public final class AutoExpandReplicas
This class acts as a functional wrapper around the index.auto_expand_replicas setting.
This setting or rather it's value is expanded into a min and max value which requires special handling
based on the number of datanodes in the cluster. This class handles all the parsing and streamlines the access to these values.
public static java.util.Map<java.lang.Integer,java.util.List<java.lang.String>> getAutoExpandReplicaChanges(MetaData metaData,
Checks if the are replicas with the auto-expand feature that need to be adapted.
Returns a map of updates, which maps the indices to be updated to the desired number of replicas.
The map has the desired number of replicas as key and the indices to update as value, as this allows the result
of this method to be directly applied to RoutingTable.Builder#updateNumberOfReplicas.