Explain lifecycle APIedit

Shows an index’s current lifecycle status.

Requestedit

GET <index>/_ilm/explain

Descriptionedit

Retrieves information about the index’s current lifecycle state, such as the currently executing phase, action, and step. Shows when the index entered each one, the definition of the running phase, and information about any failures.

Path Parametersedit

index (required)
(string) Identifier for the index.

Request Parametersedit

timeout
(time units) Specifies the period of time to wait for a response. If no response is received before the timeout expires, the request fails and returns an error. Defaults to 30s. For more information about time units, see Time unitsedit.
master_timeout
(time units) Specifies the period of time to wait for a connection to the master node. If no response is received before the timeout expires, the request fails and returns an error. Defaults to 30s. For more information about time units, see Time unitsedit.

Authorizationedit

You must have the view_index_metadata or manage_ilm or both privileges on the indices being managed to use this API. For more information, see Security Privileges.

Examplesedit

The following example retrieves the lifecycle state of my_index:

GET my_index/_ilm/explain

When management of the index is first taken over by ILM, explain shows that the index is managed and in the new phase:

{
  "indices": {
    "my_index": {
      "index": "my_index",
      "managed": true, 
      "policy": "my_policy", 
      "lifecycle_date_millis": 1538475653281, 
      "phase": "new",
      "phase_time_millis": 1538475653317, 
      "action": "complete",
      "action_time_millis": 1538475653317, 
      "step": "complete",
      "step_time_millis": 1538475653317 
    }
  }
}

Shows if the index is being managed by ILM. If the index is not managed by ILM the other fields will not be shown

The name of the policy which ILM is using for this index

The timestamp used for the min_age

When the index entered the current phase

When the index entered the current action

When the index entered the current step

Once the policy is running on the index, the response includes a phase_execution object that shows the definition of the current phase. Changes to the underlying policy will not affect this index until the current phase completes.

{
  "indices": {
    "test-000069": {
      "index": "test-000069",
      "managed": true,
      "policy": "my_lifecycle3",
      "lifecycle_date_millis": 1538475653281,
      "lifecycle_date": "2018-10-15T13:45:21.981Z",
      "phase": "hot",
      "phase_time_millis": 1538475653317,
      "phase_time": "2018-10-15T13:45:22.577Z",
      "action": "rollover",
      "action_time_millis": 1538475653317,
      "action_time": "2018-10-15T13:45:22.577Z",
      "step": "attempt-rollover",
      "step_time_millis": 1538475653317,
      "step_time": "2018-10-15T13:45:22.577Z",
      "phase_execution": {
        "policy": "my_lifecycle3",
        "phase_definition": { 
          "min_age": "0ms",
          "actions": {
            "rollover": {
              "max_age": "30s"
            }
          }
        },
        "version": 3, 
        "modified_date": "2018-10-15T13:21:41.576Z", 
        "modified_date_in_millis": 1539609701576 
      }
    }
  }
}

The JSON phase definition loaded from the specified policy when the index entered this phase

The version of the policy that was loaded

The date the loaded policy was last modified

The epoch time when the loaded policy was last modified

If ILM is waiting for a step to complete, the response includes status information for the step that’s being performed on the index.

{
  "indices": {
    "test-000020": {
      "index": "test-000020",
      "managed": true,
      "policy": "my_lifecycle3",
      "lifecycle_date_millis": 1538475653281,
      "lifecycle_date": "2018-10-15T13:45:21.981Z",
      "phase": "warm",
      "phase_time_millis": 1538475653317,
      "phase_time": "2018-10-15T13:45:22.577Z",
      "action": "allocate",
      "action_time_millis": 1538475653317,
      "action_time": "2018-10-15T13:45:22.577Z",
      "step": "check-allocation",
      "step_time_millis": 1538475653317,
      "step_time": "2018-10-15T13:45:22.577Z",
      "step_info": { 
        "message": "Waiting for all shard copies to be active",
        "shards_left_to_allocate": -1,
        "all_shards_active": false,
        "actual_replicas": 2
      },
      "phase_execution": {
        "policy": "my_lifecycle3",
        "phase_definition": {
          "min_age": "0ms",
          "actions": {
            "allocate": {
              "number_of_replicas": 2,
              "include": {
                "box_type": "warm"
              },
              "exclude": {},
              "require": {}
            },
            "forcemerge": {
              "max_num_segments": 1
            }
          }
        },
        "version": 2,
        "modified_date": "2018-10-15T13:20:02.489Z",
        "modified_date_in_millis": 1539609602489
      }
    }
  }
}

Status of the step that’s in progress.

If the index is in the ERROR step, something went wrong while executing a step in the policy and and you will need to take action for the index to proceed to the next step. To help you diagnose the problem, the explain response shows the step that failed and the step info provides information about the error.

{
  "indices": {
    "test-000056": {
      "index": "test-000056",
      "managed": true,
      "policy": "my_lifecycle3",
      "lifecycle_date_millis": 1538475653281,
      "lifecycle_date": "2018-10-15T13:45:21.981Z",
      "phase": "hot",
      "phase_time_millis": 1538475653317,
      "phase_time": "2018-10-15T13:45:22.577Z",
      "action": "rollover",
      "action_time_millis": 1538475653317,
      "action_time": "2018-10-15T13:45:22.577Z",
      "step": "ERROR",
      "step_time_millis": 1538475653317,
      "step_time": "2018-10-15T13:45:22.577Z",
      "failed_step": "attempt-rollover", 
      "step_info": { 
        "type": "resource_already_exists_exception",
        "reason": "index [test-000057/H7lF9n36Rzqa-KfKcnGQMg] already exists",
        "index_uuid": "H7lF9n36Rzqa-KfKcnGQMg",
        "index": "test-000057"
      },
      "phase_execution": {
        "policy": "my_lifecycle3",
        "phase_definition": {
          "min_age": "0ms",
          "actions": {
            "rollover": {
              "max_age": "30s"
            }
          }
        },
        "version": 3,
        "modified_date": "2018-10-15T13:21:41.576Z",
        "modified_date_in_millis": 1539609701576
      }
    }
  }
}

The step that caused the error

What went wrong