configuration.md

layout	title	parent	nav_order
default	Configuration	Elasticsearch	1

Elasticsearch configuration

Most Elasticsearch configuration can take place in the cluster settings API. Certain operations require you to modify elasticsearch.yml and restart the cluster.

Whenever possible, use the cluster settings API instead; elasticsearch.yml is local to each node, whereas the API applies the setting to all nodes in the cluster.

Cluster settings API

The first step in changing a setting is to view the current settings:

GET _cluster/settings?include_defaults=true

For a more concise summary of non-default settings:

GET _cluster/settings

Three categories of setting exist in the cluster settings API: persistent, transient, and default. Persistent settings, well, persist after a cluster restart. After a restart, Elasticsearch clears transient settings.

If you specify the same setting in multiple places, Elasticsearch uses the following precedence:

1. Transient settings
2. Persistent settings
3. Settings from elasticsearch.yml
4. Default settings

To change a setting, just specify the new one as either persistent or transient. This example shows the flat settings form:

PUT /_cluster/settings
{
  "persistent" : {
    "action.auto_create_index" : false
  }
}

You can also use the expanded form, which lets you copy and paste from the GET response and change existing values:

PUT /_cluster/settings
{
  "persistent": {
    "action": {
      "auto_create_index": false
    }
  }
}

---

Configuration file

You can find elasticsearch.yml in /usr/share/elasticsearch/config/elasticsearch.yml (Docker) or /etc/elasticsearch/elasticsearch.yml (RPM and DEB) on each node.

The demo configuration includes a number of settings for the security plugin that you should modify before using Open Distro for a production workload. To learn more, see Security.