User Guide
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The configuration options described elsewhere in this user guide can be set to optimize BEA JRockit JVM performance with both BEA WebLogic Server and BEA WebLogic Workshop. This chapter defines these optimal settings and discussed how to use the JVM with these applications. It includes information on the following subjects:
BEA JRockit JVM is certified for use with BEA WebLogic Server. This section includes information on the following subjects:
For details on certified and supported platform combinations of WebLogic Server with BEA JRockit 8.0, please refer to the following Web pages:
http://www.bea.com/products/weblogic/server/
http://www.bea.com/products/weblogic/jrockit/
BEA JRockit is the default production JVM shipped with WebLogic Server, although you can use another VM, such as Sun Microsystem's HotSpot JVM as a development VM. To ensure that BEA JRockit is the JVM running with your instance of WebLogic Server, at the command line, type:
java -version
If BEA JRockit is running, the system will respond:
java version "1.4.2_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_04-b05)
BEA JRockit(TM) 1.4.2_04 JVM (build ari-29212-20040415-1348-win-ia32, Native Threads, GC strategy: parallel)
Note: This example assumes you are using the native thread method (the default) and generational concurrent garbage collector (default when maximum heap size is larger than 128 MB).
If you are starting BEA JRockit JVM from the WLS Node Manager, you need to enter the fully-qualifying path, as shown above, in the Java Home field on the Remote Start Page; for example:
\bea\jrockit81_141\bin\java
You can enable the management server from the WLS Node Manager by doing the following:
For more information on using the Node Manager, please refer to the Overview of Node Manager in Configuring and Managing WebLogic Server.
If you started the server or cluster of servers with the Node Manager and specified an absolute pathname to BEA JRockit JVM's top-level directory in the Java Home field on the Node Manager's Remote Start page, you can set any option from this page, too. Simply enter the option and any arguments in the Arguments field.
For more information on using the Node Manager, please refer to the Overview of Node Manager in Configuring and Managing WebLogic Server.
The parallel garbage collector strategy is used by default (set explicitly with -Xgc:parallel
). If you want to improve BEA JRockit performance, you can try one of the following techniques, bearing in mind that all applications are different and you need to verify which settings give the best performance in each case:
-Xms
) and maximum heap size (-Xmx
).-Xgc:singlecon
) or generational concurrent (-Xgc:gencon
). Remember to set the nursery (-Xns
) explicitly to ~12% of the maximum heap size when using the gencon strategy, the default nursery size is by default 10 MB/CPU, which is often too small for the average server application.Note: The parallel strategy is single generational and the -Xns
setting will have no affect on processing (see Setting the Size of the Nursery ).
For more information on tuning BEA JRockit, please refer to Tuning BEA JRockit JVM.
If you run WebLogic Server with BEA JRockit JVM, you can use the WebLogic Server Administration Console to view runtime data about the VM and the memory and processors on the computer hosting it.
To monitor BEA JRockit JVM, do the following:
The JRockit tab displays monitoring information.
To view additional data about BEA JRockit, such as how long it spends in a specific method, use the BEA JRockit Management Console, as described in Using the BEA JRockit JVM Management Console.
When you switch to BEA JRockit JVM in WebLogic Server, any changes to the VM and start-up setting, should be handled by the WLS Configuration Wizard. Additionally, if any installation-wide scripts must be updated due to the switch, these will also be handled by the WLS Configuration Wizard.
Among information that needs to be changed when switching to BEA JRockit JVM are:
JAVA_HOME
variable needs to be changed to the absolute pathname to the top BEA directory; for example, c:\bea\jrockit81
. You can also change the JAVA_HOME
variable from the Node Manager's Remote Start page by entering the absolute pathname in the Java Home field.
JAVA_VENDOR
variable to BEA
.You will also need to restart any servers that are currently running.
For complete details on switching to BEA JRockit JVM from another JVM, please refer to Migrating to BEA JRockit. For more information on using the Configuration Wizard when switching to BEA JRockit, please refer to Changing the JVM that Runs Servers.
To switch the virtual machine when WebLogic Server is running as a service, do the following:
(HKEY_LOCAL_MACHINE/SYSTEM/ControlSet001/Services/{ServiceName}).
If you are running JRockit with BEA WebLogic Workshop, we recommend that you use the same configuration parameters specified for WebLogic Server in Tuning BEA JRockit for WebLogic Server.
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