Thank you for your thorough reply. I am sorry i don't have time to consider all aspects of it. But to me it seems like a problem around what optional means, a

Thank you for your thorough reply. I am sorry i don't have time to consider all aspects of it. But to me it seems like a problem around what optional means, and it has been very unstable, in particular in the transition between proto2 and proto3. Avro just seems like a more stable choice. Also back to my main point, that support for protobuf in Apache products is iffy.