anchor.diff:  requests with a queue (optionally bounded) for pending requests that
   have no threads to service them.
   
  -The `size` parameter controls the number of threads, and defaults to the
  -number of cores times 5.
  +The `size` parameter controls the number of threads.
   
   The `queue_size` allows to control the size of the queue of pending
   requests that have no threads to execute them. By default, it is set to
  
positive.code: There are a few use-cases for explicitly overriding the `processors`
  setting:
  
  . If you are running multiple instances of Elasticsearch on the same
  host but want Elasticsearch to size its thread pools as if it only has a
  fraction of the CPU, you should override the `processors` setting to the
  desired fraction (e.g., if you're running two instances of Elasticsearch
  on a 16-core machine, set `processors` to 8). Note that this is an
  expert-level use-case and there's a lot more involved than just setting
  the `processors` setting as there are other considerations like changing
  the number of garbage collector threads, pinning processes to cores,
  etc.
  . Sometimes the number of processors is wrongly detected and in such
  cases explicitly setting the `processors` setting will workaround such
  issues.
  
negative.code:     queue_size of `1000`.
  
  `analyze`::
      For analyze requests. Thread pool type is `fixed` with a size of `1`, queue 
      size of `16`.
  
  `write`::
      For single-document index/delete/update and bulk requests. Thread pool type
  