Kafka Group ID: Understanding Consumer Groups in Apache Kafka

In Apache Kafka, a group ID is a string that is used to uniquely identify a group of consumers within a Kafka cluster. Each consumer within a group must have the same group ID in order to be part of that group. The group ID is used for coordinating the consumption of messages from Kafka topics. \n\nWhen a consumer joins a group with a specific group ID, it is assigned a set of partitions from the subscribed topics. Each partition is then assigned to only one consumer within the group, ensuring that each message is consumed by only one consumer in the group. This allows for parallel processing of messages within a consumer group. \n\nThe group ID is important for managing the state and offset of each consumer within the group, as it helps coordinate the processing of messages and ensures fault-tolerance and load balancing in a Kafka cluster.