Apache Kafka Kafka Topics & Partitions 2

Question 1

What is a Kafka 'leader' partition?

Accepted Answer

The single replica that handles all reads and writes for a partition

Answer

Each partition has exactly one leader replica that handles all producer writes and (by default) consumer reads; followers replicate from it.

Question 2

What does 'log compaction' do in a Kafka topic?

Accepted Answer

Retains only the latest message for each key, removing older duplicates

Answer

Log compaction ensures that for each key, only the most recent message value is retained, acting like an upsert store for change-data-capture use cases.

Question 3

What is the purpose of the `__consumer_offsets` internal topic in Kafka?

Accepted Answer

Stores committed consumer group offsets so consumers can resume after restart

Answer

__consumer_offsets is an internal Kafka topic that durably stores the committed offsets for all consumer groups.

Question 4

What is an ISR (In-Sync Replica) set?

Accepted Answer

The set of replicas that are fully caught up with the leader's log

Answer

The ISR is the subset of a partition's replicas that have replicated all messages up to a configurable threshold and are considered 'caught up' with the leader.

Question 5

What command lists all topics in a Kafka cluster?

Accepted Answer

kafka-topics.sh --bootstrap-server <host> --list

Answer

kafka-topics.sh --list with --bootstrap-server connects to the cluster and lists all existing topic names.

Apache Kafka Practice Test

Apache Kafka Practice Test

Apache Kafka Kafka Topics & Partitions 2