java.lang.OutOfMemoryError: PermGen space Exception

Question

I am getting this java.lang.OutOfMemoryError: PermGen space Exception. I am using Eclipse Juno and Tomcat 7.0. This Exception occurs at least once in every 10-1

Answer 1

What is java.lang.OutOfMemoryError: PermGen space?

Ans:

The java.lang.OutOfMemoryError: PermGen space message indicates that the Permanent Generation’s area in memory is exhausted.

Any Java applications is allowed to use a limited amount of memory. The exact amount of memory your particular application can use is specified during application startup.

Java memory is separated into different regions which can be seen in the following image:

What will be the solution for this error PermGen space?

Ans:

For Heap,

export JVM_ARGS="-Xms1024m -Xmx1024m" 

For Permgen,

JVM_ARGS="-XX:PermSize=512M -XX:MaxPermSize=512m"

You can give also additional section

-XX:MaxPermSize=512m -XX:+UseConcMarkSweepGC XX:+CMSClassUnloadingEnabled

You can also give more additional section :)

-XX:PermSize=512m -XX:MaxPermSize=512m -Djava.awt.headless=true -Dfile.encoding=UTF-8 -XX:SurvivorRatio=2 -XX:MaxTenuringThreshold=128 -XX:TargetSurvivorRatio=90 -Djava.awt.headless=true -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:+CMSIncrementalPacing -XX:CMSIncrementalDutyCycleMin=0 -XX:CMSIncrementalDutyCycle=10 -XX:+UseTLAB -XX:+CMSParallelRemarkEnabled -XX:+CMSClassUnloadingEnabled 

Metaspace: A new memory space is born

The JDK 8 HotSpot JVM is now using native memory for the representation of class metadata and is called Metaspace; similar to the Oracle JRockit and IBM JVM's.

The good news is that it means no more java.lang.OutOfMemoryError: PermGen space problems and no need for you to tune and monitor this memory space anymore.

Related Link:

1. https://plumbr.eu/outofmemoryerror/java-heap-space
2. https://plumbr.eu/outofmemoryerror/permgen-space
3. http://stas-blogspot.blogspot.in/2011/07/most-complete-list-of-xx-options-for.html#UseConcMarkSweepGC
4. https://www.javacodegeeks.com/2013/12/decoding-java-lang-outofmemoryerror-permgen-space.html
5. http://www.javavillage.in/reasons-outofmemory-permespace.php
6. Dealing with "java.lang.OutOfMemoryError: PermGen space" error

Java 8 Links

1. What is the use of MetaSpace in Java 8?
2. https://blogs.oracle.com/poonam/entry/about_g1_garbage_collector_permanent
3. https://plumbr.eu/outofmemoryerror/metaspace
4. https://dzone.com/articles/java-8-permgen-metaspace