HAProxy vs Nginx

Nginx is not just a web server; it can do many other tasks equally well including some of the tasks that can be performed by HAProxy. The main advantage of Nginx over HAProxy is the integration that it offers, which also means that you will have to learn just one piece of software to do your job. On the other hand, this is also a disadvantage because everything you do depends on a single piece of software. Additionally, most of the time specialised software tends to perform better than relatively generic tools, has less bugs because it has a smaller implementation and performs faster because it has a simpler design.

Of course, the integration Nginx offers allows you to perform routing based on information found in the HTTP layer, which includes both URL paths and cookies – this also means that Nginx might be able to perform complex tasks more easily. Lastly, Nginx has native support for SSL and is also a caching server. Nevertheless, HAProxy is simpler to install, configure and use and works transparently, which means that after a proper setup, you forget that HAProxy is there. On top of these advantages, HAProxy works with TCP services in general whereas Nginx only works with HTTP. Another point where HAProxy is better is that it revisits a dead server almost as soon as it restarts whereas Nginx waits a while to do so.

The general advice here is to use Nginix when you need a web server; otherwise, using HAProxy is a wiser choice.