What is the generic unique identifier that can be used for a message received from a consumer?

• A. Key
• B. Topic + Offset
• C. Partition + Offset
• D. Topic + Partition + Offset

Answer: (D)

A message in Kafka is identified by three pieces: the topic it belongs to, the partition it resides in, and the offset within that partition. The topic gives the stream, the partition points to the specific shard, and the offset marks the position inside that shard. Taken together, topic, partition, and offset uniquely identify that exact record across the whole Kafka cluster. The message key isn’t a global identifier; it’s used for routing and log compaction, and many messages can share the same key. Offsets are only unique within a partition, so topic+offset isn’t enough, and partition+offset lacks the topic context. Hence, the full combination of topic, partition, and offset serves as the generic unique identifier.