Index settings

You can specify index settings at index creation. There are two types of index settings:

• Static index settings are settings that you cannot update while the index is open. To update a static setting, you must close the index, update the setting, and then reopen the index.
• Dynamic index settings are settings that you can update at any time.

Specifying a setting when creating an index

When creating an index, you can specify its static or dynamic settings as follows:

PUT /testindex
{
  "settings": {
    "index.number_of_shards": 1,
    "index.number_of_replicas": 2
  }
}

Static index settings

The following table lists all available static index settings.

Updating a static index setting

You can update a static index setting only on a closed index. The following example demonstrates updating the index codec setting.

First, close an index:

POST /testindex/_close

Then update the settings by sending a request to the _settings endpoint:

PUT /testindex/_settings
{
  "index": {
    "codec": "zstd_no_dict",
    "codec.compression_level": 3
  }
}

Last, reopen the index to enable read and write operations:

POST /testindex/_open

For more information about updating settings, including supported query parameters, see Update settings.

Dynamic index settings

The following table lists all available dynamic index settings.

Updating a dynamic index setting

You can update a dynamic index setting at any time through the API. For example, to update the refresh interval, use the following request:

PUT /testindex/_settings
{
  "index": {
    "refresh_interval": "2s"
  }
}

For more information about updating settings, including supported query parameters, see Update settings.

Related articles

• Index codecs