IBM WebSphere Application Server

Consider making the following changes in the WebSphere Administrative Console:

• JVM Tuning Parameters

• Servlet Caching

• Thread Pool Size

For more information, see the “IBM WebSphere V5.1 Performance, Scalability, and High Availability WebSphere Handbook Series” at:

http://www.redbooks.ibm.com//Redbooks.nsf/RedbookAbstracts/sg246198.html?OpenDocument

JVM Tuning Parameters

Add the JVM tuning parameters for JVM 1.4.2 shown below, by following these links in the console:

Servers>Application Servers>server1>Process Definition>Java Virtual Machine

Add “-server” as the first parameter in the “Generic JVM arguments” box. Then, add the following entries after the other existing parameters:

-XX:NewSize=336M -XX:MaxNewSize=336M
-XX:+DisableExplicitGC
-XX:+UseParNewGC
-XX:+UseConcMarkSweepGC
-XX:+CMSPermGenSweepingEnabled
-XX:+UseCMSCompactAtFullCollection
-XX:CMSFullGCsBeforeCompaction=0
-XX:+CMSClassUnloadingEnabled
-XX:SoftRefLRUPolicyMSPerMB=0
-XX:+PrintClassHistogram 
-XX:+PrintGCTimeStamps 
-Xloggc:/opt/WebSphere/AppServer/logs/server1/gc.log
-XX:-CMSParallelRemarkEnabled

If you use WebSphere 6.x with Sun JVM 1.5 or later, then some of the garbage collection (GC) algorithms can be safely removed. The following is a list of JVM options that can be used with Sun JVM 1.5 or later.

-XX:NewSize=336M -XX:MaxNewSize=336M
-XX:+DisableExplicitGC
-XX:+UseParNewGC
-XX:+UseConcMarkSweepGC
-XX:+PrintClassHistogram
-XX:+PrintGCTimeStamps
-Xloggc:/opt/WebSphere/AppServer/logs/server1/gc.log
-XX:-CMSParallelRemarkEnabled 

Servlet Caching

Make sure that servlet caching is enabled by checking the checkbox next to “Enable servlet caching” by following these links in the console:

Application Servers>server1>Web Container>Configuration: Servlet caching

Thread Pool Size

Allow the thread pool to grow beyond the maximum thread pool size set by checking the checkbox next to “Allow thread allocation beyond maximum thread size” by following these links:

Application Servers>server1>Web Container>Thread Pool Is Growable