# Welcome to Sidekiq Pro 3.0! Sidekiq Pro 3.0 is designed to work with Sidekiq 4.0. ## What's New * **Redis 2.8.0 or greater is required.** Redis 2.8 was released two years ago and contains **many** useful features which Sidekiq couldn't leverage until now. **Redis 3.0.3 or greater is recommended** for large scale use. * Sidekiq Pro no longer uses Celluloid. If your application code uses Celluloid, you will need to pull it in yourself. * Pausing and unpausing queues is now instantaneous, no more polling! * Reliable fetch has been re-implemented due to the fetch changes in Sidekiq 4.0. * Support for platforms without persistent hostnames. Since reliable fetch normally requires a persistent hostname, you may disable hostname usage on platforms like Heroku and Docker: ```ruby Sidekiq.configure_server do |config| config.options[:ephemeral_hostname] = true config.reliable_fetch! end ``` This option is enabled automatically if Heroku's DYNO environment variable is present. Without a persistent hostname, each Sidekiq process **must** have its own unique index. * The old 'sidekiq/notifications' features have been removed. ## Upgrade First, make sure you are using Redis 2.8 or greater. Next: * Upgrade to the latest Sidekiq Pro 2.x. ```ruby gem 'sidekiq-pro', '< 3' ``` * Fix any deprecation warnings you see. * Upgrade to 3.x. ```ruby gem 'sidekiq-pro', '< 4' ```