Difference between PermGen Space and MetaSpace.

JavaServer Side ProgrammingProgramming

PermGen is the memory area for storing class data like static variable,byte code and etc. By default 64 Mb is allocated for PermGen. It can be tuned by using -XXMaxPermSize.

In Java 8, PermGen method area replaced with MetaSpace. They have moved permGem to the separate memory in the native OS and that is called MetaSpace. It can by default auto increases its size. In MetaSpace, classes can load and unload during the lifespan of the JVM.

Sr. No.KeyPermGenMetaSpace
1
Basic
PermGen is the memory area for storing class data like static variable,byte code and etc
In Java 8, PermGen method area replaced with MetaSpace
2
Default Memory Allocation
By default 64 Mb is allocated for PermGen
It can by default auto increases its size
3
Tuned-up Memory Flag
It can be tuned by using -XXMaxPermSize.
We can restrict upper bound of the memory by -XX:MaxMetaspaceSize
4
Memory Area
It is a special Heap space.
Since Java 8, It is now separate memory area  in the native OS
raja
Updated on 09-Sep-2020 11:29:52

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