How to intall and configure Haproxy on Centos

1. Install Haproxy 
   CentOS/RHEL 5 , 32 bit:
   # rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm 
   CentOS/RHEL 5 , 64 bit:
   # rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm 
   CentOS/RHEL 6 , 32 bit:
   # rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm 
   CentOS/RHEL 6 , 64 bit:
   # rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
   yum -y install haproxy
2. Configure Haproxy
   vi /etc/haproxy/haproxy.cfg
   

   global
           log 127.0.0.1   local0
           log 127.0.0.1   local1 debug
           maxconn   45000 # Total Max Connections.
           daemon
           nbproc      1 # Number of processing cores. 
   defaults
           log     global
           mode    http
           option  httplog
           option  dontlognull
           retries 3
           option redispatch
           maxconn 20000
           timeout server 86400000
           timeout connect 86400000
           timeout client 86400000
           timeout queue   1000s
           
   # [HTTP Site Configuration]
   listen  http_web 10.10.0.112:80
           mode http
           balance roundrobin  # Load Balancing algorithm
           option httpchk
           option forwardfor
           server server1 23.253.48.253:80 weight 1 maxconn 512 check
           server server2 208.43.40.162:80 weight 1 maxconn 512 check
   
   
   # [Change HAProxy Stats URL]
   listen  stats   10.10.0.112:1936
           mode            http
           log             global
           balance roundrobin
   
           maxconn 10
   
           timeout server 86400000
           timeout connect 86400000
           timeout client 86400000
           timeout queue   1000s
   
           stats enable
           stats hide-version
           stats refresh 30s
           stats show-node
           stats realm Haproxy Statistics
           stats auth admin:password
           stats uri  /ha-stats

   开启防火墙 1936 端口
3. 重启相关服务
   service iptables restart 
   service haproxy restart
   chkconfig haproxy on
4. 后台查看网站：
   http://10.10.0.112:1936/ha-stats  or  http://10.10.0.112:1936/stats
5. 参考链接：
   http://tecadmin.net/install-and-configure-haproxy-on-centos/