How does Kafka behave with three partitions and four consumers in a group?

In Kafka, when there are 3 partitions and 4 consumers in a single group, the following occurs:

• Each partition can only be assigned to one consumer within the group.
• Since there are fewer partitions than consumers, one consumer will be left without an assigned partition and, consequently, without data to read.
• Therefore, 3 consumers will read data from 3 partitions, and the 4th will be idle.

This behavior ensures that each partition is read by only one consumer in the group, guaranteeing message order for each partition.