Kafka failures when sending to a single topic:
- We can't connect to any brokers
- We connect to a broker but cluster metadata fetch fails
- Metadata doesn't know about topic
- Metadata has no leader for that partition we want to send to
- There is a leader for the partition but we can't connect to it
- There is a leader for the partition and we sent the request but we timedout or the connection broke (unclear if success)
- There is a leader for the partition and we sent the request but the broker returned an error
- There is a leader for the partition, required_acks > 1 and we sent the request but the leader didn't receive acks in time.