问题
producer sends messages 1, 2, 3, 4
consumer receives messages 1, 2, 3, 4
consumer crashes/disconnects
producer sends messages 5, 6, 7
consumer comes back up and should receive messages starting from 5 instead of 7
For this kind of result, which offset value I have to use and what are the other changes/configurations need to do
回答1:
When a consumer joins a consumer group it will fetch the last committed offset so it will restart to read from 5, 6, 7 if before crashing it committed the latest offset (so 4).
The earliest and latest values for the auto.offset.reset property is used when a consumer starts but there is no committed offset for the assigned partition. In this case you can chose if you want to re-read all the messages from the beginning (earliest) or just after the last one (latest).
来源：https://stackoverflow.com/questions/48320672/what-is-the-difference-between-kafka-earliest-and-latest-offset-values