Load balancing is a key and Major part of IT infrastructure and this is because the High availability and efficient performance of webservers are very important. The purpose of load balancing is to prevent a server from being overloaded and maintain healthy servers by balancing incoming requests. Please see Setup Public Load Balancer in Azure, How to create a load balancer for Azure Stack Hub, and How to Configure Network Load Balancing In Windows Server
A Load Balancer is available, reliable, and highly scalable web application. Furthermore, In this tutorial, I will deploy one Haproxy server and 2 backend servers in a Lab environment. However, in a subsequent post, I will show how to configure, deploy and troubleshoot an ELB on cloud platforms.
NOTE: All deployments are done on CentOS 8.
Also, see Installing and configuring SimpleSAMLphp [Part 2], and How to create an EC2 Instance.
Installing and configuring HAproxy
Yum -y install Haproxy
NOTE: Back up the default config file, should anything go wrong, we can revert.
mv /etc/haproxy/haproxy.cfg /etc/haproxy/haproxy.cfg-bak
create a new haproxy config file and paste the following
vim /etc/haproxy/haproxy.cfg
#———————————————————————globallog 127.0.0.1 local2chroot /var/lib/haproxypidfile /var/run/haproxy.pidmaxconn 4000user haproxygroup haproxydaemon# turn on stats unix socketstats socket /var/lib/haproxy/stats# utilize system-wide crypto-policiesssl-default-bind-ciphers PROFILE=SYSTEMssl-default-server-ciphers PROFILE=SYSTEM#———————————————————————defaultsmode httplog globaloption httplogoption dontlognulloption http-server-closeoption forwardfor except 127.0.0.0/8option redispatchretries 3timeout http-request 10stimeout queue 1mtimeout connect 10stimeout client 1mtimeout server 1mtimeout http-keep-alive 10stimeout check 10smaxconn 3000# main frontend which proxys to the backendsfrontend haproxy_balancer # define the name of the frontend.bind 192.168.0.10:80 # IP address of HAProxy serveroption http-server-closeoption forwardforstats uri /haproxy?stats # Specify the HAProxy status page.default_backend webservers# round robin balancing between the various backendsbackend webservers # Specify a name for identifying an applicationmode httpbalance roundrobin # defines the roundrobin load balancer scheduling algorithmoption httpchk HEAD / HTTP/1.1\r\nHost:\ localhostserver nginx-web1 192.168.0.11:80 check # IP address of the first backend serverserver nginx-web2 192.168.0.12:80 check # IP address of the second backend server
NOTE: Kindly change the Mode and the server IPs as specified based on your configurations
Test the configuration for errors
haproxy -c -f /etc/haproxy/haproxy.cfg
Start and Enable the Haproxy service
Checking the HAproxy status
Open the Web Url of your front end server
Check Statistics and status of Haproxy
Now you can keep adding backend servers.
NOTE: When deploying a load balancer from scratch, ensure that backend servers have Nginx installed. Additionally, confirm the availability and firewall permissions for the backend port.
I hope you found this blog post on Deploying a load balancer from scratch and adding backend servers helpful. Please let me know in the comment session if you have any questions.
