Kafka Internals — the replicated log — pick a scenario
0/3 donePick one and press Start, then click Next › to step through it.
Watch forThe new amber cell on the leader turning green only once both followers copy it, as the high-water mark line steps forward.
More about this scenario
You'll learnWhy a record isn't readable the instant the leader has it — it waits until every in-sync replica does.
How it runsThe leader appends at the next offset, each follower fetches and appends it, then the high-water mark advances to cover it.