Expense Outbox and Delivery

Summary

Expense has an active hosted relay. Pending and Failed rows are selected oldest-first in bounded batches, published sequentially, and changed to Processed after successful broker publication.

Outbox lifecycle

Confirmed

• Domain-to-contract mapping happens before the local save commits.
• Outbox event identity is unique.
• Pending and Failed work is eligible for relay selection.
• Selection orders by occurrence time within each batch.
• A publish result indicating unavailability marks the row Failed.
• Exceptions also mark the row Failed and increment its retry count.
• The hosted relay catches iteration failures and continues after its polling delay.
• Successfully published rows are marked Processed.

Not implemented

• Expense-specific dead-letter storage
• Retry ceiling
• Exponential backoff
• Poison-message quarantine
• Administrative replay command
• Exactly-once delivery guarantee

Requires confirmation

Relay monitoring, manual recovery ownership, retention of Processed rows, operational alerts, and safe replay procedures require confirmation.

Source References

• microservices/src/expense-service/Infrastructure/ExpenseDbContext.cs
• microservices/src/expense-service/Infrastructure/Persistence.cs
• microservices/src/shared-kernel/Outbox/OutboxMessage.cs
• microservices/src/shared-kernel/Messaging/OutboxProcessor.cs
• microservices/src/expense-service/Messaging/OutboxRelayHostedService.cs

Related Articles

• Expense events documentation
• Expense technical documentation
• Expense database documentation

See Also

• Expense API documentation
• Expense module

Keywords

• Expense events
• Outbox and Delivery
• Integration contracts

Revision Information

• Status: Draft
• Last reviewed: 2026-07-16
• Review cycle: Quarterly