Consumer Group

What is a consumer group?

A consumer group is a group of consumers, usually combine multiple clients the same characteristics and/or replicas/workers of the same application/client.
The added layer of a consumer group enables to control ordering and avoid duplicate processing of messages within the same type of consumers.
Each message will be delivered in parallel to all consumer groups.
Each consumer group gets the same messages
Inside the consumer group, a message will be delivered to only one consumer
There is no consumer without a consumer group.