Kafka Internals: FAQs
A quick cheat sheet for the basic questions new comers to Apache Kafka often face,.
Join the DZone community and get the full member experience.Join For Free
Is there chance that a consumer can read from more than one partition in a topic?
Yes, of course. If the number of consumers is less than the number of partitions in the topic.
What is the optimal number of consumers in a group for a topic?
As many as the number of partitions.
Is there a chance for a consumer to be idle?
Yes, if the number of live consumers in a group is larger than the number of partitions. These idle consumers will be leveraged when a consumer crashes.
Does the Kafka broker retain messages until they are consumed by all subscribers?
No, it is the consumer's responsibility to consume messages when they are available in a topic.
It is analogous to subscribing and watching content from satellite channel. The subscriber should tune to the channel while the content is being played to watch.
If you want to take a closer look at Apache Kafka, check out my previous two articles:
Opinions expressed by DZone contributors are their own.