Monday, May 27, 2013

Setting JVM Heap size at runtime

To set the JVM heap size, compile the program normally.
For example, consider Runtime.java program.
Compilation: javac Runtime.java
Now, to set minimum heap size(let, 16 MB) required by JVM, run the program as follows :
java -Xms16m Runtime 
We can also restrict maximum size(let 512 MB) utilized by JVM:
java -Xmx512m Runtime
 Both these options can also be combined to specify upper and lower bounds of JVM heap size:
java -Xms16m -Xmx512m Runtime
Now you can run a program that requires huge computational space.