Make Pod Disruption Budgets Configurable

[Prabhaker24]

Description

Current Pravega poddisruption budgets prevent segmentstore and controller pods from evicting if number of segmentstore or controller are greater than number of nodes.

Cannot evict pod as it would violate the pod's disruption budget.\nerror when evicting pod \"nautilus-pravega-segment-store-5\" (will retry after 5s): Cannot evict pod as it would violate the pod's disruption budget.\

Cannot evict pod as it would violate the pod's disruption budget.\nerror when evicting pod \"nautilus-bookie-3\" (will retry after 5s): Cannot evict pod as it would violate the pod's disruption budget

Importance

nice_to_have

Location

controller.go and segmentstore.go files

Suggestions for an improvement

Make the PDB configurable i.e allow updation of maxUnavailable for both controller and segment store