== Indices mix index allocation filters with data tiers node roles to move through data tiers
Elasticsearch standardized the implementation of https://www.elastic.co/blog/elasticsearch-data-lifecycle-management-with-data-tiers[hot-warm-cold architectures]
to <<data-tiers, data tiers>> in version 7.10.
Some indices and deployments might have not fully transitioned to <<data-tiers, data tiers>>
and mix the new way of implementing the hot-warm-cold architecture with
<<shard-allocation-filtering, legacy>> based node attributes.
This could lead to unassigned shards or shards not transitioning to the desired
