NFS mounted web server is not shifting when one node is down at High availlability clustering sys.

Dear ALL,
Please help me out. I have installed pcs and fence-agents-all pack in RHEL-7.1 HA node. All cluster node is running and on line in each node. I have three node. All newly created resource are available in all node. Web server is running and mounted(NFS) after debug-start command applied. Firewall nfs and http service is applied and web server can be access from in any machine with in network.. Now problem arises when node no A is down at any point of time the web service became stop and service is not mounting automatically in another on line node.

What could be the problem and how can I approach to solve it? Any probable solution is available to any one. Response will be highly appreciated.