Index lifecycle actions [ilm-actions]

:::{note} This section provides detailed reference information for Index lifecycle actions.

Refer to Index lifecycle management in the Manage data section for overview, getting started and conceptual information. :::

Allocate : Move shards to nodes with different performance characteristics and reduce the number of replicas.

Delete : Permanently remove the index.

Force merge : Reduce the number of index segments and purge deleted documents.

Migrate : Move the index shards to the data tier that corresponds to the current {{ilm-init}} phase.

Read only : Block write operations to the index.

Rollover : Remove the index as the write index for the rollover alias and start indexing to a new index.

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.

Searchable snapshot : Take a snapshot of the managed index in the configured repository and mount it as a searchable snapshot.

Set priority : Lower the priority of an index as it moves through the lifecycle to ensure that hot indices are recovered first.

Shrink : Reduce the number of primary shards by shrinking the index into a new index.

Unfollow : Convert a follower index to a regular index. Performed automatically before a rollover, shrink, or searchable snapshot action.

Wait for snapshot : Ensure that a snapshot exists before deleting the index.