kafka-lag-exporter VS java-kafka-client

- https://github.com/prometheus/jmx_exporter - https://github.com/lightbend/kafka-lag-exporter (Export Kafka Topics Lag Metrics) - https://github.com/danielqsj/kafka_exporter (Export Kafka Metrics) - https://github.com/obsidiandynamics/kafdrop (Topic Administration tool - create/edit/delete topics & view messages)

Kafka Lag Exporter is not part of the Apache Kafka project nor the Confluent Platform. It’s an open-source project under Apache-2.0 License to export Consumer Lag with reporters like Prometheus, Graphite, or InfluxDB. Kafka Lag Exporter enables to monitor Consumer Lag but it also allows to estimate the Time Lag. This metric shows how far a Consumer group is behind the last produced record in terms of time. It shows the actual latency of a consumer application. For more information about this estimation, you can read the chapter of the documentation Estimate Consumer Group Time Lag

This is particularly useful if you use Apache Kafka in a microservices architecture and you want to add tracing supervision. For example, using OpenTracing you can take a look at opentracing-contrib/java-kafka-client that provides TracingProducerInterceptor and TracingConsumerInterceptor. Those interceptors inject and retrieve span context from record headers.