WAS: JVM parameters for application server
Hello Team,
Recently, we upgraded CLM 5.0.2 to CLM 6.0.5 (Distributed Topology) and along with that we have WAS 9.0.0.7 and DB2. We are using applicaitons like CCM, RM, QM, DM, Rational Insight and each servers having 128GB of RAM. While configuring WAS JVM properties -Xmx -Xms we configured with 64g in each applications, for effective change we need to Stop and Start the WAS. After stopping the WAS we were not able to Start the WAS again and we checked the log file and it mentioned 64g is too large. As of now we configured JVM properties with 24g in each applications.
My question is, How to utilise that 128GB RAM? What will be the reason for the log message "64g is too large"? Compare to 128GB RAM, -Xmx24g -Xmx24g is very low and also accessing applications will be low.
Any Solution...
Regards,
Kiran
3 answers
Hi Kiran.
The max memory you can set is 24Gb.
- Set the max and the minimum heap values to the same value, and use a heap of no less than 4G (and no more than 24G). By keeping the max and min heaps at the same value, you reduce the work which the JVM would otherwise do to shrink the heap.
See the documentation at https://jazz.net/wiki/bin/view/Deployment/CLMSizingStrategy60
Comments
Note that RAM is not only used by the JVM. RM uses RAM and disk in a different way compared to CCM.
Please also note that we recommend to not install all applications on one machine: https://jazz.net/wiki/bin/view/Deployment/StandardTopologiesOverview
Hello Leonardo,
Thank you for the reply.
Is there any specific reason or statement for configuring JVM properties to 24g and not more than that.