get Kafka unconsumed messages count in Java

Question

We would like to know the messages count which are not yet consumed and acknowledge by Kafka Consumer for a given Kafka topic.

Is there any way we can get the count of Unconsumed Kafka messages from a given Topic (Topic is having 10 partitions) in Java ??

Answer 1

kafka consumers have a per-partition "records-lag" metric (introduced in kip-92). you can sum those metrics for all partitions of your topic, and get a figure for unconsumed messages