Java: New Generation Used 100%, Eden Space Used 100%, From Space Used 100%

Question

jmap -heap gives me output that says:

New Generation Used 100%, Eden Space Used 100%, From Space Used 100%, To Space Used: 0%, Perm Generation Used: 38%

Is this 100% of New, Eden, From space - a problem?

My JAVA OPTS are: -Xms10240m -Xmx14336m -XX:PermSize=192m -XX:MaxPermSize=256m -XX:NewSize=8192m -XX:MaxNewSize=8192m -XX:-DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=60

I see a lot of quick Garbage Collection. But no memory leaks using tools like JConsole

The Memory Usage can be seen here: http://tinypic.com/view.php?pic=wo213&s=6

JDK 1.6 is in use.

Answer 1

Well that is how generational collection works. You have young space (eden, from, to) and old space (tenure, perm). Young space is smaller. Once young space is full (your case) - thing called minor GC (young GC) is happening.

But minor GC should be quick. Once old space is full full GC is happening (which is more time consuming).

Idea is to have more frequent fast minor GCs and much less frequent full GCs.

You can read much more detailed explanation in this article

Answer 2

I have found the following two commands very useful

jstat -gc

or

jstat -gcutil