tomcat performance

[Former Member]

Users,

I have been trying to enhance the tomcat performance on BOXI3.1 set-up. Based on recommendations in the forums

i have set it up in Tomcat Configuration -> Java as

Initial Memory Pool 1024

Maximum Memory pool 1024

Thread stack size 256

through the graphical interface. Now my machine has ample GB and i want to increase this. However the tomcat/VM does not start if i increase say Max memory pool to 2048 etc.

It just says "Unable to initiate virtual machine" in it's logs.

Can some one provide me suggestions on how we can optimize tomact?

Thanks

[former_member189544 · Accepted solution]

Hi!

This is not a Tomcat/JVM issue but more a OS issue.

Interesting Cites from sun-forum:

"The limit will be a function of many variables: the physical RAM in the machine, what drivers are loaded and are grabbing physical and/or virtual address space, the size of the JVM executable and associated DLLs (which will be influenced by whether you're using any libraries that make use of JNI), the processor architecture (Intel/AMD, 32bit/64bit), the version of Windows, whether you've started it with the /3GB flag, if the BIOS has shadowed any hardware (e.g. graphics), if your graphics card uses any main memory or exclusively it's own memory, the vendor and version of your JVM, etc., etc.

In short, there are far too many variables for there to be a definite answer to this, so you'll just have to try different values until you hit the limit."

""http://msdn.microsoft.com/en-us/library/aa366770(VS.85).aspx" came to my rescue. Now, it can be determined just before starting tomcat, about the available physical memory that tomcat can hog. And I realise, that this was more of an OS query, than a Sun Java one ..."

So afterall you need to tweak your system individually. Usually on Windows OS I would try somthing between 1024 and 1536 MB (On my system it's 1344 MB e.g.).

If you need more, you should consider clustering/loadbalancing two or more Tomcat instances ideally on a *nix-box or more than one Windows box...

Regards,

Harald