Class: Delayed::Worker

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

Constant Summary collapse

DEFAULT_SLEEP_DELAY = 
5
DEFAULT_MAX_ATTEMPTS = 
25
DEFAULT_MAX_RUN_TIME = 
4.hours
DEFAULT_DEFAULT_PRIORITY = 
0
DEFAULT_DELAY_JOBS = 
true
DEFAULT_QUEUES = 
[]
DEFAULT_READ_AHEAD = 
5

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Worker

Returns a new instance of Worker.



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# File 'lib/delayed/worker.rb', line 98

def initialize(options={})
  @quiet = options.has_key?(:quiet) ? options[:quiet] : true
  self.class.min_priority = options[:min_priority] if options.has_key?(:min_priority)
  self.class.max_priority = options[:max_priority] if options.has_key?(:max_priority)
  self.class.sleep_delay  = options[:sleep_delay] if options.has_key?(:sleep_delay)
  self.class.read_ahead   = options[:read_ahead] if options.has_key?(:read_ahead)
  self.class.queues       = options[:queues] if options.has_key?(:queues)

  self.plugins.each { |klass| klass.new }
end

Instance Attribute Details

#name_prefix ⇒ Object

name_prefix is ignored if name is set directly



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# File 'lib/delayed/worker.rb', line 29

def name_prefix
  @name_prefix
end

Class Method Details

.after_fork ⇒ Object 



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# File 'lib/delayed/worker.rb', line 81

def self.after_fork
  # Re-open file handles
  @files_to_reopen.each do |file|
    begin
      file.reopen file.path, "a+"
      file.sync = true
    rescue ::Exception
    end
  end

  backend.after_fork
end

.backend=(backend) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 56

def self.backend=(backend)
  if backend.is_a? Symbol
    require "delayed/serialization/#{backend}"
    require "delayed/backend/#{backend}"
    backend = "Delayed::Backend::#{backend.to_s.classify}::Job".constantize
  end
  @@backend = backend
  silence_warnings { ::Delayed.const_set(:Job, backend) }
end

.before_fork ⇒ Object 



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# File 'lib/delayed/worker.rb', line 70

def self.before_fork
  unless @files_to_reopen
    @files_to_reopen = []
    ObjectSpace.each_object(File) do |file|
      @files_to_reopen << file unless file.closed?
    end
  end

  backend.before_fork
end

.guess_backend ⇒ Object 



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

def self.guess_backend
  warn "[DEPRECATION] guess_backend is deprecated. Please remove it from your code."
end

.lifecycle ⇒ Object 



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# File 'lib/delayed/worker.rb', line 94

def self.lifecycle
  @lifecycle ||= Delayed::Lifecycle.new
end

.reset ⇒ Object 



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# File 'lib/delayed/worker.rb', line 31

def self.reset
  self.sleep_delay      = DEFAULT_SLEEP_DELAY
  self.max_attempts     = DEFAULT_MAX_ATTEMPTS
  self.max_run_time     = DEFAULT_MAX_RUN_TIME
  self.default_priority = DEFAULT_DEFAULT_PRIORITY
  self.delay_jobs       = DEFAULT_DELAY_JOBS
  self.queues           = DEFAULT_QUEUES
  self.read_ahead       = DEFAULT_READ_AHEAD
end

Instance Method Details

#failed(job) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 212

def failed(job)
  self.class.lifecycle.run_callbacks(:failure, self, job) do
    job.hook(:failure)
    self.class.destroy_failed_jobs ? job.destroy : job.fail!
  end
end

#max_attempts(job) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 225

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

#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 retarts: 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 113

def name
  return @name unless @name.nil?
  "#{@name_prefix}host:#{Socket.gethostname} pid:#{Process.pid}" rescue "#{@name_prefix}pid:#{Process.pid}"
end

#name=(val) ⇒ Object

Sets the name of the worker. Setting the name to nil will reset the default worker name



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# File 'lib/delayed/worker.rb', line 120

def name=(val)
  @name = val
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 200

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
    say "PERMANENTLY removing #{job.name} because of #{job.attempts} consecutive failures.", Logger::INFO
    failed(job)
  end
end

#run(job) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 183

def run(job)
  runtime =  Benchmark.realtime do
    Timeout.timeout(self.class.max_run_time.to_i) { job.invoke_job }
    job.destroy
  end
  say "#{job.name} completed after %.4f" % runtime
  return true  # did work
rescue DeserializationError => error
  job.last_error = "#{error.message}\n#{error.backtrace.join("\n")}"
  failed(job)
rescue Exception => error
  self.class.lifecycle.run_callbacks(:error, self, job){ handle_failed_job(job, error) }
  return false  # work failed
end

#say(text, level = Logger::INFO) ⇒ Object 



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# File 'lib/delayed/worker.rb', line 219

def say(text, level = Logger::INFO)
  text = "[Worker(#{name})] #{text}"
  puts text unless @quiet
  logger.add level, "#{Time.now.strftime('%FT%T%z')}: #{text}" if logger
end

#start ⇒ Object 



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# File 'lib/delayed/worker.rb', line 124

def start
  trap('TERM') { say 'Exiting...'; stop }
  trap('INT')  { say 'Exiting...'; stop }

  say "Starting job worker"

  self.class.lifecycle.run_callbacks(:execute, self) do
    loop do
      self.class.lifecycle.run_callbacks(:loop, self) do
        result = nil

        realtime = Benchmark.realtime do
          result = work_off
        end

        count = result.sum

        break if stop?

        if count.zero?
          sleep(self.class.sleep_delay)
        else
          say "#{count} jobs processed at %.4f j/s, %d failed ..." % [count / realtime, result.last]
        end
      end

      break if stop?
    end
  end
end

#stop ⇒ Object 



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# File 'lib/delayed/worker.rb', line 155

def stop
  @exit = true
end

#stop? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/delayed/worker.rb', line 159

def stop?
  !!@exit
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 165

def work_off(num = 100)
  success, failure = 0, 0

  num.times do
    case reserve_and_run_one_job
    when true
        success += 1
    when false
        failure += 1
    else
      break  # leave if no work could be done
    end
    break if stop? # leave if we're exiting
  end

  return [success, failure]
end