Migrate

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Phases allowed: warm, cold.

Moves the index to the data tier that corresponds to the current phase by updating the index.routing.allocation.include._tier_preference index setting. ILM automatically injects the migrate action in the warm and cold phases. To prevent automatic migration, you can explicitly include the migrate action and set the enabled option to false.

If the cold phase defines a searchable snapshot action the migrate action will not be injected automatically in the cold phase because the managed index will be mounted directly on the target tier using the same _tier_preference infrastructure the migrate actions configures.

In the warm phase, the migrate action sets index.routing.allocation.include._tier_preference to data_warm,data_hot. This moves the index to nodes in the warm tier. If there are no nodes in the warm tier, it falls back to the hot tier.

In the cold phase, the migrate action sets index.routing.allocation.include._tier_preference to data_cold,data_warm,data_hot. This moves the index to nodes in the cold tier. If there are no nodes in the cold tier, it falls back to the warm tier, or the hot tier if there are no warm nodes available.

The migrate action is not allowed in the frozen phase. The frozen phase directly mounts the searchable snapshot using a index.routing.allocation.include._tier_preference of data_frozen,data_cold,data_warm,data_hot. This moves the index to nodes in the frozen tier. If there are no nodes in the frozen tier, it falls back to the cold tier, then the warm tier, then finally the hot tier.

The migrate action is not allowed in the hot phase. The initial index allocation is performed automatically, and can be configured manually or via index templates.

Options

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enabled
(Optional, Boolean) Controls whether ILM automatically migrates the index during this phase. Defaults to true.

Example

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In the following policy, the allocate action is specified to reduce the number of replicas before ILM migrates the index to warm nodes.

Explicitly specifying the migrate action is not required—​ILM automatically performs the migrate action unless you disable migration.

response = client.ilm.put_lifecycle(
  policy: 'my_policy',
  body: {
    policy: {
      phases: {
        warm: {
          actions: {
            migrate: {},
            allocate: {
              number_of_replicas: 1
            }
          }
        }
      }
    }
  }
)
puts response
PUT _ilm/policy/my_policy
{
  "policy": {
    "phases": {
      "warm": {
        "actions": {
          "migrate" : {
          },
          "allocate": {
            "number_of_replicas": 1
          }
        }
      }
    }
  }
}

Disable automatic migration

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The migrate action in the following policy is disabled and the allocate action assigns the index to nodes that have a rack_id of one or two.

response = client.ilm.put_lifecycle(
  policy: 'my_policy',
  body: {
    policy: {
      phases: {
        warm: {
          actions: {
            migrate: {
              enabled: false
            },
            allocate: {
              include: {
                rack_id: 'one,two'
              }
            }
          }
        }
      }
    }
  }
)
puts response
PUT _ilm/policy/my_policy
{
  "policy": {
    "phases": {
      "warm": {
        "actions": {
          "migrate" : {
           "enabled": false
          },
          "allocate": {
            "include" : {
              "rack_id": "one,two"
            }
          }
        }
      }
    }
  }
}