That page is packed full of super design! Many of these features we would
find useful, I think. One thing I found myself not knowing is what a
consumer rebalance actually is.
Is a rebalance when the thread that is consuming a particular partition
dies, this is detected and the partition is reassigned to a new thread, thus
violating manual partitioning?
Or is a rebalance when a broker dies and new leader partitions are elected?
The simple consumer must get told of a leader election and this is nothing
to do with rebalance, is it so?