Passenger, Unicorn or Puma?

Question

Ruby on Rails

Never put a rails stack on a server before. Server choice.
The frontend will be nginx, the application is not highly loaded.
What do you advise?
What solution is promising and universal?
PS This server also has other sites in other languages.

Answer 1

At first I used unicorn, because most of the tutorials on it were.
Often faced with the fact that the zero-down-time refused to work for me over time for unknown reasons (probably to blame).
Then I saw that Heroku switched to puma + in one of the projects it was necessary to make several flows in development, somehow subjectively it seemed that it was easier with puma. But the passenger somehow didn’t get it right: for some reason it seems like a monstrous thing, and I also came across articles that were not very positive on it.
They say that all the advantages of the cougar in the speed of work with multithreading, especially with JRuby. I also heard a phrase like "If there is a Puma, why do you need something else?"
I don't really think the difference will be noticeable on an average project. Also, none of them interfere with other stacks. And the setup in the basic form is equally simple.

Answer 2

A very subjective analysis, but this is the state of things on my production server.
100% = 512mb RAM;
Blue line = Debian 8 + Stackdriver agent + Puma (Rails 5 {MyApp})
Orange line = Debian 8 + Stackdriver agent + Passenger (Rails 5 {MyApp})
Minimal blue line drops are manual server restarts, memory spikes are batch processing and loading images, but according to my observations, as a rule, Puma eats and eats memory and does not give it away, at all. I don’t know if this is a feature of the cougar or not, but under normal load, (just site traffic), the passenger did not notice a tendency to eat memory.
Ps Passenger Open Source ( Version 5.1.4 Standalone )
Puma (Which comes with 5 rails)

Answer 3

The passenger simply restarts the application on his own
in the fifth version, the performance is not worse than that of the cougar
, in general, it is logical to use what you are familiar with.