Maximizing Servlet Performance

Consider the following guidelines for improving servlet performance:

• Increase the Java heap size to help garbage collection. The Java heap size can be adjusted by adjusting the values specified to the —Xms and —Xmx jvm- options in server.xml. For example, <jvm-options>-Xms128m-Xmx256m</jvm-options> sets the minimum Java heap size to 128 MB and 256 MB. For more information, see Sun Java System Web Server 7.0 Update 2 Administrator’s Guide.

  For information on tuning the Garbage Collector see, Managing Memory and Garbage Collection in Sun Java System Web Server 7.0 Update 2 Performance Tuning, Sizing, and Scaling Guide.

• Set the stack space if applications use deep recursion, or in any cases where very complex JSP pages are used.

  You can set the stack space using set-thread-pool-prop wadm command. For example, $wadm set-thread-pool-prop [other args] stack-size=544288. For more information, see Sun Java System Web Server 7.0 Update 2 NSAPI Developer’s Guide.

• Use the NSAPI cache improve servlet performance in cases where the obj.conf configuration file has many directives. To enable the NSAPI cache, include the following line in magnus.conf:

  Init fn="nsapi-cache-init" enable=true

• Check whether the session ID generator that is used for servlet sessions employs cryptographically unique random number generation algorithms. This method might present a performance problem on older, slow machines. For more information, see Chapter 6, Session Managers.

• Reduce the number of directories in the classpath.

• Disable dynamic reloading.

• Disable the Java Security Manager.