preserve_existing

action: index_settings
description: "Change settings for selected indices"
options:
  index_settings:
    index:
      refresh_interval: 5s
  ignore_unavailable: False
  preserve_existing: False
filters:
- filtertype: ...

This setting must be either True or False.

If preserve_existing is set to True, and the configuration attempts to push a setting to an index that already has any value for that setting, the existing setting will be preserved, and remain unchanged.

The default value of this setting is False