Decide about ERRORing group when gathering

[manishtomar]

In one case CLB get node atom is consistently returning feed without any entries that is causing IndexError and group trying to converge forever. Generally get errors are transient and get resolved in subsequent cycles. But what if they are not (like this case) and keep causing the group to converge forever? How to detect such errors? After detecting such errors, I am assuming it makes sense to put the group in ERROR with proper reasons. This will require some thinking on structuring the converger since currently only step executions can cause the group to go into ERROR.