./config/puma.rb

puma.rb

# Puma can serve each request in a thread from an internal thread pool.
# The `threads` method setting takes two numbers: a minimum and maximum.
# Any libraries that use thread pools should be configured to match
# the maximum value specified for Puma. Default is set to 5 threads for minimum
# and maximum; this matches the default thread size of Active Record.
#

# Specifies the `environment` that Puma will run in.
rails_env = ENV['RACK_ENV'] || "development"

if ["production","staging"].include? rails_env
  
  # original
  # /opt/elasticbeanstalk/config/private/pumaconf.rb
  
  directory '/var/app/current'
  threads 8, 32
  workers %x(grep -c processor /proc/cpuinfo)
  bind 'unix:///var/run/puma/my_app.sock'
  stdout_redirect '/var/log/puma/puma.log', '/var/log/puma/puma.log', true
  
  # Specifies the `pidfile` that Puma will use.
  pidfile ENV.fetch("PIDFILE") { "server.pid" }

else

  max_threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }
  min_threads_count = ENV.fetch("RAILS_MIN_THREADS") { max_threads_count }
  threads min_threads_count, max_threads_count
  
  # Specifies the number of `workers` to boot in clustered mode.
  # Workers are forked web server processes. If using threads and workers together
  # the concurrency of the application would be max `threads` * `workers`.
  # Workers do not work on JRuby or Windows (both of which do not support
  # processes).
  #
  # workers ENV.fetch("WEB_CONCURRENCY") { 2 }
  
  # 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!
  
  # Specifies the `pidfile` that Puma will use.
  pidfile ENV.fetch("PIDFILE") { "tmp/server.pid" }
  
end

# Specifies the `environment` that Puma will run in.

environment ENV.fetch("RACK_ENV") { "development" }

# Specifies the `port` that Puma will listen on to receive requests; default is 3000.
#
port  ENV.fetch("PORT") { 3000 }
  
# Allow puma to be restarted by `rails restart` command.
plugin :tmp_restart