create recurring activejob fails

问题

I'm trying to create an ActiveJob in rails 4.2 that runs at a regular rate. The job is being called the first time, but it does not start again. My code is throwing the exception below after trying to call perform_later.

log output

[ActiveJob] Enqueued ProcessInboxJob (Job ID: 76a63689-e330-47a1-af92-8e4838b508ae) to Inline(default)
[ActiveJob] [ProcessInboxJob] [76a63689-e330-47a1-af92-8e4838b508ae] Performing ProcessInboxJob from Inline(default)
ProcessInboxJob running...
[ActiveJob] [ProcessInboxJob] [76a63689-e330-47a1-af92-8e4838b508ae] [AWS S3 200 0.358441 0 retries] list_objects(:bucket_name=>"...",:max_keys=>1000)  

[ActiveJob] [ProcessInboxJob] [76a63689-e330-47a1-af92-8e4838b508ae] Enqueued ProcessInboxJob (Job ID: dfd3dd7a-06ab-4dba-9bbf-ce1ad606f7e5) to Inline(default) with arguments: {:wait=>30 seconds}
[ActiveJob] [ProcessInboxJob] [76a63689-e330-47a1-af92-8e4838b508ae] Performed ProcessInboxJob from Inline(default) in 599.72ms
Exiting
/Users/antarrbyrd/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/activejob-4.2.0/lib/active_job/arguments.rb:60:in `serialize_argument': Unsupported argument type: ActiveSupport::Duration (ActiveJob::SerializationError)

process_inbox_job.rb

class ProcessInboxJob < ActiveJob::Base
  queue_as :default
  #FREQUENCY = 3.minutes
  def perform()
    # do some work
  end
  # reschedule job
  after_perform do |job|
    self.class.perform_later(wait: 30.seconds)
  end
end

回答1:

The syntax is self.class.set(wait: 30.seconds).perform_later. But that's not a reliable way of doing it as if an exception occurs the chain breaks. Also you must have the initial job scheduled. If you use resque you can use https://rubygems.org/gems/activejob-scheduler

回答2:

As @bcd said, you have to use self.class.set(wait: 30.seconds).perform_later with a queue adapter that support queuing, i.e. not the default (inline) adapter.

I post to give a different point of view on the question of rescheduling, which may help future readers.

after_perform will not be called if an exception is raised but that does not make it a bad place to reschedule a job. If you have an exception in a job, better rescue it (with the class method rescue_from) and send yourself a notification if your backend doesn't do it already.

You can then try to fix the problem (either in the data or in your code) and retry (if you can) or enqueue a similar job again.

For the scheduling part, activejob-scheduler is great and does not work only for resque, but has some down sides.

It uses rufus-scheduler, which performs in-memory delay, so whenever your server restarts you'll lose all scheduling information, which may really be a problem for some tasks (I schedule tasks 1 month in the future and update my app every week, which mean a restart each time).

You also lose all advantages of using an actual queuing backend, such as beanstalk with backburner.

ActiveJob-scheduler also claims to perform job at the exact right time, which is false. The ActiveJob adapter runs at the specified time, but depending on your setup it may take a few time before the job is actually performed, e.g. when you run your jobs on another server.

Lastly, for the initial scheduling you can include a code that checks if the job exists at the worker start, and schedule it if needed.

To sum up,

Yeah ActiveJob-Scheduler is great, but you'll lose some of ActiveJob features and it does not do everything.

回答3:

depending on which queuing system you are using you can try https://github.com/codez/delayed_cron_job or https://github.com/ondrejbartas/sidekiq-cron. With DJ cron you can use UI like rails_admin to actually edit the cron regex. Sidekiq-cron gives you Sinatra web UI where you can manually kick off a job or pause it.

来源：https://stackoverflow.com/questions/27926863/create-recurring-activejob-fails

标签

ruby-on-rails

ruby

rails-activejob