Investigate sub array isolation: Fault containment

Investigate sub array isolation: fault isolation and containment

This is one of the aspects of the robustness/ resilience of the TMC architecture as an NFR. 

We should be able to isolate sub arrays from faults that occurring in other subarrays. One way of testing this could be through injecting faults like random termination of processes in a sub array (Chaos Monkey for e.g. may be used) and other sub arrays should continue to run as expected. It is especially important that the Central Node should be resilient to a Sub Array node fault and not hang waiting for responses etc.