Page History

...

To make sure we could recover from broker failure/leader coordinator transition, an in-memory `group.instance.id` map is not enough. We would reuse the _consumer_offsets topic to store the static member map information. When another broker takes over the leadership, it will load the static mapping info together. 

...

We do have some offline discussions on handling leader rejoin case, for example where due to the possible topic assignment change (adding or removing topics), we still need to start a rebalance. However since the broker could also do the subscription monitoring work, we don't actually need to trigger rebalance on leader side blindly based on its rejoin request. However this This is a separate topic from 345 and we could address it in another KIP. 

...