Report node "roles" in the /_cluster/allocation/explain response.
Nodes with limited sets of roles may affect shard distribution in ways
users did not originally consider, so it is helpful to surface this
information along with node allocation decision explanations.
The `shards_availability` indicator diagnoses the condition where
indices need to be restored from snapshot.
Starting with 8.0 using feature_states when restoring from snapshot is
mandatory.
This adds support for the `FEATURE_STATE` affected resource to aid with
building up the snapshot restore API call (which will need to include
all the indices and feature states reported by the restore-from-snapshot
diagnosis).
Note that the health API will not report any indices that are part of a
feature state.
This adds troubleshooting documentation for the case when the ShardsAvailabilityHealthIndicatorService
reports that there are not enough nodes in the data tier (user action "increase_node_capacity_for_allocations" or
"increase_tier_capacity_for_allocations_". This covers both the cloud and self-managed environments. For
cloud we first recommend increasing the number of availability zones (because you cannot directly add nodes), and
decreasing index.number_of_replicas if that is not possible. For self-managed, we first recommend adding nodes,
and decreasing index.number_of_replicas if that is not possible.
This adds a troubleshooting doc for indices that mix index filtering allocation
with data tiers routing.
Co-authored-by: Lee Hinman <dakrone@users.noreply.github.com>
