Your question is hard to understand.<p><a href="https:&#x2F;&#x2F;kafka.apache.org&#x2F;08&#x2F;design.html" rel="nofollow">https:&#x2F;&#x2F;kafka.apache.org&#x2F;08&#x2F;design.html</a><p>&quot;So effectively Kafka guarantees at-least-once delivery by default ....&quot;<p>Edit: Downvote if you want. I was trying to help you.