outbox

To prevent lost domain events, the outbox pattern persists events and OutboxMessage records atomically via a single SaveChangesAsync call using IUnitOfWork, eliminating race conditions between database commits and external message broker publishing.

The outbox pattern saves domain events and OutboxMessage records together in one database transaction. You need it in EF Core microservices when cross-service integration via Azure Service Bus requires guaranteed event persistence without race conditions between commits and publishing.

Implement a singleton ServiceBusPublisher using Task.Run and lock-based concurrency that creates a DI scope for database access, reads OutboxMessage records in batches of 200, publishes each message, deletes it, and saves changes to guarantee at-least-once delivery.

The outbox pattern supports idempotency by using FK-based OutboxMessage wrapping of Event via a shared primary key navigation property rather than serializing event bodies, combined with batched reads of 200 and at-least-once delivery semantics to prevent duplicate processing.

Event publishing fails because database commits and external broker publishing are not atomic. The outbox pattern solves this by persisting domain events and OutboxMessage records together via IUnitOfWork and a single SaveChangesAsync call, then using a background publisher to dispatch them reliably.

Yes, the outbox pattern uses FK-based OutboxMessage wrapping of Event via a navigation property with a shared primary key rather than serializing event bodies, maintaining referential integrity within EF Core while enabling atomic persistence through IUnitOfWork and SaveChangesAsync.