Oracle announced the general availability of Java 8 on March 18 2014. One of the features is complete removal of Permanent Generation (PermGen) space. 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 problems and no need for you to tune and monitor this memory space anymore.
In Java 8, we will still need to worry about the class metadata memory footprint. Please also keep in mind that this new feature does not magically eliminate class and classloader memory leaks. You will need to track down these problems using a different approach and by learning the new naming convention.
- Refer the article at Dzone.com for details about the PermGen successor: Metaspace.
- JDK 8 Release Notes can be found here. It covers – what’s new in JDK8, Compatibility info, known issues, troubleshooting guide etc.
- Here is another article from techempower.com, which contains a summary of the developer faced changes introduced in java 8.
- The motive for removing permanent generation is mentioned at openjdk.java.net