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

The oldest replica across brokers

Answer

The replica with the highest offset

Answer

The broker that manages ZooKeeper metadata

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

Compresses log segments using gzip

Answer

Merges multiple segments into one

Answer

Removes all messages older than retention.ms

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

Logs producer errors

Answer

Tracks broker health metrics

Answer

Stores admin ACL configurations

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

All replicas regardless of replication lag

Answer

Only the leader replica

Answer

Replicas assigned to the controller broker

Question 5

What command lists all topics in a Kafka cluster?

Accepted Answer

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

Answer

kafka-topics.sh --zookeeper <host> --describe

Answer

kafka-configs.sh --list-topics

Answer

kafka-admin.sh --list

Question 6

What is the impact of increasing the number of partitions on a topic that already has consumers?

Accepted Answer

It triggers a consumer group rebalance as partitions are redistributed

Answer

Consumers are automatically updated with no interruption

Answer

It only affects new consumer groups

Answer

Partition increase requires topic deletion and recreation