Collision Resistant Hash Function: Setting Up HAProxy on CentOS

This post will go over installing and setting up HAProxy on CentOS. HAProxy is a load balancer, and in this case, will have a public ip of 1.1.1.1 with 10.0.0.0/8 as the private network load balancing http.

Step 1:
Install HAProxy. If you have not already done so, install the epel repository.

wget http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
rpm -ivh epel-release-6-8.noarch.rpm
yum install haproxy

The configuration file is stored in /etc/haproxy/haproxy.cfg. You may want to back this file up as it will be modified in the next step. You can also set up the service to start at boot:

chkconfig haproxy on

Step 2:
Set up the haproxy.cfg file. There are a number of configuration options for haproxy, most of which can be found here. The below configuration is how this system will be set up.

global
  maxconn 2000 # this system only has 512MB of memory
  daemon
  nbproc 1 # specify the number of processors to use
  log 127.0.0.1 local2
  user haproxy
  group haproxy
defaults
  log global
  mode http
  option httplog
  option dontlognull
  option http-server-close
  option forwardfor except 127.0.0.0/8
  option redispatch
  retries 3
  timeout http-request 10s
  timeout queue 1m
  timeout connect 10s
  timeout client 1m
  timeout server 1m
  timeout http-keep-alive 10s
  timeout check 10s
  maxconn 1900
listen webservice 0.0.0.0:80
  mode http
  status enable
  stats uri /haproxy?stats
  stats realm Private
  stats auth admin:password
  balance roundrobin
  option httpclose
  option forwardfor
  server server2 10.0.0.2 check
  server server3 10.0.0.3 check

Once the configuration is set up, start the service:

service haproxy start

Step 3:
Set up the backend servers defined in haproxy.cfg. In this example, just the apache test page is being used. Apache can be installed with a simple