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Kafka Is Fun

Consumer Deep Dive

Consumer groups, rebalancing protocols, offset management, and consumer lag mastery.

0 of 5 lessons complete

  1. 1Consumer Groups & Partition AssignmentA consumer group is a set of consumers that jointly consume a topic: each partition is consumed by exactly one consumer …
  2. 2The Rebalance ProtocolWhen group membership changes, the group coordinator triggers a rebalance. In the classic protocol the coordinator selec…
  3. 3Offset ManagementConsumers record their progress as committed offsets, which the group coordinator stores in an internal Kafka topic, __c…
  4. 4Consumer Lag & MonitoringConsumer lag is how far a group is behind the end of a partition. kafka-consumer-groups.sh --describe shows CURRENT-OFFS…
  5. 5Cooperative & Static MembershipStatic membership (group.instance.id, KIP-345) lets a consumer rejoin with its identity after a restart without a full r…

Knowledge check

Q1.What is consumer lag?

Q2.What does auto.offset.reset=earliest do for a group with no committed offset?

Q3.Why is group.instance.id useful in Kubernetes?