Producers write messages to topics. They choose which partition using a key hash (consistent) or round-robin (no key). The acks setting controls durability: acks=0 (no confirm), acks=1 (leader confirm), acks=all (all ISR confirm). Consumers read from partitions by tracking their own offsets. A Consumer Group distributes partition assignments across members — each partition goes to exactly one consumer in the group.
Key configuration
acks=all — strongest durability
enable.idempotence=true — exactly-once producer semantics
auto.offset.reset=earliest|latest — where to start reading