Published on 2023-01-29
WebTechLife is complicated. There are so many options to do something and every choice carries pros and cons. So is hosting your website 😬! In this post, we look at different types of web server software available in the market. Reading Time: ~ 5 mins.
Every Website sits on a computer known as a Web server. It stores your website components such as HTML files, images, styling sheet, etc. In addition to storing your website components, Web server also must have a HTTP (Hypertext Transfer Protocol) Server Software that understands URLs (web addresses) and the protocol your browser uses to view the web pages. There are many HTTP/ Web servers, with many configuration possibilities.
Here's non-exhaustive list of HTTP Servers (Web Servers application):
Apache HTTP Server This is the most popular web server software in the world developed by the Apache Software Foundation. Apache web server is an open source software and can be installed on almost all operating systems including Linux, Unix, Windows, Mac OS X and more. About 60% of the web server machines run the Apache Web Server. For web application written in Java, Apache with tomcat is a go-to.
Nginx Nginx is the second most commonly used server for the top 100,000 websites and often serves as a reverse proxy for Python WSGI servers.
Internet Information Services (IIS) IIS is a web server software provided by Microsoft. No surprise it comes with Windows Operating System, you need to enable it though. It is not auto-installed on your Windows Machine. IIS can be used to host, deploy, and manage web applications using technologies such as ASP.NET and PHP.
Communication between HTTP Web Server Software and Web Application (App Server Software) But how do HTTP Web Server Software like Apache, Nginix, etc. communicated to your web application? This is where FastCGI comes in. Basically, it is a Common Gateway Interface Software which uses a simple packet record format on the connection between the application and the Web server. Most application developers will use the FastCGI application library and won’t have to worry about the protocol. For more details, refer to White Paper.
WSGI Servers vs HTTP Servers Before the boom of Machine Learning, Python is just a scripting language used to automate the manual tasks. The scripting languages are interpreted language converted into bytecode that is then executed by the Python virtual machine whereas a compiled language (Java, C++, etc.) is transformed into machine understandable language 0110..). Other popular scripting languages are Perl, Visual Basic, JavaScript, Unix Shell Scripts, ECMAScript, and Bash etc.
A traditional web server (HTTP Server Software) does not understand or have any ways to run Python applications. Therefore, Python community came up with Web Server Gateway Interface as a standard interface that modules and containers could implement. WSGI is now the accepted approach for running Python web applications.
WSGI servers have HTTP servers built-in, converting incoming HTTP requests to the standard WSGI environ, and converting outgoing WSGI responses to HTTP responses. However, a dedicated HTTP server may be safer, more efficient, or more capable. Putting an HTTP server in front of the WSGI server is called a reverse proxy.
The reasons we need to add a proxy HTTP server (example: Nginx) in front of the WSGI server are - Serve static files - Manage domain name routings - Securing communication with external parties (SSL) - etc.
Development vs Production Almost all the website use a web application framework. Some web application frameworks include simple HTTP servers for development.
For example, the Django framework provides runserver and PHP has a built-in web server php -S localhost:{port} while Flask has a WSGI server flask run --host={localhost} --port={port} which converts incoming HTTP requests to the standard WSGI environ, and then transform outgoing WSGI responses to HTTP responses.
These are generally intended only for use during initial development and not designed to be particularly secure, stable, or efficient. Therefore, instead of using a built-in WSGI server of Flask, we should use Gunicorn 'Green Unicorn', a Python WSGI HTTP Server. Alternative is uWSGI.
Takeaways There are many layers of components to make a website available online. HTTP Web Server Software are sometimes simply refer to as Web Server which can be confusing to non-techies. They are actually software that support HTTP Web Protocol. Front-end components of website are associated with HTTP Web Server Software. All of these software and files sit on the computing device known as Server. Since it is interfacing the public/ client request for HTTP, that computing device/machine is known as Web Server.
These days, there are many web hosting services such as GoDaddy where you can host your website with a single click. I, sometimes, worry if the next generation would ever know the hardships at the beginning of internet, where everything has to be configured and setup by ourselves. What would happen one day when everything went offline and we have to do all the things we take granted for manually?
Further Reading Usage of web servers broken down by ranking