Cluster update settings API

PUT /_cluster/settings

You can configure and update dynamic settings on a running cluster using the cluster update settings API. You can also configure dynamic settings locally on an unstarted or shut down node using elasticsearch.yml.

Updates made using the cluster update settings API can be persistent, which apply across cluster restarts, or transient, which reset after a cluster restart. You can also reset transient or persistent settings by assigning them a null value using the API.

If you configure the same setting using multiple methods, Elasticsearch applies the settings in following order of precedence:

For example, you can apply a transient setting to override a persistent setting or elasticsearch.yml setting. However, a change to an elasticsearch.yml setting will not override a defined transient or persistent setting.

An example of a persistent update:

PUT /_cluster/settings
{
  "persistent" : {
    "indices.recovery.max_bytes_per_sec" : "50mb"
  }
}

An example of a transient update:

PUT /_cluster/settings?flat_settings=true
{
  "transient" : {
    "indices.recovery.max_bytes_per_sec" : "20mb"
  }
}

The response to an update returns the changed setting, as in this response to the transient example:

{
  ...
  "persistent" : { },
  "transient" : {
    "indices.recovery.max_bytes_per_sec" : "20mb"
  }
}

This example resets a setting:

PUT /_cluster/settings
{
  "transient" : {
    "indices.recovery.max_bytes_per_sec" : null
  }
}

The response does not include settings that have been reset:

{
  ...
  "persistent" : {},
  "transient" : {}
}

You can also reset settings using wildcards. For example, to reset all dynamic indices.recovery settings:

PUT /_cluster/settings
{
  "transient" : {
    "indices.recovery.*" : null
  }
}