Tuning the JVM

The JVM executes the byte codes in Java class files, so tuning the JVM significantly affects the performance of applications you deploy on a server. Oracle recommends that on a Windows or Linux platform you use the Sun JDK with the HotSpot Client JVM for development work and the Oracle JRockit JDK for production usage, due to its superior performance. You can switch to a different JVM by simply specifying different values for the JAVA_HOME and JAVA_VENDOR variables and restarting the server. The JAVA_HOME variable points to the top directory of the JDK you want to use. You set the JAVA_VENDOR variable to the value Oracle if you're using the JRockit JDK and to Sun if you're using the Sun JDK. In the following sections, you'll learn how you can tune the JRockit JVM.