I'm using elapsed plugin.
I have start event, and end event.
  if [trigger_status] == "PROBLEM" {
       mutate{ add_tag => [ "taskStarted" ]}
  }
  if [trigger_status] == "OK" {
       mutate{ add_tag => [ "taskTerminated" ]}
  }
   elapsed {
       start_tag => "taskStarted"
       end_tag => "taskTerminated"
       unique_id_field => "trigger_id"
   }
Is it possible to add TAG at start event when end event get match?
maybe, searching for the last trigger_id and adding the tag...