Create index from source API

PUT /_create_from/<source>/<dest>

POST/_create_from/<source>/<dest>

This api allows you to add a new index to an Elasticsearch cluster, using an existing source index as a basis for the new index. The settings and mappings from the source index will copied over to the destination index. You can also provide override settings and mappings which will be combined with the source settings and mappings when creating the destination index.

Start by creating a source index that we’ll copy using this API.

resp = client.indices.create(
    index="my-index",
    settings={
        "index": {
            "number_of_shards": 3,
            "blocks.write": True
        }
    },
    mappings={
        "properties": {
            "field1": {
                "type": "text"
            }
        }
    },
)
print(resp)

const response = await client.indices.create({
  index: "my-index",
  settings: {
    index: {
      number_of_shards: 3,
      "blocks.write": true,
    },
  },
  mappings: {
    properties: {
      field1: {
        type: "text",
      },
    },
  },
});
console.log(response);

PUT /my-index
{
  "settings": {
    "index": {
      "number_of_shards": 3,
      "blocks.write": true
    }
  },
  "mappings": {
    "properties": {
        "field1": { "type": "text" }
    }
  }
}

Now we create a destination index from the source index. This new index will have the same mappings and settings as the source index.

resp = client.indices.create_from(
    source="my-index",
    dest="my-new-index",
    create_from=None,
)
print(resp)

const response = await client.indices.createFrom({
  source: "my-index",
  dest: "my-new-index",
  create_from: null,
});
console.log(response);

POST _create_from/my-index/my-new-index

Alternatively, we could override some of the source’s settings and mappings. This will use the source settings and mappings as a basis and combine these with the overrides to create the destination settings and mappings.

resp = client.indices.create_from(
    source="my-index",
    dest="my-new-index",
    create_from={
        "settings_override": {
            "index": {
                "number_of_shards": 5
            }
        },
        "mappings_override": {
            "properties": {
                "field2": {
                    "type": "boolean"
                }
            }
        }
    },
)
print(resp)

const response = await client.indices.createFrom({
  source: "my-index",
  dest: "my-new-index",
  create_from: {
    settings_override: {
      index: {
        number_of_shards: 5,
      },
    },
    mappings_override: {
      properties: {
        field2: {
          type: "boolean",
        },
      },
    },
  },
});
console.log(response);

POST _create_from/my-index/my-new-index
{
  "settings_override": {
    "index": {
      "number_of_shards": 5
    }
  },
  "mappings_override": {
    "properties": {
        "field2": { "type": "boolean" }
    }
  }
}

Since the destination index is empty, we very likely will want to write into the index after creation. This would not be possible if the source index contains an index write block which is copied over to the destination index. One way to handle this is to remove the index write block using a settings override. For example, the following settings override removes all index blocks.

resp = client.indices.create_from(
    source="my-index",
    dest="my-new-index",
    create_from={
        "settings_override": {
            "index": {
                "blocks.write": None,
                "blocks.read": None,
                "blocks.read_only": None,
                "blocks.read_only_allow_delete": None,
                "blocks.metadata": None
            }
        }
    },
)
print(resp)

const response = await client.indices.createFrom({
  source: "my-index",
  dest: "my-new-index",
  create_from: {
    settings_override: {
      index: {
        "blocks.write": null,
        "blocks.read": null,
        "blocks.read_only": null,
        "blocks.read_only_allow_delete": null,
        "blocks.metadata": null,
      },
    },
  },
});
console.log(response);

POST _create_from/my-index/my-new-index
{
  "settings_override": {
    "index": {
      "blocks.write": null,
      "blocks.read": null,
      "blocks.read_only": null,
      "blocks.read_only_allow_delete": null,
      "blocks.metadata": null
    }
  }
}

Since this is a common scenario, index blocks are actually removed by default. This is controlled with the parameter remove_index_blocks, which defaults to true. If we want the destination index to contains the index blocks from the source index, we can do the following:

resp = client.indices.create_from(
    source="my-index",
    dest="my-new-index",
    create_from={
        "remove_index_blocks": False
    },
)
print(resp)

const response = await client.indices.createFrom({
  source: "my-index",
  dest: "my-new-index",
  create_from: {
    remove_index_blocks: false,
  },
});
console.log(response);

POST _create_from/my-index/my-new-index
{
  "remove_index_blocks": false
}