Imagine that there are 5 consumers in a consumer group and a topic with 5 partitions.

Let’s say one of the consumer’s within the group rewinds data for its partition.

How the single topic __consumer_offsets affected by this ?

And what happens to the other messages sent to the other consumers within that group ?

1. Do all other consumers get backdated message now that one consumer has done a rewind ? Or is it done on a partition wise basis, ie. consumers connecting to that partition will now receive that older messages only.
2. Does the __consumer_offsets topic record the offset partition wise or topic wise ? That is, it does not care about the partitions within a topic but only about the topic itself.