First, we deploy WordPress on two or more virtual machines.

Then, we will use HAProxy as a load balancer.

HAProxy(High Availability Proxy):- It is an open-source load balancer that can load balance any TCP service. It is particularly suited for HTTP load balancing as it supports session persistence and layer 7 processing.

Installing HAProxy

Install HAProxy on the machine that will serve as the load balancer.

apt-get install haproxy

To check the installation.

haproxy -v

Configuring HAProxy

Create a configuration file for HAProxy. This file will specify the behavior of the load balancer, including the addresses and ports of the backend servers it will be balancing traffic to. In the configuration file, define the frontend and backend sections.

sudo nano /etc/haproxy/haproxy.cfg

We'll get this in configure file by default.

global
    log /dev/log local0
    log /dev/log local1 notice
    chroot /var/lib/haproxy
    stats socket /run/haproxy/admin.sock mode 660 level admin         expose-fd lis>
    stats timeout 30s
    user haproxy
    group haproxy
    daemon

    # Default SSL material locations
    ca-base /etc/ssl/certs
    crt-base /etc/ssl/private
    # See: https://ssl-config.mozilla.org/#server=haproxy&server-version=2.>
    ssl-default-bind-ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128>
    ssl-default-bind-ciphersuites TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SH>
    ssl-default-bind-options ssl-min-ver TLSv1.2 no-tls-tickets

defaults
    log global
    mode http
    option httplog
    option dontlognull
    option redispatch
    timeout connect 5000
    timeout client 50000
    timeout server 50000
    errorfile 400 /etc/haproxy/errors/400.http
    errorfile 403 /etc/haproxy/errors/403.http
    errorfile 408 /etc/haproxy/errors/408.http
    errorfile 500 /etc/haproxy/errors/500.http
    errorfile 502 /etc/haproxy/errors/502.http
    errorfile 503 /etc/haproxy/errors/503.http
    errorfile 504 /etc/haproxy/errors/504.http

You can modify this if necessary and make changes, or leave it as-is.

The frontend section defines the IP address and port that the load balancer will listen on, while the backend section defines the addresses and ports of the backend servers.

frontend web-frontend
    bind *:80:
    mode http
    default_backend web-backend

In the backend section, configure the load balancing algorithm to be used. HAProxy supports several algorithms, including round-robin, least-connections, and IP-hash.

backend web-backend
    balance roundrobin
    server web1 192.168.1.13:80 check
    server web2 192.168.1.14:80 check

The server directive declares a backend server, the syntax is:

server <name> <address>[:port] [param*]

To use HAProxy's statistics page to monitor the real-time statistics of the load balancer.

listen stats
    bind 192.168.1.9:8030
    mode http
    stats enable
    stats hide-version
    stats refresh 30s
    stats show-node
    stats auth admin:password
    stats uri /stats

HYProxy stats can be accessed on the machine's IP and port specified in the configuration file above.