003. Kafka Theory. Topic Replication - MarkHuntDev/my-kafka-exercises GitHub Wiki

Topic replication factor

  • Topics should have a replication factor > 1 (usually between 2 and 3)
    • Replication factor equal to 3 is the gold standard
  • This way if a broker is down, another broker can serve the data
  • Example: Topic-A with 2 partitions and replication factor of 2
  • Example: we lost Broker 102
  • Result: Broker 101 and 103 can still serve the data

Concept of a Leader for a Partition

  • At any time only ONE broker can be a leader for a given partition
  • Only that leader can receive and serve data for a partition
  • The other brokers will synchronize the data
  • Therefore each partition has one leader and multiple ISR (in-sync replica)