No label/attribute for some Kafka consumer metrics exposed by Spring boot actuator and micrometer

Question

I've configured Spring boot actuator and micrometer for exposing Kafka consumer metrics. Some of the Kafka metrics don't have 'topic' label. For example,

kafka_consumer_records_consumed_total_records_total{client_id="consumer-1",topic="topic1",} 0.0
kafka_consumer_records_consumed_total_records_total{client_id="consumer-2",topic="topic2",} 0.0
kafka_consumer_records_consumed_total_records_total{client_id="consumer-3",topic="topic3",} 0.0

kafka_consumer_commit_latency_max_seconds{client_id="consumer-1",} 0.013
kafka_consumer_commit_latency_max_seconds{client_id="consumer-2",} 0.013
kafka_consumer_commit_latency_max_seconds{client_id="consumer-3",} 0.013

My question is

1. Is there any configuration required to show 'topic' label for metric kafka_consumer_commit_latency_max_seconds?

2. I noticed that client_id="consumer-1" is same for topic="topic1" even after application restart. Can I rely on client_id to be always point to the specific topic?

Answer 1

Some metrics are global for the Consumer; some are specific to a topic and some are specific to a topic/partition.

The client.id is fixed; when generated by the kafka-clients, there is no guarantee you will always get the same one for a topic, but you can set a specific ConsumerConfig.CLIENT_ID for each consumer.