How to increase Java heap space for a tomcat app

Question

There are lots of questions that ask this or a similar question. They all give the command that has to be executed, what I don't understand is where do I write this command. I want to permanently increase the heap space for my tomcat apps. I read this page http://javahowto.blogspot.com/2006/06/6-common-errors-in-setting-java-heap.html and it says under the Tomcat section Stop Tomcat server, set environment variable CATALINA_OPTS, and then restart Tomcat. Look at the file tomcat-install/bin/catalina.sh or catalina.bat for how this variable is used. For example, set CATALINA_OPTS=-Xms512m -Xmx512m (Windows, no "" around the value) export CATALINA_OPTS="-Xms512m -Xmx512m" (ksh/bash, "" around the value) setenv CATALINA_OPTS "-Xms512m -Xmx512m" (tcsh/csh, "" around the value) So I replaced the line set CATALINA_OPTS= with set CATALINA_OPTS=-Xms512m -Xmx512m But I still get the error. javax.servlet.ServletException: Servlet execution threw an exception root cause java.lang.OutOfMemoryError…

Accepted Answer

Your change may well be working. Does your application need a lot of memory - the stack trace shows some Image related features.

I'm guessing that the error either happens right away, with a large file, or happens later after several requests.

If the error happens right away, then you can increase memory still further, or investigate find out why so much memory is needed for one file.

If the error happens after several requests, then you could have a memory leak - where objects are not being reclaimed by the garbage collector. Using a tool like JProfiler can help you monitor how much memory is being used by your VM and can help you see what is using that memory and why objects are not being reclaimed by the garbage collector.

How to increase Java heap space for a tomcat app

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