What are Inbox and Outbox patterns?

Inbox and Outbox patterns are approaches for reliable message processing and integration between services.

• The Inbox pattern is used for guaranteed processing of incoming messages. The service saves the incoming message in a special table (Inbox), processes it, and marks it as processed. This helps prevent message loss or duplicate processing.

• The Outbox pattern is used for reliable message sending. The service first saves the event or message in the Outbox table within a transaction with the main operation, and then a separate process reads the Outbox and sends messages to a queue or another service. This ensures data and message consistency.

Both patterns help build resilient distributed systems with guaranteed delivery and message processing.