To increase the Java heap size in Tomcat, follow the instructions below:
- Open the startup script used to start Tomcat. For Windows servers, this will be catalina.bat. On Unix servers, this will be catalina.sh.
- At the top of the script, define the JAVA_OPTS variable to specify a maximum heap size of 256MB. For example:
- Windows: set JAVA_OPTS=-Xmx256m
- Unix shell: JAVA_OPTS=-Xmx256m
The following image shows an example of setting the JAVA_OPTS variable in the catalina.bat (Windows) file.
- Save the changes and startup/restart Tomcat.
In recent versions on Windows, you can instead set this in the Tomcat interface:
- Go to Start=> All Programs => Apache Tomcat x.x => Configure Tomcat.
- Go to the “Java” tab and specify a maximum memory pool:
- Save the changes and startup/restart Tomcat.
Remember that the memory used will decrease available RAM on the machine. This may lead to performance issues if set too high, so set the value with care.
For additional information on optimizing Tomcat memory usage, refer to the following:
http://jakarta.apache.org/tomcat/faq/memory.html
WARNING:
Backup the script before any modifications.
