Experiments with Kafka's head-of-line blocking (2023)
4 months ago
- #Kafka
- #Performance
- #Message Queues
- Kafka is a distributed message system with high throughput but can suffer from head-of-line blocking when used as a job queue.
- Kafka messages are sent to topics with partitions, and consumers in a group read from assigned partitions, leading to potential idle consumers if one is slow.
- Beanstalkd serves jobs to available consumers without head-of-line blocking, as jobs are reserved from tubes by the first available consumer.
- An experiment compared Kafka and Beanstalkd with five consumers each, where Kafka took twice as long to process jobs due to head-of-line blocking.
- The experiment showed that Beanstalkd processed 96 out of 100 jobs in less than a second, while Kafka had periods of inactivity due to slow consumers.