Increase java heap size

When you install this way, these settings are kept in the Windows Registry.
If you have the start menu items, the easiest way to change them is to go to
Start -> Programs -> Apache Tomcat -> Tomcat Configuration -> Java (tab).
There are fields for your initial and max heap sizes.

First Calculate the number of threads you can create

(MaxProcessMemory – JVMMemory – ReservedOsMemory) / (ThreadStackSize) = Number of threads


For Java 1.5 you will get the following results assuming that the OS reserves about 120MB:

1.5GB allocated to JVM: (2GB-1.5Gb-120MB)/(1MB) = ~380 threads

1.0GB allocated to JVM: (2GB-1.0Gb-120MB)/(1MB) = ~880 threads

Your Java Options Example:

-Xms 512m
-Xmx 1024m


Append following line in catalina.bat in front of JAVA_OPTS
-Xms1024m -Xmx1024m -XX:MaxPermSize=128m

set JAVA_OPTS=%JAVA_OPTS% -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.util.logging.config.file=”%CATALINA_BASE%\conf\” -Xms1024m -Xmx1024m -XX:MaxPermSize=128m

About ashokabhat

I am a C,C ,JAVA,Adobe Flex,.NET Programmer Currently working as a Software Developer
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