Kafka replica particiones en múltiples brokers para durabilidad y disponibilidad — cada partición tiene un líder y réplicas seguidoras. Si un broker falla, una seguidora toma el control. Entender la replicación es clave para la tolerancia a fallos de Kafka.
Por qué es importante
Each PARTITION is replicated across multiple brokers (REPLICATION FACTOR copies, e.g. 3):
→ LEADER replica → handles all reads and writes for the partition
→ FOLLOWER replicas → copy (replicate) the leader's data, staying in sync
→ producers/consumers interact with the LEADER; followers are backups
→ if the leader's broker FAILS → a follower is promoted to leader (failover) → no data loss,
continued availability
