increase java heap size

[Michael Zellmann]

I know this has been asked before, and I have tried to read the answers and implement their suggestions, but I have not succeeded yet. I have Tomcat 5.5 running as a Windows Service. I am running Windows XP SP2, with 2GB or real memory. The Tomcat service is started automatically at system start-up, not from a Start menu. I need to increase the heap size. I have tried setting CATALINA_OPTS in the system environment variables. It is now CATALINA_OPTS=-Xms64m -Xmx256m However, when I look at Tomcat status, I see Free memory: 17.16 MB Total memory: 63.56 MB Max memory: 63.56 MB.

How can I increase the heap size?

[Ben Souther]

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.

[Ben Souther]

[Michael Zellmann]

Thanks !

[sameh gad]

First Calculate the number of threads you can create

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

Example:

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
-Xss256k
-XX:MaxPermSize=256m
-XX:ReservedCodeCacheSize=128m

For More Details i Found this link
http://www.reviewservers.com/index.php?page/tomcat

we wish this may help you

[Billy Tsai]

Hi
if I wish to increase the maximum memory setting without using the Tomcat coniguration window(non windows environment) but modify the catalina.bat(or catalina.sh)
do I just add a line CATALINA_OPTS='-Xmx512m' in catlina.bat(.sh) or startup.bat(startup.sh) ?

or is it JAVA_OPTS=CATALINA_OPTS='-Xmx512m'

thanks

[Ben Souther]

The bat files are for Windows and the sh files are for unix.
And it's JAVA_OPTS.

[Billy Tsai]

so do I add JAVA_OPTS='-Xmx512m' to catalina.sh or startup.sh?

[Arvind Mishra]

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

It should look like.

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

there is another solution.
add a new environment variable called JAVA_OPTS with value

    -Xms1024m -Xmx1024m -XX:MaxPermSize=128m

[Anubhav Anand]

The maximum memory for JVM on windows machine is limited to 1.6 Gigs.
Sometimes, you do need more than that. But, can't do.

[iNimish Nimish]

[quote=Anubhav Anand]The maximum memory for JVM on windows machine is limited to 1.6 Gigs.
Sometimes, you do need more than that. But, can't do.[/quote]

I do not have catalina.bat in my bin folder ... should i be setting this in the environment variables?

[Bruno Kinoshita]

Hey guys,

I am using Tomcat 6.0.24 as Windows Service. There is no startup.bat.

Googling I stumbled with this blog post:

http://blog.scottpenrose.com/2009/01/29/modify-windows-tomcat-service-heap-size/

Here it says to execute "tomcat6 //US//Tomcat6 –JvmMs XXX –jvmMx YYY" in tomcat/bin folder.

I executed tomcat6 //US//Tomcat6 –-JvmMs=512 –-jvmMx=1024 and it is working now. I hope it helps somebody
(ref: http://tomcat.apache.org/tomcat-5.5-doc/windows-service-howto.html)

Cheers,
Bruno