mperham--sidekiq/3.0-Upgrade.md

Upgrading to Sidekiq 3.0

Sidekiq 3.0 brings several new features but also removes old APIs and changes a few data elements in Redis. To upgrade cleanly:

• Upgrade to the latest Sidekiq 2.x and run it for a few weeks. gem 'sidekiq', '< 3' This is only needed if you have retries pending.

• 3rd party gems which use client-side middleware will need to update due to an API change. The Redis connection for a particular job is passed thru the middleware to handle sharding where jobs can be pushed to different redis server instances.

  def call(worker_class, msg, queue, redis_pool)

  Client-side middleware should use redis_pool.with { |conn| ... } to perform Redis operations and not Sidekiq.redis.

• If you used the capistrano integration, you'll need to pull in the new capistrano-sidekiq gem and use it in your deploy.rb.

• API changes:

  • Sidekiq::Client.registered_workers replaced by Sidekiq::Workers.new
  • Sidekiq::Client.registered_queues replaced by Sidekiq::Queue.all
  • Sidekiq::Worker#retries_exhausted replaced by Sidekiq::Worker.sidekiq_retries_exhausted
  • Sidekiq::Workers#each has changed significantly with a reworking of Sidekiq's internal process/thread data model.

• sidekiq/api is no longer automatically required. If your code uses the API, you will need to require it.

• Redis-to-Go is no longer transparently activated on Heroku so as to not play favorites with any particular Redis service. You need to set a config option for your app: heroku config:set REDIS_PROVIDER=REDISTOGO_URL. You may also use the generic REDIS_URL. See Advanced Options: Setting the Location of your Redis server for details.

• Anyone using Airbrake, Honeybadger, Exceptional or ExceptionNotifier will need to update their error gem version to the latest to pull in Sidekiq support. Sidekiq will not provide explicit support for these services so as to not play favorites with any particular error service.

• MRI 1.9 is no longer officially supported. Sidekiq's official support policy is to support the current and previous major releases of MRI and Rails. As of February 2014, that's MRI 2.1, MRI 2.0, JRuby 1.7, Rails 4.0 and Rails 3.2. I will consider PRs to fix issues found by users for other platforms/versions.

Error Service Providers

If you previously provided a middleware to capture job errors, you should instead provide a global error handler with Sidekiq 3.0. This ensures any error within Sidekiq will be logged appropriately, not just during job execution.

if Sidekiq::VERSION < '3'
  # old behavior
  Sidekiq.configure_server do |config|
    config.server_middleware do |chain|
      chain.add MyErrorService::Middleware
    end
  end
else
  Sidekiq.configure_server do |config|
    config.error_handlers << proc {|ex,context| MyErrorService.notify(ex, context) }
  end
end

Your error handler must respond to call(exception, context_hash).