Blocker Description
Currently it is very confusing to have the two configs in two different files (yarn-site.xml and capacity-scheduler.xml).
Maybe a better approach is: we can delete the scheduling-request.allowed in CS, and update placement-constraints configs in yarn-site.xml a bit:
- Remove placement-constraints.enabled, and add a new placement-constraints.handler, by default is none, and other acceptable values are a. external-processor (since algorithm is too generic to me), b. scheduler.
- And add a new PlacementProcessor just to pass SchedulingRequest to scheduler without any modifications.