It's a trade-off: C vs A. If you can't lose data, Kafka's current configuration is unacceptable. There's an open issue, but it isn't fixed yet, and this means

It's a trade-off: C vs A. If you can't lose data, Kafka's current configuration is unacceptable. There's an open issue, but it isn't fixed yet, and this means Kafka is (currently) unsuitable e.g. for use as a transaction log. Kafka is great if your data is lower value (e.g. web analytics). It's a pity, because it would be great to have an open source component for the Kafka architecture, but where data-loss is unacceptable. Hopefully this will be fixed in Kafka itself; I've also been working on something that is based around Raft.