Description of problem:

Webadmin UI sometimes became noticeably sluggish, and janky after continued usage, sometimes giving re-occuring UI general exceptions making it necessary to close the browser a few times to improve experience.  This occurred after performing multiple domain operations and checking the events tab, and browsing several VMs (each vm containing 5 disks) over time and continued usage without closing the browser.

Dataset: 
DC 1
200 VMs, 1000 disks, 2 hosts, 4 domains

Browser: Firefox 49

Firefox memory was around 625mb sometimes up to 1GB on client side

Items to note:
   Orphan Nodes around 288mb 
   Re-occurring error message in UI (Uncaught Exception)
   Dataset was 1000 Disks, 200 VMs [5 disks per VM]
   Browsing activities centered around performing common ISCSI domain management tasks over several hours and browsing disk details of VMs, start/stopping VMs.
   

Version-Release number of selected component (if applicable):
Testing performed on 4.0.5.1

How reproducible:
Requires effort to reproduce, additionally requires dataset of 1k disks, and 100 of 200 VMs 'up' state and continued browsing/usage.

Steps to Reproduce:
1. Create/Activate Storage Domains
2. Trigger long running tasks that result in many status changes like starting 5 Vms every 2-3 minutes.
3. Browse multiple VMs and respective 'disk' pane on the bottom panel.


Actual results:
Should begin to notice sluggish user experience when opening, scrolling, typing in dialog boxes of Webadmin; especially when browsing VM results and scrolling.
Sometimes browser appears temporarily unresponsive along with high client CPU usage.

Expected results:
Better user experience without locking, or sluggishness

Additional info:
When the browser did become unresponsive or sluggish generally firefox would show high CPU usage, though its unclear if this is a cause or response.

Logs, Errors found: https://drive.google.com/open?id=0B8V1DXeGhPPWbGdCaU5JQmQ3U0E