Garbage
collector is a module that removes un used variables and un referenced objects
from the memory.
There are 2 ways to call Garbage collector forcefully.
2) New objects are created into young generation and subsequently moved to old generation.
3) String pool is created in Perm area of Heap, garbage collection can occur in perm space but depends upon JVM to JVM.
4) Minor garbage collection is used to move object from Eden space to Survivor 1 and Survivor 2 space and Major collection is used to move object from young to tenured generation.
5) Whenever Major garbage collection occurs application threads stops during that period which will reduce application's performance and throughput.
6) There are few performance improvement has been applied in garbage collection in java 6 and we usually use JRE 1.6.20 for running our application.
7) JVM command line options -Xmx and -Xms is used to setup starting and max size for Java Heap. Ideal ratio of this parameter is either 1:1 or 1:1.5 based upon my experience for example you can have either both -Xmx and -Xms as 1GB or -Xms 1.2 GB and 1.8 GB.
8) There is no manual way of doing garbage collection in Java.
There are 2 ways to call Garbage collector forcefully.
a. System.gc()
b. Runtime.getRuntime().gc()
1) Java Heap is divided into three generation
for sake of garbage collection. These are young generation, tenured or old
generation and Perm area.
2) New objects are created into young generation and subsequently moved to old generation.
3) String pool is created in Perm area of Heap, garbage collection can occur in perm space but depends upon JVM to JVM.
4) Minor garbage collection is used to move object from Eden space to Survivor 1 and Survivor 2 space and Major collection is used to move object from young to tenured generation.
5) Whenever Major garbage collection occurs application threads stops during that period which will reduce application's performance and throughput.
6) There are few performance improvement has been applied in garbage collection in java 6 and we usually use JRE 1.6.20 for running our application.
7) JVM command line options -Xmx and -Xms is used to setup starting and max size for Java Heap. Ideal ratio of this parameter is either 1:1 or 1:1.5 based upon my experience for example you can have either both -Xmx and -Xms as 1GB or -Xms 1.2 GB and 1.8 GB.
8) There is no manual way of doing garbage collection in Java.
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