1. 统计连接状态
netstat -n | awk '/^tcp/ {++State[$NF]} END {for(s in State) print s, State[s]}' CLOSE_WAIT 3 ESTABLISHED 28 SYN_SENT 6
https://www.infoq.cn/article/linux-networking-performance-analytics
https://blog.csdn.net/shixin_0125/article/details/78686152