title: Kafka Message at-least-once mode at multi-consumer
body: <p>Kafka messaging use at-least-once message delivery to ensure every message to be processed, and uses a message offset to indicates which message is to deliver next.</p>
  
  <p>When there are multiple consumers, if some <strong>deadly</strong> message cause a consumer crash during message processing, will this message be redelivered to other consumers and spread the death? If some <strong>slow</strong> message blocked a single consumer, can other consumers keep going and process subsequent messages?
  Or even worse, if a <strong>slow and deadly</strong> message caused a consumer crash, will it cause other consumers start from its offset again?</p>