An acquisition task may be needed to initiate the processing. The following example shows such a pattern where a wait task is created to check the presence of input data in the acquisition time window 10:00 to 12:00. A task is dedicated to raise a red alarm, by 11:00, if data are not yet arrived, to have operators and analysts aware in advance to be careful about this. wait task runs every 5 minutes and set the data event when input data are found ; it shall sleep 60 seconds, after setting the event, before completing, to ensure the server receives the event and starts the data task, before wait task completion and immediate requeue (cron). data task (validation and preprocessing) will then set the ready event and acq family will become complete, provided underneath tasks are complete or queued, so that rt/wait and late_alert do not run any further.
...