[adambyrtek]

One of these "other things" is buffering of slow HTTP requests. Application servers are usually not designed to deal with that and are meant to be run behind a proper load balancer/reverse proxy. This is usually very explicitly mentioned in their documentation, for example in https://bogomips.org/unicorn/PHILOSOPHY.html

[jrochkind1]

puma does pretty good at buffering slow HTTP requests though.

I honestly _don't know_ why we usually put apache or nginx in front of our ruby 'web servers'. But I keep doing it anyway, cause 'everyone else' does, and I don't want to take the time to be sure I don't need to, it works.

However, I believe rails deployments to Heroku generally _don't_ put another web server in front. Which, per your point, slow clients is quite exactly why they explained the switch from unicorn to puma as a default web server. https://devcenter.heroku.com/changelog-items/594

It is true that in 2018 web dev has gotten complicated (in a variety of different axes), and if there's a framework/platform that will allow you to not know it is, I don't know what it is! It would probably be one that made a lot more choices for you though (like, say, ruby web server, so you don't need to think about 'oh, unicorn can't handle slow clients but puma can') -- which is the opposite of Sinatra's philosophy -- but then again Rails approach to try to do that has not resulted in something people find easy either. shrug.

[nathan_f77]

I've stopped using Nginx in my Docker containers, and I just run puma directly. It's still behind a load balancer that also handles TLS termination. I also serve all the assets from the Rails server, but they're cached with a CDN, so it only needs to serve each file once.

If you're using Docker with Kubernetes, Convox, Docker Swarm, Rancher, etc., then I don't think you need to run Nginx or Apache. I ran some load tests on my staging environment with and without Nginx, and it didn't make any difference.

This was a really good article that helped me understand request routing a bit better: https://www.speedshop.co/2015/07/29/scaling-ruby-apps-to-100...

[jrochkind1]

If you weren't caching with CDN, would serving those static assets as efficiently as possible be a good reason to keep using (eg) nginx, do you think?

Oh, I guess load balancing (with a multiple-host scale) is another good reason, if you don't have heroku doing it for you, nginx is a convenient way to do it just fine.

[nathan_f77]

I don't know if there's any middle ground where you'd want to use Nginx instead of a CDN. If it's an internal app then it doesn't really matter. But if you have any reason to worry about the performance of serving static assets, then you should always be using a CDN like CloudFront or CloudFlare, etc.

But yeah, Nginx can be a great solution for load balancing and TLS termination.

[regularfry]

I always used to do it for static asset serving, where anything standing between the socket and a sendfile() call is a waste of space. I honestly don't know how good Puma is at sending files, but I wouldn't be shocked to learn it was still worthwhile there.