Puma Worker Configuration (#1701)

We noticed that the current default settings perform very poorly under
load. We managed to literally take down Greenlight during a larger event
when people where accessing the landing page for rooms and when doing
some tests, I was more or less able to DoS Greenlight on my own.

This patch adds a default worker configuration similar to the previous
configuration with one worker, but lets users easily adjust it to more
workers which significantly improves the situation. The small, 4 core
machine I was testing on could handle about thrice the amount of
requests.

Co-authored-by: Ahmad Farhat <ahmad.af.farhat@gmail.com>

config/puma.rb

@@ -23,14 +23,14 @@ environment ENV.fetch("RAILS_ENV") { "development" }
 # Workers do not work on JRuby or Windows (both of which do not support
 # processes).
 #
-# workers ENV.fetch("WEB_CONCURRENCY") { 2 }
+workers ENV.fetch("WEB_CONCURRENCY") { 1 }
 
 # Use the `preload_app!` method when specifying a `workers` number.
 # This directive tells Puma to first boot the application and load code
 # before forking the application. This takes advantage of Copy On Write
 # process behavior so workers use less memory.
 #
-# preload_app!
+preload_app!
 
 # Allow puma to be restarted by `rails restart` command.
 plugin :tmp_restart