How to change the HEAP memory in the middle of computation

[Paul K.]

Hi! I ant to know if there is a way to reallocate the RAM memory for a
java application that is already running, Iknow that in order to set it
initially is like:


java -ms32m -mx128m MyClassName

but what if in the middle of the execution i need to get more memory
lets say up to 1G?

regards

paul.

 

[mearvk]

Hi! I ant to know if there is a way to reallocate the RAM memory for a
java application that is already running, Iknow that in order to set it
initially is like:


java -ms32m -mx128m MyClassName

but what if in the middle of the execution i need to get more memory
lets say up to 1G?

regards

paul.

There are 3 flags you should use. I believe these flags will solve your
problem:

-Xmn 256M -Xms 512M -Xmx 1024M

-Xmn is your minimum.
-Xms is your initial.
-Xmx is your maximum.

This allows the JVM a lot of room and should address your concerns.

Mearvk

 

[Daniel Pitts]

Hi! I ant to know if there is a way to reallocate the RAM memory for a
java application that is already running, Iknow that in order to set it
initially is like:


java -ms32m -mx128m MyClassName

but what if in the middle of the execution i need to get more memory
lets say up to 1G?

regards

paul.

The JVM will allocated an initial amount... When there isn't enough
heap at any given time, it will increase the heap size up to the stated
maximum. You should set the maximum to 1024m if you want to allow it
to go up to 1G.

HTH
- Daniel.

 

[Timothy Bendfelt]

There are 3 flags you should use. I believe these flags will solve your
problem:

-Xmn 256M -Xms 512M -Xmx 1024M

-Xmn is your minimum.
-Xms is your initial.
-Xmx is your maximum.

-Xmn specifies the young generation size. It informs the ratio hotspot
uses between old and new generation spaces. It should never be set to
larger that 1/2 the total heap size (unless the parallel collector is in
use -XX:+UseParallelGC)