10.6 Watch it fail

Start the application and open the console as a member of staff, on Executions:

dotnet run --urls http://localhost:5080

The first restock runs at once, and the next a minute later. Take the supplier down:

curl -X POST http://localhost:5080/dev/supplier/down

The next restock fails, and the hook tells staff. Then it runs again and fails again, and again after a longer wait:

fail: Trax.Effect.Services.ServiceTrain.ServiceTrain[0]
      Caught Exception (Shopfront.Suppliers.SupplierUnavailableException) with Message (The supplier's feed did not answer.).
warn: Shopfront.Staff.LoggingStaffNotifier[0]
      For staff: Shopfront.Trains.Restock.IRestockTrain failed: The supplier's feed did not answer.

The runs' start times show the backoff. Each retry runs on the scheduler's next pass after its delay has gone by, so the gaps are a little longer than five and ten seconds:

 id | train_state | failure_class |          start_time
----+-------------+---------------+-------------------------------
  6 | completed   | unclassified  | 2026-10-18 20:16:57.188407+00
 55 | failed      | transient     | 2026-10-18 20:18:02.674244+00
 65 | failed      | transient     | 2026-10-18 20:18:13.79591+00
 77 | failed      | transient     | 2026-10-18 20:18:27.971728+00

The console's Executions shows the three failed runs of IRestockTrain, each classified Transient. Dead letters now holds the restock: the manifest stopped. It will not run again, on its schedule or otherwise, until someone looks at it.

SDK Reference

Schedule | AddScheduler | How retries work | Resolve a dead letter | AddLifecycleHook

Next: 10.7 Bring it back