https://unix.stackexchange.com/questions/12985/how-to-check-rx-ring-max-backlog-and-max-syn-backlog-size

Jason Cook - Tuning TCP for the Web - Fastly
https://vimeo.com/70369211
http://cdn.oreillystatic.com/en/assets/1/event/94/Tuning%20TCP%20For%20The%20Web%20Presentation.pdf
https://www.youtube.com/watch?v=gfYYggNkM20

https://wiki.mikejung.biz/Sysctl_tweaks
https://wiki.mikejung.biz/Apache

https://wwwx.cs.unc.edu/~sparkst/howto/network_tuning.php

https://medium.com/@pawilon/tuning-your-linux-kernel-and-haproxy-instance-for-high-loads-1a2105ea553e

https://gist.github.com/kfox/1942782

http://www.philchen.com/2015/10/28/how-to-performance-tune-ubuntu-14-04-lts-trusty-in-aws-ec2

https://fasterdata.es.net/assets/Papers-and-Publications/100G-Tuning-TechEx2016.tierney.pdf
For kernel 4.9+
sysctl -w net.core.default_qdisc=fq
sysctl -w net.ipv4.tcp_congestion_control=bbr