polling with delayed_job

Question

I have a process which takes generally a few seconds to complete so I\'m trying to use delayed_job to handle it asynchronously. The job itself works fine, my question is ho

Answer 1

I ended up using a combination of Delayed_Job with an after(job) callback which populates a memcached object with the same ID as the job created. This way I minimize the number of times I hit the database asking for the status of the job, instead polling the memcached object. And it contains the entire object I need from the completed job, so I don't even have a roundtrip request. I got the idea from an article by the github guys who did pretty much the same thing.

https://github.com/blog/467-smart-js-polling

and used a jquery plugin for the polling, which polls less frequently, and gives up after a certain number of retries

https://github.com/jeremyw/jquery-smart-poll

Seems to work great.

 def after(job)
    prices = Room.prices.where("space_id = ? AND bookdate BETWEEN ? AND ?", space_id.to_i, date_from, date_to).to_a
    Rails.cache.fetch(job.id) do
      bed = Bed.new(:space_id => space_id, :date_from => date_from, :date_to => date_to, :prices => prices)
    end
  end