“Records written as a part of a committed transaction could vanish, never to be seen again.”
Bufstream sells Kafka compatibility on top of S3. Jepsen found three safety bugs and two liveness bugs, including committed transactions that lost writes in 0.1.2 and consumers whose poll() came back empty with acknowledged records unread. Buf fixed its five by 0.1.3. The four issues in Kafka itself stay open, so “Kafka-compatible” includes Kafka’s transaction bugs.