when the amount of messages reach the maxsize of retention.bytes ,the kafka will delete messages,the offset will be reset to zero?

Question

I am new to kafka, when we use kafka,we can set the retention.bytes. say we set to 1GB, if the amount of message reach 1GB,kafka will delete messages.I want to ask that the offset will be reset to zero? second, the consumer set auto.offset.reset to largest, after kafka delete the messages, what offset will the consumer start?

Answer 1

For your question #1, with honoring both size-based and time-based policies, log might be rolled over to a new empty log segment. New log segment file's starting offset will be the offset of the next message that will be appended to the log.

For your question #2, it depends. If the offset tracked by consumer is out of range due to the message deletion, then it will be reset to the largest offset.