vanish(squid) + HAProxy + nginx + memcached(redis)

1. Load-balance then cache

                                                +-- Cache server #1 (varnish) -- App server #1

                                             /

Load Balancer (haproxy)-+---- Cache server #2 (varnish) -- App server #2

                                             \

                                                +-- Cache server #3 (varnish) -- App server #3

2. Cache then load-balance

                                                        +-- App server #1

                                                      /

Cache Server (varnish) --- Load Balancer (haproxy) --+---- App server #2

                                                      \

                                                         +-- App server #3

I. stunnel -> vanish -> HAProxy -> nginx -> nodeJS -> memcached(redis)

II. nginx (for HTTP compression) --> Varnish cache (for caching) --> HTTP level load balancer (HAProxy, or nginx, or the Varnish built-in) --> webservers.

Apache Traffic Server/Squid/Vanish + HAProxy + Nginx + memcached(Redis)

Reference:

http://serverfault.com/questions/204025/ordering-1-nginx-2-varnish-3-haproxy-4-webserver

http://yaozb.blog.51cto.com/2762349/793875

http://stackoverflow.com/questions/15448196/haproxy-in-front-of-varnish-or-the-other-way-round

http://blog.exceliance.fr/2012/08/25/haproxy-varnish-and-the-single-hostname-website/

http://serverfault.com/questions/51691/need-haproxy-varnish-nginx-setup-suggestions

https://www.exratione.com/2012/08/websockets-over-ssl-stunnel-varnish-nginx-nodejs/