How to force cache to release objects

Question

In MappingWorkbench I have configured the cache for my class (SoftCacheWeakIdentityMap, size 30000). Then I use following code to write out the cache size (more precisely: number of objects in the cache) and the cache size is bigger then 30000. Why is there more objects than 30000 (even if no users are connected)? How can I force Toplink (or JVM) to release not used objects?
Thank you in advance for your answer.
Jan Kostrhun
ServerSession sess = (ServerSession) SessionManager.getManager().getSession (args[0]);
RuntimeServices rts = new RuntimeServices (sess);
List seznam = rts.getClassesInSession();
Collections.sort (seznam);
Iterator iter = seznam.iterator();
while (iter.hasNext()) {
String nazev = (String) iter.next();
try {
int pocet = rts.getNumberOfObjectsInIdentityMap (nazev).intValue();
out.println (nazev + " : " + pocet);
} catch (ClassNotFoundException cnfe) {
out.println ("Nenalezena trida: " + nazev);

Answer 1

You can adjust the tombstone lifetime down to a minimum of 2 days.  The garbage collection interval can be reduced from the default of 12 hours to a minimum of 1 hour.  You an also force the garbage collection to run manually, as described here:
http://blogs.technet.com/b/ad/archive/2009/03/24/taking-out-the-trash.aspx
Remember that if you have the AD Recycle Bin turned on you will need also consider the msDS-deletedObjectLifetime.  More info on this here:
http://blogs.technet.com/b/askds/archive/2009/08/27/the-ad-recycle-bin-understanding-implementing-best-practices-and-troubleshooting.aspx
The bottom line is that you cannot purge deleted objects from the DIT on demand. You have to wait for at least the tombstone lifetime to expire, and potentially the msDS-deletedObjectLifetime too.
Tony www.activedir.org Blog: www.open-a-socket.com
Good Summary. Just want to add:
The Garbage Collector process can be initiated manually by triggering the
operational attribute: “doGarbageCollection”: at any time http://msdn.microsoft.com/en-us/library/cc223317(v=prot.10)
Enfo Zipper
Christoffer Andersson – Principal Advisor
http://blogs.chrisse.se - Directory Services Blog