Here are my configs for sidekiq

sidekiq.rb

require 'sidekiq'
require 'autoscaler/sidekiq'
require 'autoscaler/heroku_scaler'

heroku = nil
if ENV['HEROKU_APP']
  heroku = Autoscaler::HerokuScaler.new
end

Sidekiq.configure_server do |config|

  if Rails.env.development?
    config.redis = { :url => 'redis://localhost:6379', :size => 25 }
  else
    config.redis = { :url => ENV["OPENREDIS_URL"], :size => 25 }
    ENV["REDIS_PROVIDER"] = "OPENREDIS_URL"
  end

  config.server_middleware do |chain|
    if heroku
      p "[Sidekiq] Running on Heroku, autoscaler is used"
      chain.add(Autoscaler::Sidekiq::Server, heroku, 60) # 60 seconds timeout
    else
      p "[Sidekiq] Running locally, so autoscaler isn't used"
    end
  end
end

unicorn.rb

require 'sidekiq'
require 'autoscaler/sidekiq'
require 'autoscaler/heroku_scaler'

worker_processes 3
timeout 30
preload_app true

before_fork do |server, worker|
  # Replace with MongoDB or whatever
  if defined?(ActiveRecord::Base)
    ActiveRecord::Base.connection.disconnect!
    Rails.logger.info('Disconnected from ActiveRecord')
  end

  sleep 1
end

after_fork do |server, worker|
  # Replace with MongoDB or whatever
  if defined?(ActiveRecord::Base)
    ActiveRecord::Base.establish_connection
    Rails.logger.info('Connected to ActiveRecord')
  end

  heroku = nil
  if ENV['HEROKU_APP']
    heroku = Autoscaler::HerokuScaler.new
  end

  Sidekiq.configure_client do |config|
    if Rails.env.development?
      config.redis = { :url => 'redis://localhost:6379', :namespace => 'prime', :size => 25 }
    else
      config.redis = { :url => ENV["OPENREDIS_URL"], :namespace => 'prime', :size => 25 }
    end
    if heroku
      config.client_middleware do |chain|
        chain.add Autoscaler::Sidekiq::Client, 'default' => heroku
      end
    end
  end

end