Network Processor Idle Drop Precedes Request Timeouts
criticalWhen network processor average idle percentage drops significantly, it indicates the broker is overwhelmed processing network I/O, leading to client-side request timeouts before requests reach handler threads.
Monitor kafka.network.SocketServer.NetworkProcessorAvgIdlePercent or kafka.net.processor.avg.idle.pct.rate dropping below 0.3 (30% idle). Cross-reference with kafka.request.produce.failed.rate and kafka.request.fetch.failed.rate to confirm client-side failures.
Increase num.network.threads to add network processor capacity. Verify network bandwidth is not saturated. Review client timeout configurations - increase request.timeout.ms if appropriate. Scale broker count horizontally to distribute network load. Check for inefficient client configurations causing excessive small requests.