How do you guarantee at-least-once event delivery for a financial transaction?
WHAT IT TESTS: Atomicity of state changes and side effects without 2PC. ANSWER OUTLINE: Write events to a DB outbox in the same transaction as the biz update; a relay polls and publishes to analytics. RED FLAG: Suggesting direct HTTP POSTs or dual writes.
WHAT IT TESTS: Whether you can atomically update state and emit events without distributed transactions. ANSWER OUTLINE: Use a transactional outbox by writing the event to a DB table within the same local transaction that commits the financial update. A separate relay polls the outbox and publishes to the analytics backend, retrying on network failures; because the relay may redeliver, consumers must be idempotent. RED FLAG: Proposing direct HTTP POSTs from the application thread after commit, or dual writes that risk inconsistency on crashes.
Read the original → microservices.io
- #transactional outbox
- #at-least-once delivery
- #analytics
- #microservices
- #data consistency
Get five bites like this every day.
Tezvyn delivers a daily feed of 60-second tech bites with quizzes to lock in what you learn.