Practical Labs

11 structured exercises that run against the cluster simulator. Each lab has an objective, step-by-step instructions with expected results, validation criteria and the interview angle.

1. 1Leader Failover RecoverySee what happens to a producer when the leader of the partition it writes to stops.Beginner5 min6 steps
2. 2ISR Shrink Under Follower LagMake a follower fall behind and watch it leave the ISR, then see what that does to acks=all writes.Intermediate7 min7 steps
3. 3Min ISR Block (NOT_ENOUGH_REPLICAS)See min.insync.replicas refuse an acks=all write because too few replicas are in sync.Intermediate5 min5 steps
4. 4Network PartitionCut brokers off from the cluster while their processes keep running, and watch the cluster carry on without them.Advanced8 min7 steps
5. 5Consumer Group RebalanceWatch partition assignments change when consumers join or leave a group.Beginner6 min6 steps
6. 6Producer acks Comparison (0 vs 1 vs all)See what the producer waits for with acks=0, acks=1 and acks=all, and when acks=all refuses a write.Beginner5 min5 steps
7. 7Trace a Message Through the PipelineFollow one message through the producer pipeline and see which stages acks=0 and a stale leader change.Beginner4 min4 steps
8. 8Replica Recovery After Extended FailureSee a broker fall behind while it is offline and catch up before it rejoins the ISR.Advanced8 min4 steps
9. 9Understanding HWM vs LEORead the log end offset and the high watermark on each partition and see what they mean for consumers.Intermediate5 min4 steps
10. 10Unclean Leader Election (Data Loss Demonstration)See what unclean leader election trades: availability for the chance of losing data.Advanced6 min5 steps
11. 11Triage a Dead Letter Queue FloodPractise sampling and classifying a DLQ flood instead of reacting to it record by record.Intermediate8 min5 steps