How to Clear Permgen Space Error in Tomcat

How to clear PermGen space Error in tomcat

The PermGen space is what Tomcat uses to store class definitions (definitions only, no instantiations) and string pools that have been interned. From experience, the PermGen space issues tend to happen frequently in dev environments really since Tomcat has to load new classes every time it deploys a WAR or does a jspc (when you edit a jsp file). Personally, I tend to deploy and redeploy wars a lot when I’m in dev testing so I know I’m bound to run out sooner or later (primarily because Java’s GC cycles are still kinda crap so if you redeploy your wars quickly and frequently enough, the space fills up faster than they can manage).

This should theoretically be less of an issue in production environments since you (hopefully) don’t change the codebase on a 10 minute basis. If it still occurs, that just means your codebase (and corresponding library dependencies) are too large for the default memory allocation and you’ll just need to mess around with stack and heap allocation. I think the standards are stuff like:

-XX:MaxPermSize=SIZE

I’ve found however the best way to take care of that for good is to allow classes to be unloaded so your PermGen never runs out:

-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled

Stuff like that worked magic for me in the past. One thing tho, there’s a significant performance tradeoff in using those, since permgen sweeps will make like an extra 2 requests for every request you make or something along those lines. You’ll need to balance your use with the tradeoffs.

Tomcat: OutOfMemoryError Permgen Space

One way is to increase your permgen space by adding the following JVM arguments to below

-XX:MaxPermSize=256m

But it will only delay the OOM error. If you do redeployment again and again, you will run into the permgen out of memory again. The reason is explained very clearly in this article, which I won't repeat here. http://frankkieviet.blogspot.com/2006/10/classloader-leaks-dreaded-permgen-space.html. Sorry I do not have a different way to setup the logger differently to avoid this issue. In practice, I always increase the MaxPermSize and then cycle server before deployment.

Dealing with java.lang.OutOfMemoryError: PermGen space error

The solution was to add these flags to JVM command line when Tomcat is started:

-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled

You can do that by shutting down the tomcat service, then going into the Tomcat/bin directory and running tomcat6w.exe. Under the "Java" tab, add the arguments to the "Java Options" box. Click "OK" and then restart the service.

If you get an error the specified service does not exist as an installed service you should run:

tomcat6w //ES//servicename

where servicename is the name of the server as viewed in services.msc

Source: orx's comment on Eric's Agile Answers.

PermGen space error while application is running

Each webapp in Tomcat has a separate class loader with a separate set of loaded classes. When we start Tomcat it does not load all classes of all its apps at once but rather it loads the apps lazily. When an app becomes active it starts loading its classes and it may happen that JVM runs out permgen space. That is, it may happen even without redeploying apps.

Tomcat - PermGen space Exception

The PermGen space is what Tomcat uses to store class definitions (definitions only, no instantiations) and string pools that have been interned. From experience, the PermGen space issues tend to happen frequently in dev environments really since Tomcat has to load new classes every time it deploys a WAR or does a jspc (when you edit a jsp file). Personally, I tend to deploy and redeploy wars a lot when I’m in dev testing so I know I’m bound to run out sooner or later (primarily because Java’s GC cycles are still kinda crap so if you redeploy your wars quickly and frequently enough, the space fills up faster than they can manage).

This should theoretically be less of an issue in production environments since you (hopefully) don’t change the codebase on a 10 minute basis. If it still occurs, that just means your codebase (and corresponding library dependencies) are too large for the default memory allocation and you’ll just need to mess around with stack and heap allocation. I think the standards are stuff like:

-XX:MaxPermSize=SIZE
I’ve found however the best way to take care of that for good is to allow classes to be unloaded so your PermGen never runs out:

-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled
Stuff like that worked magic for me in the past. One thing tho, there’s a significant performance tradeoff in using those, since permgen sweeps will make like an extra 2 requests for every request you make or something along those lines. You’ll need to balance your use with the tradeoffs.

java.lang.OutOfMemoryError: PermGen space in tomcat with eclipse

try to raise perm space, add following parameters to vm start-up

-XX:PermSize=256m -XX:MaxPermSize=256m

also add -XX:MaxPermSize=256m to Tomcat in Eclipse: Server > Open Launch Configuration > Arguments

Update (in 2014): take a look here at this question and answer about the new Java 8 Metaspace.

and take a look here:

How to deal with “java.lang.OutOfMemoryError: PermGen space” error

java.lang.OutOfMemoryError: PermGen space

If you're using Tomcat as a Server of Eclipse, go to Server view, then double click on Tomcat, then "Open Launch Configuration", go to Arguments tab, and after setting -Dcatalina.base="" put this

-Xms256m -Xmx512m -XX:MaxPermSize=512m -XX:PermSize=128m

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