Consumer groups and offsets
On This Lesson 4 topics
This lesson is planned. The outline below lists the topics it will cover. The full lesson has not been published yet.
In this lesson
explain how consumers share work and track position.
Planned topics
- A consumer group shares a topic's partitions; each partition goes to one member. Different groups each get all records.
- Offsets record the group's progress per partition, stored in the internal
__consumer_offsetstopic. - Commit after processing for at-least-once; commit before processing risks loss.
- Rebalancing reassigns partitions when members join, leave, or time out; processing pauses briefly.
- More consumers than partitions leaves some idle.
- Tune
max.poll.interval.msso slow processing does not trigger rebalances.
Draft outline details
Demonstration
group inventory with 2 consumers over 3 partitions, plus group payments reading the same topic.
Check your understanding
What happens if a group has more consumers than partitions?
Show answer
Extra consumers stay idle.
Practice
Apply this lesson with the module's lab, exercises and quiz.
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