During cluster peak, KAFKA NetworkProcessorAvgIdlePercent is lower than 0.2

[dong yu]

This is my problem
1.The request queue is always at 500
2.NetworkProcessorAvgIdlePercent is lower than 0.2


This is my BROKER configuration
num.io.threads=32
num.network.threads=64

How have I identified the cause and how to optimize my KAFKA cluster?
THKS。