IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.

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Set up a data stream

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Set up a data stream

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To set up a data stream, follow these steps:

You can also convert an index alias to a data stream.

If you use Fleet or Elastic Agent, skip this tutorial. Fleet and Elastic Agent set up data streams for you. See Fleet’s data streams documentation.

Create an index lifecycle policy

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While optional, we recommend using ILM to automate the management of your data stream’s backing indices. ILM requires an index lifecycle policy.

To create an index lifecycle policy in Kibana, open the main menu and go to Stack Management > Index Lifecycle Policies. Click Create policy.

You can also use the create lifecycle policy API.

PUT _ilm/policy/my-lifecycle-policy
{
  "policy": {
    "phases": {
      "hot": {
        "actions": {
          "rollover": {
            "max_primary_shard_size": "50gb"
          }
        }
      },
      "warm": {
        "min_age": "30d",
        "actions": {
          "shrink": {
            "number_of_shards": 1
          },
          "forcemerge": {
            "max_num_segments": 1
          }
        }
      },
      "cold": {
        "min_age": "60d",
        "actions": {
          "searchable_snapshot": {
            "snapshot_repository": "found-snapshots"
          }
        }
      },
      "frozen": {
        "min_age": "90d",
        "actions": {
          "searchable_snapshot": {
            "snapshot_repository": "found-snapshots"
          }
        }
      },
      "delete": {
        "min_age": "735d",
        "actions": {
          "delete": {}
        }
      }
    }
  }
}

Create component templates

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A data stream requires a matching index template. In most cases, you compose this index template using one or more component templates. You typically use separate component templates for mappings and index settings. This lets you reuse the component templates in multiple index templates.

When creating your component templates, include:

A date or date_nanos mapping for the @timestamp field. If you don’t specify a mapping, Elasticsearch maps @timestamp as a date field with default options.
Your lifecycle policy in the index.lifecycle.name index setting.

Use the Elastic Common Schema (ECS) when mapping your fields. ECS fields integrate with several Elastic Stack features by default.

If you’re unsure how to map your fields, use runtime fields to extract fields from unstructured content at search time. For example, you can index a log message to a wildcard field and later extract IP addresses and other data from this field during a search.

To create a component template in Kibana, open the main menu and go to Stack Management > Index Management. In the Index Templates view, click Create component template.

You can also use the create component template API.

response = client.cluster.put_component_template(
  name: 'my-mappings',
  body: {
    template: {
      mappings: {
        properties: {
          "@timestamp": {
            type: 'date',
            format: 'date_optional_time||epoch_millis'
          },
          message: {
            type: 'wildcard'
          }
        }
      }
    },
    _meta: {
      description: 'Mappings for @timestamp and message fields',
      "my-custom-meta-field": 'More arbitrary metadata'
    }
  }
)
puts response

response = client.cluster.put_component_template(
  name: 'my-settings',
  body: {
    template: {
      settings: {
        "index.lifecycle.name": 'my-lifecycle-policy'
      }
    },
    _meta: {
      description: 'Settings for ILM',
      "my-custom-meta-field": 'More arbitrary metadata'
    }
  }
)
puts response

# Creates a component template for mappings
PUT _component_template/my-mappings
{
  "template": {
    "mappings": {
      "properties": {
        "@timestamp": {
          "type": "date",
          "format": "date_optional_time||epoch_millis"
        },
        "message": {
          "type": "wildcard"
        }
      }
    }
  },
  "_meta": {
    "description": "Mappings for @timestamp and message fields",
    "my-custom-meta-field": "More arbitrary metadata"
  }
}

# Creates a component template for index settings
PUT _component_template/my-settings
{
  "template": {
    "settings": {
      "index.lifecycle.name": "my-lifecycle-policy"
    }
  },
  "_meta": {
    "description": "Settings for ILM",
    "my-custom-meta-field": "More arbitrary metadata"
  }
}

Create an index template

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Use your component templates to create an index template. Specify:

One or more index patterns that match the data stream’s name. We recommend using our data stream naming scheme.
That the template is data stream enabled.
Any component templates that contain your mappings and index settings.
A priority higher than 200 to avoid collisions with built-in templates. See Avoid index pattern collisions.

To create an index template in Kibana, open the main menu and go to Stack Management > Index Management. In the Index Templates view, click Create template.

You can also use the create index template API. Include the data_stream object to enable data streams.

response = client.indices.put_index_template(
  name: 'my-index-template',
  body: {
    index_patterns: [
      'my-data-stream*'
    ],
    data_stream: {},
    composed_of: [
      'my-mappings',
      'my-settings'
    ],
    priority: 500,
    _meta: {
      description: 'Template for my time series data',
      "my-custom-meta-field": 'More arbitrary metadata'
    }
  }
)
puts response

PUT _index_template/my-index-template
{
  "index_patterns": ["my-data-stream*"],
  "data_stream": { },
  "composed_of": [ "my-mappings", "my-settings" ],
  "priority": 500,
  "_meta": {
    "description": "Template for my time series data",
    "my-custom-meta-field": "More arbitrary metadata"
  }
}

Create the data stream

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Indexing requests add documents to a data stream. These requests must use an op_type of create. Documents must include a @timestamp field.

To automatically create your data stream, submit an indexing request that targets the stream’s name. This name must match one of your index template’s index patterns.

PUT my-data-stream/_bulk
{ "create":{ } }
{ "@timestamp": "2099-05-06T16:21:15.000Z", "message": "192.0.2.42 - - [06/May/2099:16:21:15 +0000] \"GET /images/bg.jpg HTTP/1.0\" 200 24736" }
{ "create":{ } }
{ "@timestamp": "2099-05-06T16:25:42.000Z", "message": "192.0.2.255 - - [06/May/2099:16:25:42 +0000] \"GET /favicon.ico HTTP/1.0\" 200 3638" }

POST my-data-stream/_doc
{
  "@timestamp": "2099-05-06T16:21:15.000Z",
  "message": "192.0.2.42 - - [06/May/2099:16:21:15 +0000] \"GET /images/bg.jpg HTTP/1.0\" 200 24736"
}

You can also manually create the stream using the create data stream API. The stream’s name must still match one of your template’s index patterns.

PUT _data_stream/my-data-stream

Secure the data stream

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Use index privileges to control access to a data stream. Granting privileges on a data stream grants the same privileges on its backing indices.

For an example, see Data stream privileges.

Convert an index alias to a data stream

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Prior to Elasticsearch 7.9, you’d typically use an index alias with a write index to manage time series data. Data streams replace this functionality, require less maintenance, and automatically integrate with data tiers.

To convert an index alias with a write index to a data stream with the same name, use the migrate to data stream API. During conversion, the alias’s indices become hidden backing indices for the stream. The alias’s write index becomes the stream’s write index. The stream still requires a matching index template with data stream enabled.

POST _data_stream/_migrate/my-time-series-data

Get information about a data stream

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To get information about a data stream in Kibana, open the main menu and go to Stack Management > Index Management. In the Data Streams view, click the data stream’s name.

You can also use the get data stream API.

response = client.indices.get_data_stream(
  name: 'my-data-stream'
)
puts response

GET _data_stream/my-data-stream

Delete a data stream

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To delete a data stream and its backing indices in Kibana, open the main menu and go to Stack Management > Index Management. In the Data Streams view, click the trash icon. The icon only displays if you have the delete_index security privilege for the data stream.

You can also use the delete data stream API.

response = client.indices.delete_data_stream(
  name: 'my-data-stream'
)
puts response

DELETE _data_stream/my-data-stream

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