In the realm of system design, load balancing is a critical component that ensures high availability and reliability of applications. One effective method of load balancing is DNS-based load balancing. This article will explore how DNS-based load balancing works, its advantages, and its implementation.
DNS-based load balancing is a technique that uses the Domain Name System (DNS) to distribute incoming traffic across multiple servers. When a client makes a request to a domain, the DNS server responds with the IP address of one of the available servers, effectively balancing the load among them.
DNS Query: When a user attempts to access a website, their browser sends a DNS query to resolve the domain name into an IP address.
DNS Response: The DNS server responds with one of the IP addresses associated with the domain. This selection can be based on various algorithms, such as round-robin, least connections, or geographic location.
Client Connection: The client connects to the provided IP address, and the request is processed by the corresponding server.
Subsequent Requests: For subsequent requests, the DNS server may return a different IP address, ensuring that the load is distributed evenly across all servers.
While DNS-based load balancing has its advantages, it also comes with limitations:
DNS-based load balancing is a fundamental technique in system design that helps distribute traffic efficiently across multiple servers. Understanding its mechanisms, advantages, and limitations is essential for software engineers and data scientists preparing for technical interviews. By mastering this concept, candidates can demonstrate their knowledge of scalable and resilient system architectures.