The setenv.sh file contains the minimum and maximum heap size for each application server. The setenv.sh file should be located at $tomcat_home/bin/setenv.sh. The -Xss option is used to specify the minimum heap size and the -Xmx option is used to specify the maximum heap size. In this example, the minimum heap size is 256 KB and the maximum heap size is 128 MB.
If you change the minimum or maximum heap size, you will need to restart the application server for the change to take effect.