anchor.diff:            "type": "date"
           }
         }
  -    },
  -    "settings": {
  -      "index.lifecycle.name": "logs_policy"
  -    }
  -  }
  -}
  -
  -PUT /logs/_bulk?refresh
  -{"create":{"_index" : "logs"}}
  -{ "@timestamp": "2020-12-08T11:04:05.000Z" }
  -{"create":{"_index" : "logs"}}
  -{ "@timestamp": "2020-12-08T11:06:07.000Z" }
  -{"create":{"_index" : "logs"}}
  -{ "@timestamp": "2020-12-09T11:07:08.000Z" }
  -----
  +    }
  +  }
  +}
  +
  +PUT /_index_template/new_logs_data_stream
  +{
  +  "index_patterns": [ "new_logs*" ],
  +  "data_stream": {
  +    "timestamp_field": "@timestamp"
  +  },
  +  "template": {
  +    "mappings": {
  +      "properties": {
  +        "@timestamp": {
  +          "type": "date"
  +        }
  +      }
  +    }
  +  }
  +}
  +
  +PUT /_data_stream/logs
  +
  +PUT /_data_stream/new_logs
  +----
  +// TESTSETUP
  +
  +[source,console]
  +----
  +DELETE /_data_stream/*
  +
  +DELETE /_index_template/*
  +
  +DELETE /_ilm/policy/logs_policy
  +----
  +// TEARDOWN
   ////
  +
  +[discrete]
  +[[add-new-field-mapping-to-a-data-stream]]
  +=== Add a new field mapping to a data stream
  +
  +To add a mapping for a new field to a data stream, following these steps:
  +
  +. Update the index template used by the data stream. This ensures the new
  +field mapping is added to future backing indices created for the stream.
  ++
  +.*Example*
  +[%collapsible]
  +====
  +`logs_data_stream` is an existing index template used by the `logs` data stream.
  +
  +The following <<indices-templates,put index template>> request adds a mapping
  +for a new field, `message`, to the template.
   
   [source,console]
   ----
  
positive.code:   }
  }
  ----
  // TEST[continued]
  ====
  
  . If you previously changed your {ilm-init} poll interval, change it back to its
  
negative.code: ----
  GET /_resolve/index/new_logs*
  ----
  
  The API returns the following response, indicating no existing targets match
  this pattern.
  