Chapter 7 of the Symfony for PHP developers track

The messenger raven

6 exercises · 1,570 XP · about 3 h 30 min

This chapter works on: MessengerMessage#[AsMessageHandler]MessageBusInterfaceTransportQueuemessenger:consumein-memoryretry_strategyfailure_transportRetriesRedeliveryStampScheduler#[AsSchedule]RecurringMessageScheduled taskTesting messagesIn-memory queueWorkerDebuggingFailure queue

The chapter's exercises

1. The first raven

   Exercise 1 · 240 XP · 5 objectives checked by tests

   Reservations pour in from the four corners of the kingdom, and Gorm forgets half of the confirmations. So the tavern gets itself an aviary: for every reservation, a raven flies off to deliver the confirmation.

   MessengerMessage#[AsMessageHandler]MessageBusInterface

2. The raven flies in the background

   Exercise 2 · 250 XP · 5 objectives checked by tests

   The raven leaves, that's something. But it leaves during the request: the guild's scroll waits for the bird to be prepared, fed and released before getting its answer. And if the aviary is crowded, the guild waits.

   TransportQueuemessenger:consumein-memory

3. The raven that gets lost

   Exercise 3 · 250 XP · 5 objectives checked by tests

   A raven does not always arrive. The winds turn, dark towers scramble the routes… and some lands are simply out of reach.

   retry_strategyfailure_transportRetriesRedeliveryStamp

4. The evening raven

   Exercise 4 · 250 XP · 5 objectives checked by tests

   Every evening, Gorm wants to know what awaits him the next day: how many tables, how many adventurers. Enough to plan the provisions, and the number of barrels.

   Scheduler#[AsSchedule]RecurringMessageScheduled task

5. Testing the ravens

   Exercise 5 · 260 XP · 5 objectives checked by tests

   The aviary works. Now you need to make sure it will still work in six months, when Pippin has “tidied up” the configuration.

   Testing messagesIn-memory queueWorker

6. 🐉 Boss: the broken aviary

   Exercise 6 · 320 XP · 5 objectives checked by tests

   Pippin wanted to “optimize the aviary”. Since then, Gorm has been getting complaints:

   DebuggingMessengerSchedulerFailure queue