How to do it...

The HTTP method to create an index is PUT (but POST also works); the REST URL contains the index name:

http://<server>/<index_name>

To create an index, we must perform the following steps:

1. From the command line, we can execute a PUT call:

PUT /myindex
{
  "settings": {
    "index": {
      "number_of_shards": 2,
      "number_of_replicas": 1
    }
  }
}

1. The result returned by Elasticsearch should be like the following:

{
  "acknowledged" : true,
  "shards_acknowledged" : true,
  "index" : "myindex"
}

1. If the index already exists, a 400 error will be returned:

{
  "error": {
    "root_cause": [
      {
        "type": "resource_already_exists_exception",
        "reason": "index [myindex/xaXAnnwcTUiTePcKGWJw3Q] already exists",
        "index_uuid": "xaXAnnwcTUiTePcKGWJw3Q",
        "index": "myindex"
      }
    ],
    "type": "resource_already_exists_exception",
    "reason": "index [myindex/xaXAnnwcTUiTePcKGWJw3Q] already exists",
    "index_uuid": "xaXAnnwcTUiTePcKGWJw3Q",
    "index": "myindex"
  },
  "status": 400
}