2.7.1 api-rest pod hung after 1 node is rebooted

[veenadong]

Detailed description:

#1715 (comment)

To Reproduce
After a node is rebooted, repeatedly call "kubectl mayastor get volumes", after a few minutes the pod hangs.
The pod becomes unresponsive, ie. not able to "exec" into the pod.
If already "exec" into the pod, commands such as "ps", "top" will not respond.