KIP-188 — Add new metrics to support health checks

Accepted Kafka 1.0 MetricsBroker

Adds broker-side error rate metrics per request type and per error code, and a `NetworkProcessorAvgIdlePercent` metric per network thread, to expose health signals useful for automated health checks. Without error rate metrics, the only way to detect systematic request failures is by examining consumer/producer logs or observing indirect symptoms like lag.

Protocol Impact

Fetch

Details