How have you worked with Kafka? Have you tuned partitions or configurations? What happens if consumers are fewer than partitions?

Working with Kafka typically involves configuring partitions and settings for optimal performance and reliability.

• Partition Tuning:

  • The number of partitions affects consumption parallelism: more partitions — higher parallelism.
  • When increasing partitions, load balancing and message order should be considered.

• Configurations:

  • Setting replication.factor for fault tolerance.
  • Consumer parameters fetch.min.bytes, fetch.max.wait.ms to optimize latency and throughput.
  • Producer setting acks for balancing speed and reliability.

If the number of consumers is less than the number of partitions, some consumers will handle multiple partitions, which is normal. However, if there are more consumers than partitions, some consumers will be idle, as a partition cannot be split among multiple consumers in the same group.

Example: if a topic has 10 partitions and 3 consumers in a group, each consumer will read approximately 3-4 partitions.