Apache Kafka Kafka Producers & Consumers 3

Question 1

What is a 'consumer lag' in Kafka?

Accepted Answer

The difference between the latest produced offset and the consumer's current offset

Answer

Consumer lag measures how far behind a consumer group is relative to the latest messages produced in a partition.

Question 2

What does the `fetch.min.bytes` consumer configuration control?

Accepted Answer

Minimum data the broker returns in a fetch response before sending

Answer

fetch.min.bytes tells the broker to wait until at least that many bytes are available before responding to a fetch request, reducing round trips.

Question 3

Which of the following accurately describes a 'sticky partitioner' for producers?

Accepted Answer

It sends all batched messages to the same partition until the batch is full or linger.ms expires

Answer

The sticky partitioner batches records to a single partition until the batch is full or linger.ms fires, then switches, reducing the number of small batches.

Question 4

When using `assign()` instead of `subscribe()`, what is the consumer responsible for?

Accepted Answer

Manually managing partition assignment without group coordinator involvement

Answer

assign() gives the consumer direct control over which partitions it reads, bypassing the group coordinator and rebalance protocol entirely.

Question 5

What type of serializer is required when the producer message key is a String?

Accepted Answer

org.apache.kafka.common.serialization.StringSerializer

Answer

StringSerializer converts Java String keys/values to bytes, and is the standard serializer when working with string-typed keys.

Apache Kafka Practice Test

Apache Kafka Practice Test

Apache Kafka Kafka Producers & Consumers 3