HAProxy is a network software application that offers high availability, load balancing, and proxying for TCP and HTTP network applications. It is suited for high traffic and powers many websites. This article will show you how to install and setup HAProxy on Ubuntu 14.04.
Although HAProxy has several prominent features, this article focuses on how to setup HAProxy to “proxy” your web application.
Since Ubuntu 14.04 does not ship with HAProxy 1.5 (latest stable release at time of writing), we will have to use a PPA to be able to install it using
Next, update the system:
apt-get update apt-get dist-upgrade
Now install HAProxy with the following command:
apt-get install haproxy
If everything is successful, then you have finished installing HAProxy and can proceed to the next step.
The HA Proxy configuration file is split up into two sections – “global”, and “proxies”. One deals with process-wide configuration, while the other consists of default configuration, frontend, and backend sections.
With your favorite text editor, open
/etc/haproxy/haproxy.cfg and you will notice the predefined sections: “global” and “defaults”. The first thing that you may want to do is increase the
maxconn to a reasonable size, as this affects the connections that HAProxy allows. Too many connections may cause your web service to crash due to many requests. You will need to adjust the size to see what works for you. In the global section, add or change
maxconn to 3072.
In the default section, add the following lines under
option forwardfor option http-server-close
This will add
X-Forwarded-For headers to each request, as well as reduce the latency between HAProxy and to preserve client persistent connections.
Frontend and Backend
Commonly, the first thing when it comes to using is to setup a frontend to handle HTTP connections. Add the following:
frontend http-frontend bind public_ip:80 reqadd X-Forwarded-Proto:\ http default_backend wwwbackend
Note: Be sure to replace
public_ip with your domain or your public ip. Otherwise, this entire setup will not work.
After you have finished configuring the frontend, you can now add your backend by adding the following lines to the end of your configuration:
backend wwwbackend server 1-www private_ip_1:80 check server 2-www private_ip_2:80 check server 3-www private_ip_3:80 check
The backend configuration used here creates a connection named
private_ip_X:80 (Replace X with 1 – 3. and replace
private_ip_X with your private or public ip). This will allow you to load balance between each server set (assuming you have more than one server). The
check option makes the load balancer perform health checks on the server.
When you are done, save the configuration file, then restart HAProxy by running:
service haproxy restart
If everything is working, then you will be able to connect to
http://public_ip/ (replacing it with your AKLWEB Host VPS IP) and view your website.