anchor.diff:  Just as in <<docs-update,Update API>> you can set `ctx.op` to change the
   operation that is executed:
   
  -
  +[horizontal]
   `noop`::
   
   Set `ctx.op = "noop"` if your script decides that it doesn't have to make any
  
positive.code: [[docs-update-by-query-cancel-task-api]]
  === Works with the Cancel Task API
  
  Any Update By Query can be canceled using the <<tasks,Task Cancel API>>:
  
  [source,js]
  --------------------------------------------------
  
negative.code: wait_time = target_time - write_time = 2 seconds - .5 seconds = 1.5 seconds
  --------------------------------------------------
  
  Since the batch is issued as a single `_bulk` request, large batch sizes will
  cause Elasticsearch to create many requests and then wait for a while before
  starting the next set. This is "bursty" instead of "smooth". The default is `-1`.
  
  