Scale
Introduced 3.0
The Scale API allows you to enable or disable the search_only mode on an index. When an index is in search_only mode, it retains only its search replicas and scales down primary and regular replica shards. This optimization helps reduce resource consumption during periods of low write activity while maintaining search capabilities.
This feature supports scenarios such as scale-to-zero deployments and reader/writer separation patterns, which can significantly improve resource utilization and reduce costs in production environments.
If you are using the Security plugin, you must have the manage index privileges.
Endpoints
POST /<index>/_scale
Path parameters
The following table lists the available path parameters.
| Parameter | Required | Data type | Description |
|---|---|---|---|
index | Required | String | The name of the index to scale. Wildcards are not supported. |
Request body fields
The following table lists the available request body fields.
| Field | Required | Data type | Description |
|---|---|---|---|
search_only | Required | Boolean | When true, enables search-only mode on the index. When false, disables search-only mode and restores the index to normal operations. |
Example requests
Enable search-only mode
The following request enables search-only mode for an index named my-index:
POST /my-index/_scale
{
"search_only": true
}
Disable search-only mode
The following request disables search-only mode and returns the index to normal operations:
POST /my-index/_scale
{
"search_only": false
}
Example response
The API returns the following response:
{
"acknowledged": true
}