Shrink

Phases allowed: warm

Sets an index to read-only and shrinks it into a new index with fewer primary shards. The name of the new index is of the form shrink-<original-index-name>. For example, if the name of the source index is logs, the name of the shrunken index is shrink-logs.

The shrink action allocates all primary shards of the index to one node so it can call the Shrink API to shrink the index. After shrinking, it swaps aliases that point to the original index to the new shrunken index.

If the shrink action is used on a follower index, policy execution waits until the leader index rolls over (or is otherwise marked complete), then converts the follower index into a regular index with the the Unfollow action before performing the shrink operation.

Shrink options

number_of_shards
(Required, integer) Number of shards to shrink to. Must be a factor of the number of shards in the source index.

Example

PUT _ilm/policy/my_policy
{
  "policy": {
    "phases": {
      "warm": {
        "actions": {
          "shrink" : {
            "number_of_shards": 1
          }
        }
      }
    }
  }
}