anchor.diff:  [[cluster-update-settings]]
   == Cluster Update Settings
   
  -Allows to update cluster wide specific settings. Settings updated can
  -either be persistent (applied across restarts) or transient (will not
  -survive a full cluster restart). Here is an example:
  +Use this API to review and change cluster-wide settings. 
  +
  +To review cluster settings:
  +
  +[source,js]
  +--------------------------------------------------
  +GET /_cluster/settings
  +--------------------------------------------------
  +// CONSOLE
  +
  +Updates to settings can be persistent, meaning they apply across restarts, or transient, where they don't 
  +survive a full cluster restart. Here is an example of a persistent update:
   
   [source,js]
   --------------------------------------------------
  
positive.code: --------------------------------------------------
  // TESTRESPONSE[s/\.\.\./"acknowledged": true,/]
  
  Resetting persistent or transient settings can be done by assigning a
  `null` value. If a transient setting is reset, the persistent setting
  is applied if available. Otherwise Elasticsearch will fallback to the setting
  defined at the configuration file or, if not existent, to the default
  value. Here is an example:
  
  [source,js]
  --------------------------------------------------
  
negative.code: --------------------------------------------------
  // CONSOLE
  
  The response to an update returns the changed setting, as in this response to the transient example:
  
  [source,js]
  --------------------------------------------------
  