Beginner4 min
Trace a Message Through the Pipeline
Follow one message through the producer pipeline and see which stages acks=0 and a stale leader change.
A write touches several parts of Kafka: the producer finds the cluster and the partition's leader through a metadata request, sends a produce request to the leader, followers fetch from the leader to replicate, and the consumer's fetch and offset commit come afterwards. The Producer tab lays this out as a ten-step flow; the stage names are the simulator's, and the real requests are Metadata, Produce, Fetch and OffsetCommit.
The steps use the simulator and name the control to use. The outcomes they describe are what the simulator models; the sources below are what Apache documents.
Steps
0 of 4 steps completed
Verification
You can name the stages of a write in order and say which ones a leader change repeats.
The interview angle
Name the stages in order: metadata, produce to the leader, replication by follower fetches, the acknowledgement that acks selects, and then the consumer's fetch and offset commit.
Sources
- Protocol and error codes (4.2 documentation) (opens in a new tab)
- Design (4.2 documentation) (opens in a new tab)
- Producer configs (4.2 documentation) (opens in a new tab)
Checked against Kafka 4.2 documentation on 11 October 2026. Draft: not yet reviewed by a Kafka specialist, and releases move on, so confirm against the current documentation before you act on it.