Using Haproxy + shadowsocks (ha + ss) to setup multi ss backend and load balance

*Install haproxy

> sudo apt-get install haproxy

*Configure haproxy

>vim /etc/haproxy/haproxy.cfg

global

    ulimit-n 51200

    log /dev/log local0

    log /dev/log local1 notice

    chroot /var/lib/haproxy

    pidfile /var/run/haproxy.pid

    user haproxy

    group haproxy

    daemon

defaults

    log global

    mode tcp

    option dontlognull

    timeout connect 5000 

    timeout client 50000

    timeout server 50000

frontend ss-in

    mode tcp 

    bind $Your_IP:8002

    default_backend shadowsocks

backend shadowsocks

    mode tcp 

    balance roundrobin

        server ss1 $Your_SS_IP1:$Your_SS_PORT1 maxconn 20480
        server ss2 $Your_SS_IP2:$Your_SS_PORT2 maxconn 20480

--The haproxy only allows the remote ss servers with the same password. As here haproxy is only providing the function like a load balancing switch. It's like a multi channel valve which does NOT provide any shadowsocks protocol level functions. Haproxy only foward the packages from ss-in to ss-out and ss-out to ss-in.
--The configuration above will setup ss1 and ss2 as the two channels to your remote shadowsocks server. And it will setup the frontend listen on the local port 8002 which acts like a real local ss server but actually load balanced remote servers ss1 and ss2.

*Restart haproxy

>sudo /etc/init.d/haproxy restart