Hi all, I have just created KIP-98 to enhance Kafka with exactly once delivery semantics:
*https://cwiki.apache.org/confluence/display/KAFKA/KIP-98+-+Exactly+Once+Delivery+and+Transactional+Messaging <https://cwiki.apache.org/confluence/display/KAFKA/KIP-98+-+Exactly+Once+Delivery+and+Transactional+Messaging>* This KIP adds a transactional messaging mechanism along with an idempotent producer implementation to make sure that 1) duplicated messages sent from the same identified producer can be detected on the broker side, and 2) a group of messages sent within a transaction will atomically be either reflected and fetchable to consumers or not as a whole. The above wiki page provides a high-level view of the proposed changes as well as summarized guarantees. Initial draft of the detailed implementation design is described in this Google doc: https://docs.google.com/document/d/11Jqy_GjUGtdXJK94XGsEIK7CP1SnQGdp2eF 0wSw9ra8 We would love to hear your comments and suggestions. Thanks, -- Guozhang
