Hello! A customer upgrading from Kafka < 2.8 to the future release 3.6 and wanting to enable tiered storage would have to take responsibility for ensuring that all segments lacking a producer snapshot file have expired and are deleted before enabling the feature.
In our experience customers are not aware of this limitation and expect to be able to enable the feature as soon as their upgrade is complete. If they do this today, however, this results in NPEs. As such, one could argue this is a blocker for 3.6 due to the non-direct upgrade path from versions < 2.8. I would like to start a discussion on KIP-952: Regenerate segment-aligned producer snapshots when upgrading to a Kafka version supporting Tiered Storage (https://cwiki.apache.org/confluence/x/dIuzDw) which aims to solve this issue. Best, Christo
