[jboss-user] [JBoss Cache: Core Edition] - Re: How memory consumption behave?

manik.surtani@jboss.com do-not-reply at jboss.com
Wed Jun 25 05:27:52 EDT 2008

"jorgemoralespou_2" wrote : Hi,
  | My questions are:
  | 1- Why recent loaded apps have such a difference in memory?

Is this running within a JMX environment, either JBoss AS' JmxConsole or Java 5's jconsole?  If so, I'd recommend comparing the number of nodes in each cache rather than the memory used, to make sure these match up.

"jorgemoralespou_2" wrote : 
  | 2- Why memory fills so much during state transfer?

Short-lived transient objects.  State is transferred by creating NodeData objects, and streaming these.  These are then unmarshalled on the recipient, data retrieved, real nodes created, and the NodeData objects left for gc to clear up.

"jorgemoralespou_2" wrote : 
  | Another thing we have seen is that we have a region with a default cache loader of 24 hours, but we have in this region data only valid for a day, until 24:00 PM, so we have a scheduler job, that removes such a node, doing a cache.remove(FQN). When we run this job, memory lowers, but after 24 hours from start it lowers much more, so we think eviction policy is happening of internal cache data for the removed nodes. Can this be possible?

Again this could be a gc thing.  If you do a remove() on the region root so that everything in that region is removed, the node is removed from it's parent's children map such that the node is no longer accessible.  So the node - and all it's children and children's children - are still around until gc clears it all away.  I'm guessing this is what you are seeing.  Again, if you have jconsole enabled, you can watch gc cycles and I'm guessing these drops in memory usage will correspond with gc kicking in.

We have set log levels to TRACE, but we have to wait another 24 hours to see this behaviour.


View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4160473#4160473

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4160473

More information about the jboss-user mailing list