how to get the min and max heap size settings of a JVM from within a Java program

Question

How to get the min and max heap size settings of a VM from within a Java program?

cherouvim · Accepted Answer · 2010-02-13T08:27:39.497

14

max heap size:

Runtime.getRuntime().maxMemory();

Some other calculations which you may find interesting:

Runtime runtime = Runtime.getRuntime();
long maxMemory = runtime.maxMemory();
long allocatedMemory = runtime.totalMemory();
long freeMemory = runtime.freeMemory();
long totalFreeMemory = freeMemory + (maxMemory - allocatedMemory);
long usedMemory = maxMemory - totalFreeMemory;

edited Feb 13 '10 at 08:27

answered Feb 12 '10 at 18:07

cherouvim

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I have set my max heap size as 512m. Runtime.getRuntime().maxMemory() returns 532742144 which is 508.0625 – java_geek Feb 12 '10 at 18:14
@sai praveen: yep, and if you set it to 1024m it will return something that approximates 1024m. – cherouvim Feb 12 '10 at 20:50

score 4 · Answer 2 · edited Jun 08 '20 at 07:42

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You just need to use the Runtime object with Runtime.getRuntime() and then use methods like totalMemory() and freeMemory().

edited Jun 08 '20 at 07:42

fospathi

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answered Feb 12 '10 at 18:08

metismo

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score 1 · Answer 3 · answered Feb 12 '10 at 18:09

maybe that could help you ?

http://download.oracle.com/docs/cd/E11035_01/wls100/perform/JVMTuning.html#wp1109778 http://javahowto.blogspot.com/2006/06/6-common-errors-in-setting-java-heap.html http://www.caucho.com/resin-3.0/performance/jvm-tuning.xtp http://blog.paulgu.com/2008/07/19/6-common-errors-in-setting-java-heap-size/

score 1 · Answer 4 · answered Jan 05 '11 at 12:03

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ManagementFactory.getMemoryMXBean().getHeapMemoryUsage()

answered Jan 05 '11 at 12:03

instantsetsuna

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how to get the min and max heap size settings of a JVM from within a Java program

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