Web servers and Load balancers
To understand what a web server and a load balancer are, it's essential to grasp the fundamentals of server infrastructure in modern web applications.
Web Server:
At its core, a server is where we store and host the application data for clients to access. Servers can exist as physical machines or virtual instances in data centers or the cloud. They play a pivotal role in delivering web services.
Servers can scale both horizontally and vertically. Horizontal scaling involves adding more servers to distribute the load efficiently, while vertical scaling enhances a single server's hardware capacity to meet resource demands.
While a server can handle data requests, a web server specializes in managing HTTP requests and responses. It understands how to process these requests and deliver the correct responses. Importantly, web servers can serve static content like HTML and images and route requests to application servers or APIs for dynamic content.
Examples of web servers include Nginx, Apache, Ruby on Rails' Puma, Thin, Laravel's Artisan, and others. The choice depends on the technology stack and specific use case.
Load Balancer:
Load balancers are vital components in modern web architecture. They excel at distributing incoming network traffic, typically HTTP requests, across multiple web servers. This distribution ensures that no single server becomes overwhelmed.
Load balancing isn't just about sharing loads; it also enhances availability, reliability, and performance. It facilitates horizontal scaling, allowing applications to handle increased traffic seamlessly.
Load balancers continuously monitor server health. If a server fails, the load balancer redirects traffic to healthy servers, ensuring uninterrupted service even in the event of a server failure. Various load balancing algorithms exist, including round-robin, least connections, and more advanced methods like weighted load balancing, tailored to specific requirements.
These devices can also offer features such as SSL termination, session persistence, and content-based routing, enhancing security and user experience.
Load balancers can be hardware-based, software-based, or provided as cloud services by hosting providers.
In summary, web servers handle HTTP requests and responses, while load balancers distribute traffic among multiple servers, improving efficiency, availability, and fault tolerance in modern web applications.