class BackRun::Pubsub

Public Class Methods

new() click to toggle source
# File lib/back_run/pubsub.rb, line 6
def initialize
  @pubsub = Google::Cloud::Pubsub.new(
    project_id: Rails.application.config.back_run[:project_id],
    credentials: Rails.application.config.back_run[:credentials_path]
  )
end

Public Instance Methods

kill_job(job) click to toggle source
# File lib/back_run/pubsub.rb, line 36
def kill_job(job)
  BackRun.logger.info("Moving to morgue queue #{job.klass}")
  publish(job, 'morgue')
end
publish(job, topic = nil) click to toggle source
# File lib/back_run/pubsub.rb, line 13
def publish(job, topic = nil)
  topic_name = topic || job.queue_name
  topic = fetch_topic(topic_name)
  topic.publish(job.to_json)
end
subscribe(worker) click to toggle source

The gem is using Concurrent::CachedThreadPool which overrides the max_threads, so it's ignoring the stream configuration used in the listen method. It may cause that lot's of threads are created when the traffic increases. This PR github.com/googleapis/google-cloud-ruby/pull/3682 fixes that but it's not released yet.

# File lib/back_run/pubsub.rb, line 24
def subscribe(worker)
  worker.queues.each do |queue|
    subscription = subscription_for(queue)
    subscriber = subscription.listen do |message|
      job = Job.from_json(message.data)
      worker.message_received(job, ack_callback(job, message), modify_ack_callback(message))
    end
    subscriber.on_error { |error| BackRun.logger.error(error) }
    subscriber.start
  end
end

Private Instance Methods

ack_callback(job, message) click to toggle source
# File lib/back_run/pubsub.rb, line 48
def ack_callback(job, message)
  proc do
    BackRun.logger.info("Message received from queue: #{job.queue_name}")
    message.ack!
  end
end
fetch_topic(topic_name) click to toggle source
# File lib/back_run/pubsub.rb, line 62
def fetch_topic(topic_name)
  @pubsub.topic(topic_name) || @pubsub.create_topic(topic_name)
end
modify_ack_callback(message) click to toggle source
# File lib/back_run/pubsub.rb, line 55
def modify_ack_callback(message)
  proc do |seconds|
    BackRun.logger.info("Running job in #{seconds} seconds")
    message.modify_ack_deadline!(seconds)
  end
end
subscription_for(queue) click to toggle source
# File lib/back_run/pubsub.rb, line 43
def subscription_for(queue)
  topic = fetch_topic(queue)
  topic.subscription("worker_#{queue}") || topic.subscribe("worker_#{queue}")
end