Hi all, I have created KIP-253: Support in-order message delivery with partition expansion. See https://cwiki.apache.org/confluence/display/KAFKA/KIP-253%3A+Support+in-order+message+delivery+with+partition+expansion .
This KIP provides a way to allow messages of the same key from the same producer to be consumed in the same order they are produced even if we expand partition of the topic. Thanks, Dong