Reliability and Redunancy for Periodic Tasks

[treuherz]

If a Periodic Task is set up and the Asynq deployment is down, for whatever reason, when the task would be enqueued, can Asynq recover from this when it comes back up? I'm looking for functionality like anacron which stores enough state to catch if a cron job was missed when a machine was down.

Second, related question: #342 says that multiple Asynq instances on the same Redis queue will be fine - is that also true of Period Tasks or will we get duplicates?