How to Create Index Alias in Elasticsearch Quickly

To create an index alias in Elasticsearch, use the PUT /_aliases API with a JSON body specifying the alias name and the target index. This lets you refer to one or more indices by a single alias name for easier querying and management.

Syntax

The basic syntax to create an alias uses the PUT /_aliases endpoint with a JSON body. You specify the index and the alias name under the actions array.

• actions: List of operations to perform.
• add: Operation to add an alias.
• index: The name of the existing index.
• alias: The name of the alias to create.

json

PUT /_aliases
{
  "actions": [
    {
      "add": {
        "index": "my_index",
        "alias": "my_alias"
      }
    }
  ]
}

Example

This example creates an alias named logs_alias for the index logs_2024. After this, you can query logs_alias instead of the full index name.

json

PUT /_aliases
{
  "actions": [
    {
      "add": {
        "index": "logs_2024",
        "alias": "logs_alias"
      }
    }
  ]
}

Output

{
  "acknowledged": true
}

Common Pitfalls

Common mistakes when creating aliases include:

• Using PUT /{alias} instead of PUT /_aliases which is incorrect for alias creation.
• Trying to create an alias for a non-existing index.
• Not using the actions array format, which is required.

Always check the index exists before adding an alias.

json

### Wrong way (missing actions array):
PUT /_aliases
{
  "add": {
    "index": "my_index",
    "alias": "my_alias"
  }
}

### Right way:
PUT /_aliases
{
  "actions": [
    {
      "add": {
        "index": "my_index",
        "alias": "my_alias"
      }
    }
  ]
}

Quick Reference

Operation	Description	Example
Add alias	Create an alias for an index	PUT /_aliases {"actions":[{"add":{"index":"idx","alias":"alias"}}]}
Remove alias	Delete an alias from an index	POST /_aliases {"actions":[{"remove":{"index":"idx","alias":"alias"}}]}
Check alias	Get indices for an alias	GET /alias_name

Key Takeaways

Use the PUT /_aliases API with an actions array to create index aliases.

Aliases let you query one or more indices with a simple name.

Always ensure the target index exists before adding an alias.

The JSON body must include the add action inside an actions array.

Check your alias with GET /alias_name to confirm creation.