[news.eclipse.technology.memory-analyzer] Re: Eden v Old

[andreas.buchen@xxxxxxx (Andreas Buchen)]

Hi Michael,

sorry, bad news, the heap dump neither contains the info about the space 
the object is in (also not if the String is in perm) nor an object copy 
count. With a heap dump only you will have problems to figure this out.

Maybe take a look at the number of weak and soft references. Many of those 
references increase the stop-the-world time, because the VM has to decide 
at one point or another whether to mark the objects "behind" the refrence 
or not. From what I understand, this has to be done in sync with all gc 
threads.

In the OQL pane, you could run "SELECT * FROM INSTANCEOF 
java.lang.Reference" to see all those references currently in the heap. 
Also the "Java Basics" -> Reference statistics queries can give you an 
overview of what those references currently keep alive.

The other point to look into are finalizers. As you probably, finalizers 
always require 2 full gc to actually free up the space. Again, the "Java 
Basics" category also contains a query which displays finalizers and 
what's in the queue.



Hopefully I could give you some hints,


Andreas.