Bug 574025

Description of problem:
We are using a new JON 2.3 instance for training. There were 14 users with unique ID's logged into the system, browsing various resources and their graphing views and the system became unavailable. Attached, is the log. 

See https://enterprise.redhat.com/issue-tracker/?module=issues&action=view&tid=622613 for related case details.

Version-Release number of selected component (if applicable):
2.3.0

How reproducible:
Occurred several times when uniquely identified users simultaneously browse the resources and their graphing views.

Steps to Reproduce:
1. Start up a JON 2.3.0 instance with 15 or more platforms in inventory and monitoring data being collected for them.  Install agent on JON Server and import 'RHQ Agent' into inventory. Create 15 unique user ids.
2. Simultaneously log into the JON server, select the first available platform and i)browse trait information ii)use search to find AlertConditionQueue, FloatRangeConstraint, JBossWeb, etc. resources. iii)For first platform on the server click/view hierarchy and graphing to calculate % usage (used/total*100) for:Disk space, Memory Utilization,Processor                    
    
Actual results:
Server become unresponsive and unable to server up monitoring content.

Expected results:
No noticeable performance effect of the logged in users simultaneously browsing/view the information.

Additional info: