EmsAttribute's implementation DAttribute has an attribute valueHistory, that is implemented with a class that always allocates a LinkedList with a default size. We don't use that history in RHQ and it looks like the contents are never updated inside Ems anyway We should probably remove that - as in larger setups with many JMX servers with many MBeans, those valueHistory objects can pile up a large set of unused memory.
Created attachment 836338 [details] Diff to illustrate the change
Before we remove something like this from a third party library which we don't own, we'll need to talk to that project's community and owner. That attribute could be used for other things (I know MC4J uses EMS as well, it perhaps is using this attribute?)
I have forked ems into https://github.com/rhq-project/ems and applied the patch, as well as a patch to DMBean that lazily allocates the collections for attributes, operations and notifications and also removes a redundant collection of operations.
A "standard" maven build seems not enough, as ems does some magic like including the -impl jar inside the jar and also including some strange mx4j libs, where it is not clear how/if they are used at all. Running "ant install" will build the "correct" jar though.
New ems version is now in https://github.com/rhq-project/ems Pushed a pull-request at https://github.com/rhq-project/rhq/pull/20
This was merged as 5e16dabce29a28d5ac7704483711865dd02e1f85 into master
Bulk closing of RHQ 4.11 issues, now that RHQ 4.12 is out. If you find an issue with those, please open a new BZ, linking to the old one.