Adv2 Scenario3

Approach #3, saga

1. The UI sends a command to register X and Y onto conference #157. The command is routed to a new Order aggregate.
2. The new Order aggregate, with an ID of 4239, is persisted to the data store.
3. The Order aggregate raises an event that is handled by the ReservationProcess saga.
4. The ReservationProcess saga determines that a command should be sent to the ConferenceSeatsAvailability aggregate with an ID of 157.
5. The ConferenceSeatsAvailability aggregate is re-hydrated from the data store.
6. The total number of seats booked is updated in the ConferenceSeatsAvailability aggregate and it is persisted to the data store.