I’m thrilled that we have hit an exciting milestone the Apache Kafka® community has long been waiting for: we have introduced exactly-once semantics in Kafka in the 0.11 release and Confluent Platform 3.3. In this post, I’d like to tell you what Kafka’s exactly-once semantics mean, why it is a hard problem, and how the new idempotence and transactions features in Kafka enable correct exactly-once
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