Reduce TIME_WAIT

see time wait number

netstat -nat | awk '{print $6}' | sort | uniq -c | sort -n


vi  /etc/sysctl.conf

# Decrease TIME_WAIT seconds
net.ipv4.tcp_fin_timeout = 30

# Recycle and Reuse TIME_WAIT sockets
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1

sysctl -p

https://www.linux.org/threads/reduce-your-apache-time_wait-connections.4505/