anchor.diff:  (integer)
   Total number of successful get operations.
   
  +`indices.get.exists_time`::
  +(<<time-units,time value>>)
  +Time spent performing successful get operations.
  +
   `indices.get.exists_time_in_millis`::
   (integer)
   Time in milliseconds
  
positive.code: (integer)
  Total number of scroll operations.
  
  `indices.search.scroll_time_in_millis`::
  (integer)
  Time in milliseconds
  
negative.code: (integer)
  Number of flush periodic operations.
  
  `indices.flush.total_time`::
  (<<time-units,time value>>)
  Total time spent performing flush operations.
  
  `indices.flush.total_time_in_millis`::
  (integer)
  Total time in milliseconds
  