HA Proxy stands for High Availability Proxy written on C. It is a free and open source TCP/HTTP load balancer and proxy solution for TCP and HTTP based applications. HA Proxy allows you to balance incoming TCP / HTTP Traffic by distributing load across backend server using different criteria.
The use of HA Proxy is to provide fault tolerance and high availability in case when one node is getting too many concurrent requests. It is used by most famous web sites like GitHub, Stack Overflow and Tumbler.
HA Proxy allows an application to restart automatically or reroute work to another server in the event of a failure. HA Proxy is a powerful, high power, reliable and secure load balancer.
In his tutorial we will install and configure HA Proxy on CentOS 8.
Install HA Proxy:
yum -y install haproxy
![](http://unixcop.com/wp-content/uploads/2021/09/image-146.png)
Configure HA Proxy:
Please note that the following configuration is for Application that use TCP connection to connect to the destination machine / Application.
Ha proxy Configuration involves 4 steps:
- global settings: First, we use to set process-wide parameters.
- defaults: Secondly, we defaults use to set default parameters for all other sections.
- frontend: In this section we define how we access HA Proxy externally to enable access to the backend.
- backend: Used to define a set of servers to which the proxy will connect to forward incoming connections.
Now, create a directory named run in /etc/haproxy for stats socket.
mkdir /etc/haproxy/run
Open HA proxy configuration file with the following command:
nano /etc/haproxy/haprxoy.conf
Remove the default configuration present in file.
Now, add the following configuration:
global
log /dev/log local0
log /dev/log local1 notice
chroot /var/lib/haproxy
stats socket /etc/haproxy/run/admin.sock mode 660 level admin
stats timeout 30s
user haproxy
group haproxy
daemon
defaults
log global
option dontlognull
option tcplog
mode tcp
timeout connect 5000
timeout client 50000
timeout server 50000
listen stats
bind 192.168.7.38:3000
mode http
maxconn 10
timeout queue 300s
stats enable
stats refresh 10s
stats show-node
stats auth haproxyadmin:haproxyadmin
stats uri /haproxy
frontend server_front
bind *:9909
default_backend server_back
backend server_back
balance roundrobin
server S1 192.168.189.129:9909 check
server S2 192.168.189.130:9909 check
Please note that the above configuration is for TCP connection or Application where TCP connection with server is required. You can also do the configuration for HTTP applications by replacing tcp with http in above configuration.
Start and Enable HA Proxy:
systemctl start haproxy.service
systemctl enable haproxy.service
systemctl status haproxy.service
![](http://unixcop.com/wp-content/uploads/2021/09/image-148.png)
Open HA Proxy url to see the connections statistics.
![](http://unixcop.com/wp-content/uploads/2021/09/image-149.png)