Class: Delayed::Worker

Inherits:
Object
  • Object
show all
Includes:
Runnable
Defined in:
lib/delayed/worker.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Runnable

#start

Constructor Details

#initialize ⇒ Worker

Returns a new instance of Worker.



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# File 'lib/delayed/worker.rb', line 40

def initialize
  @failed_reserve_count = 0

  # Reset lifecycle on the offhand chance that something lazily
  # triggered its creation before all plugins had been registered.
  Delayed.setup_lifecycle
end

Instance Attribute Details

#name ⇒ Object

Every worker has a unique name which by default is the pid of the process. There are some advantages to overriding this with something which survives worker restarts: Workers can safely resume working on tasks which are locked by themselves. The worker will assume that it crashed before.



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# File 'lib/delayed/worker.rb', line 52

def name
  return @name unless @name.nil?

  begin
    "#{@name_prefix}host:#{Socket.gethostname} pid:#{Process.pid}"
  rescue StandardError
    "#{@name_prefix}pid:#{Process.pid}"
  end
end

#name_prefix ⇒ Object

name_prefix is ignored if name is set directly



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# File 'lib/delayed/worker.rb', line 33

def name_prefix
  @name_prefix
end

Instance Method Details

#failed(job) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 166

def failed(job)
  self.class.lifecycle.run_callbacks(:failure, self, job) do
    job.hook(:failure)
  end
rescue StandardError => e
  say "Error when running failure callback: #{e}", 'error'
  say e.backtrace.join("\n"), 'error'
ensure
  job.destroy_failed_jobs? ? job.destroy : job.fail!
end

#job_say(job, text, level = Delayed.default_log_level) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 177

def job_say(job, text, level = Delayed.default_log_level)
  text = "Job #{job.name} (id=#{job.id})#{say_queue(job.queue)} #{text}"
  say text, level
end

#max_attempts(job) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 187

def max_attempts(job)
  job.max_attempts || self.class.max_attempts
end

#max_run_time(job) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 191

def max_run_time(job)
  job.max_run_time || self.class.max_run_time
end

#on_exit! ⇒ Object 



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# File 'lib/delayed/worker.rb', line 79

def on_exit!
  Delayed::Job.clear_locks!(self)
end

#perform(job) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 122

def perform(job)
  self.class.lifecycle.run_callbacks(:perform, self, job) do
    metadata = {
      status: 'RUNNING',
      name: job.name,
      run_at: job.run_at,
      created_at: job.created_at,
      priority: job.priority,
      queue: job.queue,
      attempts: job.attempts,
      enqueued_for: (Time.current - job.created_at).round,
    }
    job_say job, metadata.to_json
    run_time = Benchmark.realtime do
      Timeout.timeout(max_run_time(job).to_i, WorkerTimeout) do
        job.invoke_job
      end
      job.destroy
    end
    job_say job, format('COMPLETED after %.4f seconds', run_time)
  end
  true # did work
rescue DeserializationError => e
  handle_unrecoverable_error(job, e)
  false # work failed
rescue Exception => e # rubocop:disable Lint/RescueException
  handle_erroring_job(job, e)
  false # work failed
end

#reschedule(job, time = nil) ⇒ Object

Reschedule the job in the future (when a job fails). Uses an exponential scale depending on the number of failed attempts.



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# File 'lib/delayed/worker.rb', line 154

def reschedule(job, time = nil)
  if (job.attempts += 1) < max_attempts(job)
    time ||= job.reschedule_at
    job.run_at = time
    job.unlock
    job.save!
  else
    job_say job, "FAILED permanently because of #{job.attempts} consecutive failures", 'error'
    failed(job)
  end
end

#run! ⇒ Object 



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# File 'lib/delayed/worker.rb', line 66

def run!
  @realtime = Benchmark.realtime do
    @result = work_off
  end

  count = @result[0] + @result[1]

  say format("#{count} jobs processed at %.4f j/s, %d failed", count / @realtime, @result.last) if count.positive?
  interruptable_sleep(self.class.sleep_delay) if count < max_claims

  reload! unless stop?
end

#say(text, level = Delayed.default_log_level) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 182

def say(text, level = Delayed.default_log_level)
  text = "[Worker(#{name})] #{text}"
  Delayed.say("#{Time.now.strftime('%FT%T%z')}: #{text}", level)
end

#work_off(num = 100) ⇒ Object

Do num jobs and return stats on success/failure. Exit early if interrupted.



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# File 'lib/delayed/worker.rb', line 85

def work_off(num = 100)
  success = Concurrent::AtomicFixnum.new(0)
  total = 0

  while total < num
    start = clock_time
    jobs = reserve_jobs
    break if jobs.empty?

    total += jobs.length
    pool = Concurrent::FixedThreadPool.new(jobs.length)
    jobs.each do |job|
      pool.post do
        self.class.lifecycle.run_callbacks(:thread, self) do
          success.increment if perform(job)
        rescue DeserializationError => e
          handle_unrecoverable_error(job, e)
        rescue Exception => e # rubocop:disable Lint/RescueException
          handle_erroring_job(job, e)
        end
      rescue Exception => e # rubocop:disable Lint/RescueException
        say "Job thread crashed with #{e.class.name}: #{e.message}", 'error'
      end
    end

    pool.shutdown
    pool.wait_for_termination

    break if stop? # leave if we're exiting

    elapsed = clock_time - start
    interruptable_sleep(self.class.min_reserve_interval - elapsed)
  end

  [success.value, total - success.value]
end