anchor.diff:  Total number of RX (receive) packets received by the node during internal
   cluster communication.
   
  +`transport.rx_size`::
  +(<<byte-units,byte value>>)
  +Size of RX packets received by the node during internal cluster communication.
  +
   `transport.rx_size_in_bytes`::
   (integer)
   Size, in bytes, of RX packets received by the node during internal cluster
  
positive.code: [%collapsible]
  ====
  `process.timestamp`::
      Last time the process statistics have been refreshed.
  
  `process.open_file_descriptors`::
      Number of opened file descriptors associated with the current process, or -1 
      if not supported.
  
  `process.max_file_descriptors`::
      Maximum number of file descriptors allowed on the system, or -1 if not 
      supported.
  
  `process.cpu.percent`::
      CPU usage in percent, or -1 if not known at the time the stats are computed
  
  `process.cpu.total_in_millis`::
      CPU time (in milliseconds) used by the process on which the Java virtual 
      machine is running, or -1 if not supported.
  
  `process.mem.total_virtual_in_bytes`::
      Size in bytes of virtual memory that is guaranteed to be available to the 
      running process.
  ====
  
negative.code:     (integer)
      Total number of documents ingested during the lifetime of this node.
  
  `ingest.total.time`::
      (<<time-units,time value>>)
      Total time spent preprocessing ingest documents during the lifetime of this
      node.
  
  `ingest.total.time_in_millis`::
      (integer)
      Total time, in milliseconds, spent preprocessing ingest documents during the
      lifetime of this node.
  
  `ingest.total.current`::
      (integer)
      Total number of documents currently being ingested.
  