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Performance tuning CLM runtime


Amlan Sengupta (33289) | asked Jan 15 '13, 8:28 a.m.
Server Environment : Windows 7
JDK 1.5.0

We are trying to tune server environment. The following are the recommended tuning on CLM  @

https://jazz.net/blog/index.php/2012/09/10/keeping-my-jazz-server-happy-and-my-users-overjoyed/

Solaris (and even the unsupported MacOS)

-Xmx4g -Xms4g -Xmn512m
-XX:MaxPermSize=768M -XX:ReservedCodeCacheSize=512M -XX:CodeCacheMinimumFreeSpace=2M

  • AIX

-Xmx4g -Xms4g -Xmn512m
-Xgcpolicy:gencon -Xnocompressedrefs

  • Other

-Xmx4g -Xms4g -Xmn512m
-Xgcpolicy:gencon -Xcompressedrefs
-Xgc:preferredHeapBase=0×100000000

Can someone help me understand, as per the following guide why the " other option "  does not work on windows ? All that we could provide was  -Xmx4g -Xms4g -Xmn512m. The rest just prevent the server from starting. The server just does not start up, and neither you would get any thing in the error logs.

I am this specific bit was the cause of the problem.
-Xgcpolicy:gencon -Xcompressedrefs
-Xgc:preferredHeapBase=0×100000000

- Amlan

2 answers



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Karl Weinert (2.0k52736) | answered Jan 15 '13, 9:35 a.m.
JAZZ DEVELOPER
-Xgc:preferredHeapBase is new to Java 6 SR7 see the  Java Diagnostics Guide 6 for more information.
This is new to RTC 4.x but it looks like you may be using a 3.x system based on your JDK

If you are using the version of java that supports these setting the issue can still be the preferredHeapBase  setting. The 100000000 value  tells the JVM to use the heap located at the 4GB mark, leaving the lowest 4GB of address space for use by other processes.  So that means you would need least 8 gigs of memory on the system (based on the 4G xmx setting). From my experience you would need even more since that setting also requires the memory is uses to be contiguous.

Comments
Amlan Sengupta commented Jan 15 '13, 10:56 a.m.

kewl. Thank you very much for the clarification.


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Matt Lennon (61225) | answered Jan 15 '13, 10:47 a.m.
JAZZ DEVELOPER
Hi Amlan.

Windows 7 is not a supported server platform for CLM. Even if you can get it working, we don't recommend you use it in a production environment. See the CLM 3.0.1.x system requirements for details.

    -Matt

Comments
Amlan Sengupta commented Jan 15 '13, 10:57 a.m.

ok. Thank you.

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