[role="xpack"]
[[ilm-actions]]
== Index lifecycle actions

<<ilm-allocate,Allocate>>::
Move shards to nodes with different performance characteristics
and reduce the number of replicas.

<<ilm-delete,Delete>>::
Permanently remove the index.

<<ilm-forcemerge,Force merge>>::
Reduce the number of index segments and purge deleted documents.

<<ilm-migrate,Migrate>>::
Move the index shards to the <<data-tiers, data tier>> that corresponds
to the current {ilm-init} phase.

<<ilm-readonly,Read only>>::
Block write operations to the index.

<<ilm-rollover,Rollover>>::
Remove the index as the write index for the rollover alias and
start indexing to a new index.

<<ilm-downsample,Downsample>>::
Aggregates an index's time series data and stores the results in a new read-only
index. For example, you can downsample hourly data into daily or weekly summaries.

<<ilm-searchable-snapshot, Searchable snapshot>>::
Take a snapshot of the managed index in the configured repository
and mount it as a searchable snapshot.

<<ilm-set-priority,Set priority>>::
Lower the priority of an index as it moves through the lifecycle
to ensure that hot indices are recovered first.

<<ilm-shrink,Shrink>>::
Reduce the number of primary shards by shrinking the index into a new index.

<<ilm-unfollow,Unfollow>>::
Convert a follower index to a regular index.
Performed automatically before a rollover, shrink, or searchable snapshot action.

<<ilm-wait-for-snapshot,Wait for snapshot>>::
Ensure that a snapshot exists before deleting the index.

include::actions/ilm-allocate.asciidoc[]
include::actions/ilm-delete.asciidoc[]
include::actions/ilm-forcemerge.asciidoc[]
include::actions/ilm-migrate.asciidoc[]
include::actions/ilm-readonly.asciidoc[]
include::actions/ilm-rollover.asciidoc[]
include::actions/ilm-downsample.asciidoc[]
include::actions/ilm-searchable-snapshot.asciidoc[]
include::actions/ilm-set-priority.asciidoc[]
include::actions/ilm-shrink.asciidoc[]
include::actions/ilm-unfollow.asciidoc[]
include::actions/ilm-wait-for-snapshot.asciidoc[]