Demystify ConsumerRebalanceListener for specific cases

[zhenik]

Requirements:

1. Consumer properties enable.auto.commit:false
2. Commit offset after processing or last processed record(s)

Does ConsumerRebalanceListener can be useful in these cases:

1. The first risk is the delay in next pool, because you are busy processing data from the last call. If you don't poll for a long, the group coordinator might assume that you are dead and trigger a rebalance activity. You don't want that to happen, Right? Because you were not dead, you were computing.
2. The second risk is also related to rebalancing. The coordinator triggers a rebalance activity for some other reason while you are processing an extensive list of messages.

All cases with solution described HERE