LEARN. PRACTICE. GROW.Concept and mechanism
A work queue with settlement, a stream with independent consumers, and event notifications address different needs. Choose semantics before the product. With Service Bus, an effect can complete before acknowledgment reaches the broker; consumers must handle repetition. Event Hubs supports independent positions through consumer groups and checkpoints within retention. With cache-aside, a database write does not automatically update every cache: define invalidation and acceptable staleness for each flow.
Guided application
To persist state and announce an event, a transactional outbox can store both in one local transaction. A relay publishes later with monitoring and duplicate handling. Do not present this as universal exactly-once delivery. For infrastructure deployment, interpret the what-if plan and replacement effects. Compiling a template does not demonstrate data preservation, compatibility, or service recovery.
A valuation was persisted, but its event was lost before publication. Durable intent supports resuming delivery and observing backlog.
Common pitfalls
Treating all event services as equivalent; using retries as atomicity; retaining stale cache without an explicit policy.
Related topics: Networking and complete-service migration · Identity and access boundaries
Specify what happens between commit, delivery, acknowledgment, and repetition.
Reference: Transactional outbox · AZ-305 objectives 2026-04-17