01 December 2013

How to Install and Configure HAProxy on CentOS/RHEL 7/6/5

Written by Rahul K.

HAProxy is a very fast and reliable solution for high availability, load balancing, It supports TCP and HTTP-based applications. Now a days most of the websites need 99.999% uptime for their site, which are not possible with single server setup. Then we need some high availability environment which can easily manage with single server failure.

This article will help you to install HAProxy on CentOS, RHEL servers and will configure a Layer 4 Load Balancing (Transport Layer). Which will balance load and transfer requests to different-2 servers based on IP address and port numbers.

Step 1 – Install HAProxy

HAProxy package is available under default yum repository for CentOS, Redhat systems. Use the following yum package manager command to install HAProxy on your system.

# yum install haproxy

Step 2 – Configure HAProxy

Update your HAProxy configuration file /etc/haproxy/haproxy.cfg as per your requirement, You may also use below given configuration file as an example of setup and modify it.

# vim /etc/haproxy/haproxy.cfg

[ Update red mark values as per your network setup ]

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
        timeout server 86400000
        timeout connect 86400000
        timeout client 86400000
        timeout queue   1000s

# [HTTP Site Configuration]
listen  http_web 192.168.10.10:80
        mode http
        balance roundrobin  # Load Balancing algorithm
        option httpchk
        option forwardfor
        server server1 192.168.10.100:80 weight 1 maxconn 512 check
        server server2 192.168.10.101:80 weight 1 maxconn 512 check

# [HTTPS Site Configuration]
listen  https_web 192.168.10.10:443
        mode tcp
        balance source# Load Balancing algorithm
        reqadd X-Forwarded-Proto: http
        server server1 192.168.10.100:443 weight 1 maxconn 512 check
        server server2 192.168.10.101:443 weight 1 maxconn 512 check

Change the ips in configuration file as per your network setup. In HTTP Site Configuration section if any request on ip 192.168.10.10 on port 80, this will be redirected to port 80 of 192.168.10.100 or 192.168.10.101 servers. Similarly in HTTPS Site Configuration if any request on ip 192.168.10.10 on port 443, this will be redirected to port 443 of 192.168.10.100 or 192.168.10.101 servers.

You also need to make few changes in configuration file as per your system configuration.

nbproc <value> # Number of processing cores in your system.
mode <value> # ‘http’ for http site and ‘tcp’ for https site
balance <value> # Type of load balancing like ‘source’, ’roundrobin’ etc.

Step 3 – Start HAProxy Service

Start HAProxy service using following command, also configure it to auto start on system boot.

# service haproxy start
# chkconfig haproxy on

And You have done it.

Congratulation’s! you have successfully configured HAProxy load balancer. Read next article to enable haproxy stats and setup ACL in HAProxy.

For more configuration details check below url. http://haproxy.1wt.eu/download/1.4/doc/configuration.txt

Rahul K.

I, Rahul Kumar is the founder and chief editor of TecAdmin.net. I am Red Hat Certified Engineer (RHCE) and working as IT professional since 2009.

9 Comments

Allwyn Reply to Allwyn

August 10, 2015 at 11:01 am

Hi,
How to make ha proxy route the traffic if the URL has paths after ‘/’ ? My web app URL is like this http://abc.com:8080/xyz. In my front-end settings I have used ‘path_beg’ to identify ‘/xyz’ but couldn’t set something similar in the back-end settings. Any thoughts ?
Super Man Reply to Super

February 10, 2015 at 5:42 am

Can this solution be used to support failover for non-http processes? All we want to achieve is an automatic failover from host_a to host_b if there is a problem with host_a. A very simplistic failover. The app uses a network drive to store its configuration files ,etc. so the host_b can take over with minimal disruption (users can wait upto a minute or so , but the transition needs to be automatic). I was thinking of using a virtual IP address configured on both hosts and a simple script to start the app on host_b when host_a is down. Any ideas?

Thanks in Advance.
- Rahul Reply to Rahul
  
  April 7, 2015 at 3:52 am
  
  Hi,
  
  If you are thinking about that you add 2 hosts but only one host serve requests continuously and second host keep as spare. In any case first host goes down, then second take place of them.
  
  This you can do by adding host_a as active and host_b as backup. Configuration looks like below
  
  listen http_web 192.168.10.10:80
  mode http
  balance source
  option httpchk
  option forwardfor
  server host_a 192.168.10.100:80 weight 1 maxconn 512 check
  server host_b 192.168.10.101:80 weight 1 maxconn 512 check backup
  
  Also you can use this configuration for non http requests.
saudi Reply to saudi

January 1, 2015 at 9:28 am

easy to follow explanation. thanks
dhenyismail Reply to dhenyismail

July 29, 2014 at 7:44 am

how to configure haproxy explanation of this?

server server1 192.168.10.100:443 weight 1 maxconn 512 check
server server2 192.168.10.101:443 weight 1 maxconn 512 check

thanks..
Mathieu Reply to Mathieu

May 14, 2014 at 1:53 pm

HaProxy seems to be not available on EPEL for RHEL6/CentOS6.
- dbman Reply to dbman
  
  July 24, 2014 at 8:34 pm
  
  It is no longer on EPEL. haproxy was moved to the base load for RHEL/CentOS 6.4 and above. You will find it in the base repo, or on your DVD if you have 6.4 or later.
Harsh Reply to Harsh

October 18, 2013 at 11:04 am

Very nice blog, Simple and precise..
sustainabilitymarket.in Reply to sustainabilitymarket.in

July 3, 2013 at 7:13 pm

Whoa! This blog looks just like my old one!
It’s on a completely different topic but it has pretty much the same page layout and design. Outstanding choice of colors!