This is a Rebalancer specific to semi-automatic mode. It is tasked with computing the ideal
state of a resource based on a predefined preference list of instances willing to accept
The input is the optional current assignment of partitions to instances, as well as the required
existing instance preferences.
The output is a mapping based on that preference list, i.e. partition p has a replica on node k
with state s.
Given an ideal state for a resource and the liveness of instances, compute the best possible
state assignment for each partition's replicas.
||Provides the current state and pending state transitions for all partitions
This method provides all the relevant information needed to rebalance a resource.
If you need additional information use manager.getAccessor to read the cluster data.
This allows one to compute the newIdealState according to app specific requirement.
||Name of the resource to be rebalanced
||Provides the current state and pending state transition for all
||Provides additional methods to retrieve cluster data.