Kafka Guarantees
- Messages are appended to a topic-partition in the order they are sent
- Consumers read messages in the order stored in a topic-partition
- With a replication factor of N, producers and consumers can tolerate upto N-1 brokers being down
- This is why a replicaton factor of 3 is a good idea:
- Allows for one broker to be taken down for maintenance
- Allows for another broker to be taken down unexpectedly
- As long as the number of partitions remains constant for a topic (no new partitions), the same key will always go to the same partition