Sidekiq - Prevent worker from being executed in specific machine - ruby-on-rails

Question

I'm working on a Rails project that uses Sidekiq. Our Sidekiq implementation has two workers (WorkerA, that reads queue_a, and WorkerB, which reads queue_b). One of them has to be executed in the same server the Rails app is and the other one in a different server(s). How can I prevent WorkerB from being executed in the first server, and vice versa? Can a Sidekiq process be configured to run just specific workers?
EDIT:
The Redis server is in the same machine the Rails app is.

Answer 1

Use a hostname-specific queue. config/sidekiq.yml:
---
:verbose: false
:concurrency: 25
:queues:
- default
- <%= `hostname`.strip %>
In your worker:
class ImageUploadProcessor
include Sidekiq::Worker
sidekiq_options queue: `hostname`.strip
def perform(filename)
# process image
end
end
More detail on my blog:
http://www.mikeperham.com/2013/11/13/advanced-sidekiq-host-specific-queues/

Answer 2

well, here is the way to start sidekiq with options
nohup bundle exec sidekiq -q queue_a queue_b -c 5 -e #{Rails.env} -P #{pidfile} 2>&1 &
you can start sidekiq with specific workers
you can run nohup bundle exec sidekiq -q queue_a -c 5 -e #{Rails.env} -P #{pidfile} 2>&1 & to execute only WorkA
to distinguish different workers on different servers, just do like below:
system "nohup bundle exec sidekiq -q #{workers_string} -c 5 -e #{Rails.env} -P #{pidfile} 2>&1 &"
def workers_string
if <on server A> # using ENV or serverip to distinguish
"queue_a"
elsif <on server B>
"queue_b queue_b ..."
end
end
#or you can set the workers_strings into config file on different servers