Load Balancing is a method in computer networking to distribute the work load between multiple servers that are setup in a cluster, typically as a web server or database server. The load balancer disperses traffic and user requests efficiently among the servers in the network, thereby increasing the web server’s scalability and database server’s performance.
This methodology is implemented to achieve maximum availability of a site or database by not letting an individual server become overburdened with the traffic. Major websites like Google, Facebook, and Amazon strives to maintain 100% uptime by placing thousands of servers in cluster. Load balancing methodology is often used to implement failover and redundancy.
Architecture of a Load Balancing Server:
1) A Load Balancing Server architecture consists of at least 2 or more web servers with similar configurations and 2 database servers which are located behind the load balancer/master server.
2) Each web server is connected with an Internal LAN and has a public IP assigned. The Load balancing routing rules are implemented on the Master Server/ Load Balancer and a firewall is configured with rules to permit web traffic to the web server through the load balancer/master server.
3) The Master Server/ Load Balancer will then disperse the traffic equally on each of the web servers which will divert the SQL queries on to the database server. In order to make the database server highly available, a real-time mirroring solution is implemented on the two database servers using RSync and FAM modules.
4) A FAM module monitors the file system and if there is any change on the server, it is reflected on the second database server by Rsync in real-time. Thus, if one of the database server is down due to failure or maintenance, another database server immediately comes into the picture within a few seconds and starts providing service.
A Load Balancing Server is the best solution for redundancy and fail-over, delivering the highest level of reliability and stability. For complete Load Balancing Solution, take a look at Dedicated Servers offered by Tier.Net.