Heroku + Rails + Sidekiq 4.0 Config

Procfile

web: bundle exec puma -C config/puma.rb -p $PORT
worker: bundle exec sidekiq -e $RAILS_ENV -q default -q mailers

# By default, sidekiq only operates on the `default` queue
# So if you do `Mailer.new(...).deliver_later`, those are queued to the `mailers` queue
# Hence you need to explicitly tell Sidekiq to operate on `mailers` queue too
# You can also put this into sidekiq.yml

sidekiq.rb

# config/initializers/sidekiq.rb

require 'sidekiq_calculations'

if defined?(Sidekiq)
  Sidekiq::Worker::ClassMethods.class_eval do
    def perform_async_with_retry(*args)
      perform_async_count = 0
      begin
        perform_async_without_retry(*args)
      rescue Redis::CannotConnectError
        if (perform_async_count+=1) <= 3
          sleep 1
          retry
        else
          raise
        end
      end
    end
    alias_method :perform_async_without_retry, :perform_async
    alias_method :perform_async, :perform_async_with_retry
  end

  # NOTE: The configuration hash must have symbolized keys.
  Sidekiq.configure_client do |config|
    sidekiq_calculations = SidekiqCalculations.new
    sidekiq_calculations.raise_error_for_env!

    config.redis = {
      url: ENV['REDISCLOUD_URL'],
      size: sidekiq_calculations.client_redis_size
    }
  end

  # NOTE: The configuration hash must have symbolized keys.
  Sidekiq.configure_server do |config|
    sidekiq_calculations = SidekiqCalculations.new
    sidekiq_calculations.raise_error_for_env!

    config.options[:concurrency] = sidekiq_calculations.server_concurrency_size
    config.redis = {
      url: ENV['REDISCLOUD_URL']
    }
  end
end

sidekiq_calculations.rb

# lib/sidekiq_calculations

class SidekiqCalculations
  DEFAULT_CLIENT_REDIS_SIZE  = 2
  DEFAULT_SERVER_CONCURRENCY = 25

  def raise_error_for_env!
    return if !Rails.env.production?

    max_redis_connection
    web_dynos
    worker_dynos
  rescue KeyError, TypeError # Integer(nil) raises TypeError
    raise <<-ERROR
Sidekiq Server Configuration failed.
!!!======> Please add ENV:
  - MAX_REDIS_CONNECTION
  - NUMBER_OF_WEB_DYNOS
  - NUMBER_OF_WORKER_DYNOS
    ERROR
  end

  def client_redis_size
    return DEFAULT_CLIENT_REDIS_SIZE if !Rails.env.production?

    puma_workers * (puma_threads/2) * web_dynos
  end

  def server_concurrency_size
    return DEFAULT_SERVER_CONCURRENCY if !Rails.env.production?

    (max_redis_connection - client_redis_size - sidekiq_reserved) / paranoid_divisor
  end

  private
    def web_dynos
      Integer(ENV.fetch('NUMBER_OF_WEB_DYNOS'))
    end

    def worker_dynos
      Integer(ENV.fetch('NUMBER_OF_WORKER_DYNOS'))
    end

    def max_redis_connection
      Integer(ENV.fetch('MAX_REDIS_CONNECTION'))
    end

    # Copied from `config/puma.rb`.
    # If default changes, then this needs to be updated
    def puma_workers
      Integer(ENV.fetch("WEB_CONCURRENCY", 2))
    end

    # Copied from `config/puma.rb`.
    # If default changes, then this needs to be updated
    def puma_threads
      Integer(ENV.fetch("WEB_MAX_THREADS", 5))
    end

    def sidekiq_reserved
      2
    end

    # This is added to bring down the value of Concurrency
    # so that there's leeway to grow
    def paranoid_divisor
      2
    end
end

Do I need to set all of the ENV variables that are defined here?