Index Shard Allocation

This module provides per-index settings to control the allocation of shards to nodes:

Shard allocation filtering: Controlling which shards are allocated to which nodes.
Delayed allocation: Delaying allocation of unassigned shards caused by a node leaving.
Total shards per node: A hard limit on the number of shards from the same index per node.
Data tier allocation: Controls the allocation of indices to data tiers.