Overhead of many Threads?

[egrath]

Hi there,

Does anyone know if there is a performance impact in Windows 2000/2003 when a Application uses many, many Threads?

We have a Java based Client-Server Application which on the Server Side consists of about 40 concurrent running Java Processes - most of them are running with 100-200 Threads per Process and about 4 Processes are using about 1700 Threads each.

The entire Java Application runs with approximatly 7000-8000 Threads.

Performance of the Application was never very good, but we want to find out why. Would it be possible that the Context switching between the many running threads could be a performance hole?

The spec of the machine running the Application is:

HP DL580 Server

Windows 2000AS/2003EE OS (some servers run 2000, some 2003)

4 XEON's with HT

6 GIG of RAM

/PAE enabled

Application uses JRE 1.3.1

Each server serves about 300 concurrent users

Bye, Egon

[Gurgelmeyer]

7000-8000 threads is definately too much.

It's not just a w2k/w2k3 issue - it's a common Java issue. I went to a presentation at Sun Microsystems awhile back, and they told us explicitly that reducing the number of threads in scenarios like this was one of the the best ways to improve performance. Somewhere at sun.com there's a profiling tool - but I don't remember its name I'm afraid.

Best regards

Gurgelmeyer B)