elasticsearch/docs/reference/indices/get-data-stream.asciidoc

[[indices-get-data-stream]]
=== Get data stream API
++++
<titleabbrev>Get data stream</titleabbrev>
++++

Retrieves information about one or more <<data-streams,data streams>>.
See <<get-info-about-a-data-stream>>.

////
[source,console]
----
PUT /_ilm/policy/my-lifecycle-policy
{
  "policy": {
    "phases": {
      "hot": {
        "actions": {
          "rollover": {
            "max_size": "25GB"
          }
        }
      },
      "delete": {
        "min_age": "30d",
        "actions": {
          "delete": {}
        }
      }
    }
  }
}

PUT /_index_template/my-index-template
{
  "index_patterns": [ "my-data-stream*" ],
  "data_stream": {
    "timestamp_field": "@timestamp"
  },
  "template": {
    "mappings": {
      "properties": {
        "@timestamp": {
          "type": "date"
        }
      }
    },
    "settings": {
      "index.lifecycle.name": "my-lifecycle-policy"
    }
  }
}

PUT /_data_stream/my-data-stream

POST /my-data-stream/_rollover

PUT /_data_stream/my-data-stream_two
----
// TESTSETUP
////

////
[source,console]
----
DELETE /_data_stream/*
DELETE /_index_template/*
DELETE /_ilm/policy/my-lifecycle-policy
----
// TEARDOWN
////

[source,console]
----
GET /_data_stream/my-data-stream
----

[[get-data-stream-api-request]]
==== {api-request-title}

`GET /_data_stream/<data-stream>`

[[get-data-stream-api-path-params]]
==== {api-path-parms-title}

`<data-stream>`::
(Required, string)
Name of the data stream to retrieve.
Wildcard (`*`) expressions are supported.

[role="child_attributes"]
[[get-data-stream-api-response-body]]
==== {api-response-body-title}

`data_streams`::
(array of objects)
Contains information about retrieved data streams.
+
.Properties of objects in `data_streams`
[%collapsible%open]
====
`name`::
(string)
Name of the data stream.

`timestamp_field`::
(object)
Contains information about the data stream's timestamp field.
+
.Properties of `timestamp_field`
[%collapsible%open]
=====
`name`::
(string)
Name of the data stream's timestamp field. This field must be included in every
document indexed to the data stream.

`mapping`::
(<<mapping,field mapping object>>)
Field mapping for the data stream's timestamp field.
=====

`indices`::
(array of objects)
Array of objects containing information about the data stream's backing
indices.
+
The last item in this array contains information about the stream's current
<<data-stream-write-index,write index>>.
+
.Properties of `indices` objects
[%collapsible%open]
=====
`index_name`::
(string)
Name of the backing index. For naming conventions, see
<<data-streams-generation>>.

`index_uuid`::
(string)
Universally unique identifier (UUID) for the index.
=====

`generation`::
(integer)
Current <<data-streams-generation,generation>> for the data stream. This number
acts as a cumulative count of the stream's backing indices, including
deleted indices.

`status`::
(string)
<<cluster-health,Health status>> of the data stream.
+
This health status is based on the state of the primary and replica shards of
the stream's backing indices.
+
.Values for `status`
[%collapsible%open]
=====
`green`:::
All shards are assigned.

`yellow`:::
All primary shards are assigned, but one or more replica shards are
unassigned.

`red`:::
One or more primary shards are unassigned, so some data is unavailable.
=====

`template`::
(string)
Name of the index template used to create the data stream's backing indices.
+
The template's index pattern must match the name of this data stream. See
<<create-a-data-stream-template>>.

`ilm_policy`::
(string)
Name of the current {ilm-init} lifecycle policy in the stream's matching index
template. This lifecycle policy is set in the `index.lifecycle.name` setting.
+
If the template does not include a lifecycle policy, this property is not
included in the response.
+
NOTE: A data stream's backing indices may be assigned different lifecycle
policies. To retrieve the lifecycle policy for individual backing indices,
use the <<indices-get-settings,get index settings API>>.
====

[[get-data-stream-api-example]]
==== {api-examples-title}

[source,console]
----
GET _data_stream/my-data-stream*
----

The API returns the following response:

[source,console-result]
----
{
  "data_streams": [
    {
      "name": "my-data-stream",
      "timestamp_field": {
        "name": "@timestamp",
        "mapping": {
          "type": "date"
        }
      },
      "indices": [
        {
          "index_name": ".ds-my-data-stream-000001",
          "index_uuid": "xCEhwsp8Tey0-FLNFYVwSg"
        },
        {
          "index_name": ".ds-my-data-stream-000002",
          "index_uuid": "PA_JquKGSiKcAKBA8DJ5gw"
        }
      ],
      "generation": 2,
      "status": "GREEN",
      "template": "my-index-template",
      "ilm_policy": "my-lifecycle-policy"
    },
    {
      "name": "my-data-stream_two",
      "timestamp_field": {
        "name": "@timestamp",
        "mapping": {
          "type": "date"
        }
      },
      "indices": [
        {
          "index_name": ".ds-my-data-stream_two-000001",
          "index_uuid": "3liBu2SYS5axasRt6fUIpA"
        }
      ],
      "generation": 1,
      "status": "YELLOW",
      "template": "my-index-template",
      "ilm_policy": "my-lifecycle-policy"
    }
  ]
}
----
// TESTRESPONSE[s/"index_uuid": "xCEhwsp8Tey0-FLNFYVwSg"/"index_uuid": $body.data_streams.0.indices.0.index_uuid/]
// TESTRESPONSE[s/"index_uuid": "PA_JquKGSiKcAKBA8DJ5gw"/"index_uuid": $body.data_streams.0.indices.1.index_uuid/]
// TESTRESPONSE[s/"index_uuid": "3liBu2SYS5axasRt6fUIpA"/"index_uuid": $body.data_streams.1.indices.0.index_uuid/]
// TESTRESPONSE[s/"status": "GREEN"/"status": "YELLOW"/]