Puma Config

puma.rb

#!/usr/bin/env puma

require 'puma_worker_killer'
require 'concurrent'

# Change to match your CPU core count
workers Concurrent.processor_count || 1

# Min and Max threads per worker
min_thread = ENV['RAILS_MIN_THREADS'] || 0
max_thread = ENV['RAILS_MAX_THREADS'] || 16
threads min_thread, max_thread

app_dir = File.expand_path('../../', __FILE__)

shared_dir = "#{app_dir}/shared"

tag 'Puma HTTP Server'

# Default to production
rails_env = ENV['RAILS_ENV'] || "production"
environment rails_env

# Set up socket location
bind "unix://#{shared_dir}/tmp/sockets/puma.sock"

# Logging
stdout_redirect "#{shared_dir}/log/puma.stdout.log", "#{shared_dir}/log/puma.stderr.log", true

# Set master PID and state locations
pidfile "#{shared_dir}/pids/puma.pid"

activate_control_app "unix://#{shared_dir}/tmp/sockets/puma_control.sock"

state_path "/#{shared_dir}/tmp/sockets/puma.state"

worker_timeout 30

worker_boot_timeout 30

prune_bundler true

# If you are preloading your application and using Active Record, it's
# recommended that you close any connections to the database before workers
# are forked to prevent connection leakage.
#
before_fork do
  ActiveRecord::Base.connection_pool.disconnect! if defined?(ActiveRecord)
end

# The code in the `on_worker_boot` will be called if you are using
# clustered mode by specifying a number of `workers`. After each worker
# process is booted, this block will be run. If you are using the `preload_app!`
# option, you will want to use this block to reconnect to any threads
# or connections that may have been created at application boot, as Ruby
# cannot share connections between processes.
#
on_worker_boot do
  ActiveRecord::Base.establish_connection if defined?(ActiveRecord)
end

on_worker_boot do |server, worker|
  PumaWorkerKiller.config do |config|
    config.ram           = 4096  # mb
    config.frequency     = 20    # seconds
    config.percent_usage = 0.95
    config.reaper_status_logs = true
    config.pre_term = -> (worker) { puts "Worker #{worker.inspect} being killed at #{Time.now}" }
  end

  PumaWorkerKiller.start
end