Stability and Performance - Oracle WebLogic Server 12c Advanced Administration - page 223

Choosing the JRockit garbage collection
mode
Some WebLogic Administrators consider JVM tuning as the top tuning recommendation
for WebLogic. But nowadays, with the newer JVM releases, just setting -Xms and -Xmx
arguments and leaving the GC with default throughput GC mode, should be fine for most of
the WebLogic applications. Since R28, the Oracle JRockit behaves very well out of the box
and, in the majority of the cases, more advanced JVM tunings are not necessary.
There are some situations where a specific WebLogic application could not wait for a full
GC that lasts more than a few seconds. In this recipe, the GC mode will be changed to the
pausetime mode for this particular application.
Getting ready
A JVM startup argument will be added, by using the Administration Console, so make sure
the Administration Server is running.
How to do it...
To change the JVM garbage collection mode:
1. Access the Administration Console by pointing your web browser to
http://adminhost.domain.local:7001/console .
2. Click on the Lock & Edit button to start a new edit session.
3. Expand the Environment tree to the left and then click on Servers.
4. Click on the PROD_Server01 link and then click on the Server Start tab.
5. Add the following to the Arguments field and click on the Save button:
-Xgc:pausetime
6. Click on the Activate Changes button.
7. Restart PROD_Server01.
8. Repeat the preceding steps for Managed Servers PROD_Server02, PROD_Server03,
and PROD_Server04.