Puma Sidekiq Configuration

Errors Recieved

With  the size: attribute in your configure_* blocks removed = 
 ERROR: heartbeat: ERR max number of clients reached
 app[worker.1]: 3 TID-ormcs1tts ERROR: ERR max number of clients reached
 
 
 with the size attribute = " Sidekiq seems to run normally but mailers not moving from in enqueued.
 

Procfile

web: bundle exec puma -e production -C config/puma.rb  
worker: bundle exec sidekiq -e production -C config/sidekiq.yml  

production & Application RB

  Production - Envirorment
  
 
        config.action_mailer.default_url_options = { :host => 'domain.herokuapp.com'}
        Rails.application.routes.default_url_options[:host] = 'domain.herokuapp.com'
        
        
          ActionMailer::Base.delivery_method = :smtp
          config.action_mailer.perform_deliveries = true
          config.action_mailer.raise_delivery_errors = false
          config.action_mailer.default :charset => "utf-8"
          config.action_mailer.smtp_settings = {
              :port => '587',
              :address => 'smtp.mandrillapp.com',
    ....
            }
        config.action_controller.include_all_helpers = true
        ActionMailer::Base.default :from => "App<no-reply@exapp.com>"
        
        config.active_job.queue_name_prefix = "app"
        config.active_job.queue_name_delimiter = "_"
        
        
        
        
        
        
  Application. RB 
  
    config.active_job.queue_adapter = :sidekiq
  
  
  
  
  

Puma.rb

workers Integer(ENV['WEB_CONCURRENCY'] || 2)  
threads_count = Integer(ENV['MAX_THREADS'] || 1)  
threads threads_count, threads_count

preload_app!

rackup      DefaultRackup  
port        ENV['PORT']     || 3000  
environment ENV['RACK_ENV'] || 'development'

# Because we are using preload_app, an instance of our app is created by master process (calling our initializers) and then memory space
# is forked. So we should close DB connection in the master process to avoid connection leaks.
# https://github.com/puma/puma/issues/303
# http://stackoverflow.com/questions/17903689/puma-cluster-configuration-on-heroku
# http://www.rubydoc.info/gems/puma/2.14.0/Puma%2FDSL%3Abefore_fork
# Dont have to worry about Sidekiq's connection to Redis because connections are only created when needed. As long as we are not
# queuing workers when rails is booting, there will be no redis connections to disconnect, so it should be fine.
before_fork do  
  puts "Puma master process about to fork. Closing existing Active record connections."
  ActiveRecord::Base.connection.disconnect!
end

on_worker_boot do  
  # Worker specific setup for Rails 4.1+
  # See: https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server#on-worker-boot
  ActiveRecord::Base.establish_connection
end  

Sidekiq Initializer

if Rails.env.production?

Sidekiq.configure_client do |config|
    config.redis = { url: ENV['REDIS_URL'], size: 2 }
  end

  Sidekiq.configure_server do |config|
    config.redis = { url: ENV['REDIS_URL'], size: 20 }


    Rails.application.config.after_initialize do
      Rails.logger.info("DB Connection Pool size for Sidekiq Server before disconnect is: #{ActiveRecord::Base.connection.pool.instance_variable_get('@size')}")
      ActiveRecord::Base.connection_pool.disconnect!

      ActiveSupport.on_load(:active_record) do
        config = Rails.application.config.database_configuration[Rails.env]
        config['reaping_frequency'] = ENV['DATABASE_REAP_FREQ'] || 10 # seconds
        # config['pool'] = ENV['WORKER_DB_POOL_SIZE'] || Sidekiq.options[:concurrency]
        config['pool'] = 16
        ActiveRecord::Base.establish_connection(config)

        Rails.logger.info("DB Connection Pool size for Sidekiq Server is now: #{ActiveRecord::Base.connection.pool.instance_variable_get('@size')}")
      end
    end
  end


end

sidekiq.yml

:verbose: true

development:  
  :concurrency: 5
production:  
  :concurrency: 20
  
:queues:
  - default