NestJS · Senior · Question 15 of 75

In Nest microservices over Kafka, what must handlers be prepared for?

1Messages always arrive in global order
2Exactly-once delivery by default
✓Correct answer: At-least-once delivery and redelivery after rebalances, so handlers must be idempotent; ordering is guaranteed only within a partition

Explanation

Choose message keys so related events go to the same partition, and commit offsets only after successful processing.

Further reading

Test yourself

Take the NestJS · Senior quiz: questions and options are shuffled, and you get a review of your mistakes at the end.