CODEWITHSUNDEEP
javagarbage-collection
Zéychin
Zéychin

Reputation: 4205

Find Out What Objects Garbage Collector Is Releasing:

I am trying to find memory leaks in a program I did not design (I'm new to the project). As it is quite a large program, I am having some trouble. I have tried a few profilers, and most of them hang or crash when attempting to follow the allocation stack trace to see which objects are taking up all of the memory.

I am running System.gc(); in a Thread and attempting to find out what exactly it is releasing/freeing. From the profiler, I can see that it is releasing, but I need to know what it is releasing.

Is there some way to get information at runtime from the garbage collector as to which objects it is releasing/freeing?

If not, or if this is a bad way to even think about trying to approach this, any other suggestions would be appreciated.

Upvotes: 0

Views: 129

Answers (3)

Riddhish.Chaudhari
Riddhish.Chaudhari

Reputation: 853

i don't have the exact solution of which object will be realized by System.gc();

but JAVA provides built in GUI tool facility to JAVA monitoring and Management Console

you found jconsole in java/bin folder to run it: use command

cd $JAVA_HOME/bin
./jconsole

Upvotes: 0

Peter Lawrey
Peter Lawrey

Reputation: 533492

I would use a memory profiler to find a memory leak. You can start with VisualVM. this may find your problem, but if it doesn't try an evaluation version of a commercial profiler like YourKit.

These tools can not only tell you what is being discarded but where it is being creating in the first place. It has a graphical interface so you can see the biggest or most numerous.

Upvotes: 1

Bruno Grieder
Bruno Grieder

Reputation: 29814

My preferred way of finding memory leaks is triggering a heap dump by either waiting for it to happen (following an OOM) using -XX:+HeapDumpOnOutOfMemoryError as a JVM launch parameter or 'on demand' using jsconsole/jmap.

Then run (the usually large) dump file through the excellent MAT http://www.eclipse.org/mat/

Upvotes: 2

Related Questions