anchor.diff:          02:00:00.000Z
   ....
   
  +Rerunning thus serves two purposes: besides the main use of rerunning
  +a slot, it can also be used to _backfill_ data.
  +
   === Continuous Delivery of Workflows
   
   Changing a workflow definition in Celos is as simple as updating the
  
positive.code: 
  === Notes
  
  All times in Celos use the UTC timezone exclusively.
  
  === Weaknesses of the Celos architecture
  
  ==== Single master
  
  This might not be as bad as it sounds.  The reason is that during
  normal operation, most workflows will usually be mostly successful.
  
negative.code: which, if they are "purely functional" will bring the system back to a
  mostly normal state.
  
  ===== Changing the schedule of a workflow
  
  Changing the schedule of a workflow (e.g. from "at the hour" to "5
  minutes past the hour") means that the existing slot files in the
  state database no longer line up with the workflow's (new) schedule,
  making them effectively lost.
  
  ===== Errors during job submission to Oozie do not bubble up into the UI
  
  If an error happens during job submission to Oozie (e.g. because the
  Oozie workflow directory is missing, or the workflow.xml contains a
  