Light Kafka exporter

Quick CLI util and Prometheus exporter for checking your Kafka: The number of records that should be flowing, are they actually flowing?

The non-quick way

The proper way of going on about this is to

• Get the prometheus/jmx_exporter
• Acquire a jmx_exporter configuration file from somewhere
  • the "official" one doesn't work that well
• Pass the jmx_exporter as a -javaagent via KAFKA_JMX_OPTS to kafka-server-start.sh
• Target prometheus to scrape the agent
• Hope that you can now query badly named metrics like kafka_…_brokertopicmetrics_messagesinpersec (Which is not per sec. You need to irate it.)

Need to know right now? Have fun restarting your brokers.

The quick way

This repeatedly queries the high watermarks of all topics via Kafka's normal listening ports and calculates a flow rate. Clone and run as

cargo run -- -b localhost:9092

If you're looking for prettier output, try totop.