 9.x- (2.4.x + patches).

To be able to take advantage of the new thread library you also have to use J2SE 1.4.2-.

This combination above should give a lot better thread scalability,
especially fo a J2EE server (lot of threads).

You will find more info on linux + JVM threads at

http://java.sun.com/developer/technicalArticles/JavaTechandLinux/RedHat

/Goran