Tomcat JVM

Apache Tomcat is a Java application server and is run on a Java Virtual Machine (JVM ).  Typically, each instance of Tomcat is run in its own JVM. Tomcat is capable of running on different JVMs from multiple vendors.  For example, Sun JVM, JRockit JVM, IBM JVM. While many flavors of JVM do exist, majority of users predomnently use the Sun JVM. Tomcat also runs best on Sun JVM.

 

Behavior of Tomcat is often influenced by the JVM configuration. For example, if the JVM is not configured with enough heap space, the web applications running on Tomcat might run into out of memory conditions. In addition, often users set JAVA_OPTS variable which influences the JVM start options. 

 

There are multiple tools available to monitor and manage JVM itself, including VisualVM that is part of the Java Developers Kit.  There are also multiple tools to analyze the Garbage Collector behavior on a JVM. These are helpful during debugging of problems in a development environment.