kafka ack=all and min-isr

Question

Summary

The docs and code comments for Kafka suggest that when the producer setting acks is set to all then an ack will only b

Answer 1

Thanks to Ismael on the jira-dev mailing list.

The key point is the line:

if(leaderReplica.highWatermark.messageOffset >= requiredOffset) {

The high watermark only moves when all the replicas in ISR have that particular offset.