Description of problem:
When rebalance is started on multiple volumes and user tries to check brick advanced details it gives an "error saying could not fetch brick details. Please try again"

Version-Release number of selected component (if applicable):
rhsc-2.1.2-0.32.el6rhs.noarch

How reproducible:
Always

Steps to Reproduce:
1. Create 4-8 distribute volumes.
2. Start rebalance on all the volumes at once.
3. Now click on the brick advanced details button.

Actual results:
Brick advanced details gives an error saying "could not fetch brick details, please try again later".

Expected results:
These kind of situations need to be handled properly. For example, disallow advanced brick detail when rebalance is started across multiple volumes , as the details cannot be fetched at that time.

Additional info: