Class: Resque::Worker

Inherits:
Object
  • Object
show all
Extended by:
Helpers
Includes:
Helpers, Logging
Defined in:
lib/resque/worker.rb

Overview

A Resque Worker processes jobs. On platforms that support fork(2), the worker will fork off a child to process each job. This ensures a clean slate when beginning the next job and cuts down on gradual memory growth as well as low level failures.

It also ensures workers are always listening to signals from you, their master, and can react accordingly.

Constant Summary collapse

@@all_heartbeat_threads = 
[]

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Helpers

classify, constantize

Methods included from Logging

debug, error, fatal, info, log, warn

Constructor Details

#initialize(*queues) ⇒ Worker

Workers should be initialized with an array of string queue names. The order is important: a Worker will check the first queue given for a job. If none is found, it will check the second queue name given. If a job is found, it will be processed. Upon completion, the Worker will again check the first queue given, and so forth. In this way the queue list passed to a Worker on startup defines the priorities of queues.

If passed a single “*”, this Worker will operate on all queues in alphabetical order. Queues can be dynamically added or removed without needing to restart workers using this method.

Workers should have ‘#prepare` called after they are initialized if you are running work on the worker.



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# File 'lib/resque/worker.rb', line 139

def initialize(*queues)
  @shutdown = nil
  @paused = nil
  @before_first_fork_hook_ran = false

  verbose_value = ENV['LOGGING'] || ENV['VERBOSE']
  self.verbose = verbose_value if verbose_value
  self.very_verbose = ENV['VVERBOSE'] if ENV['VVERBOSE']
  self.term_timeout = ENV['RESQUE_TERM_TIMEOUT'] || 4.0
  self.term_child = ENV['TERM_CHILD']
  self.graceful_term = ENV['GRACEFUL_TERM']
  self.run_at_exit_hooks = ENV['RUN_AT_EXIT_HOOKS']

  self.queues = queues
end

Instance Attribute Details

#fork_per_job=(value) ⇒ Object (writeonly)

Sets the attribute fork_per_job

Parameters:

  • value —

    the value to set the attribute fork_per_job to.



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# File 'lib/resque/worker.rb', line 61

def fork_per_job=(value)
  @fork_per_job = value
end

#graceful_term ⇒ Object

should term kill workers gracefully (vs. immediately) Makes SIGTERM work like SIGQUIT



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# File 'lib/resque/worker.rb', line 55

def graceful_term
  @graceful_term
end

#hostname ⇒ Object

chomp’d hostname of this worker’s machine



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# File 'lib/resque/worker.rb', line 759

def hostname
  @hostname ||= Socket.gethostname
end

#job(reload = true) ⇒ Object Also known as: processing

Returns a hash explaining the Job we’re currently processing, if any.



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# File 'lib/resque/worker.rb', line 714

def job(reload = true)
  @job = nil if reload
  @job ||= decode(data_store.get_worker_payload(self)) || {}
end

#pid ⇒ Object

Returns Integer PID of running worker



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# File 'lib/resque/worker.rb', line 764

def pid
  @pid ||= Process.pid
end

#run_at_exit_hooks ⇒ Object

When set to true, forked workers will exit with ‘exit`, calling any `at_exit` code handlers that have been registered in the application. Otherwise, forked workers exit with `exit!`



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# File 'lib/resque/worker.rb', line 59

def run_at_exit_hooks
  @run_at_exit_hooks
end

#term_child ⇒ Object

decide whether to use new_kill_child logic



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# File 'lib/resque/worker.rb', line 51

def term_child
  @term_child
end

#term_timeout ⇒ Object

Returns the value of attribute term_timeout.



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# File 'lib/resque/worker.rb', line 48

def term_timeout
  @term_timeout
end

#to_s ⇒ Object Also known as: id

The string representation is the same as the id for this worker instance. Can be used with ‘Worker.find`.



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# File 'lib/resque/worker.rb', line 753

def to_s
  @to_s ||= "#{hostname}:#{pid}:#{@queues.join(',')}"
end

Class Method Details

.all ⇒ Object

Returns an array of all worker objects.



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# File 'lib/resque/worker.rb', line 67

def self.all
  data_store.worker_ids.map { |id| find(id, :skip_exists => true) }.compact
end

.all_heartbeats ⇒ Object 



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# File 'lib/resque/worker.rb', line 471

def self.all_heartbeats
  data_store.all_heartbeats
end

.all_workers_with_expired_heartbeats ⇒ Object

Returns a list of workers that have sent a heartbeat in the past, but which already expired (does NOT include workers that have never sent a heartbeat at all).



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# File 'lib/resque/worker.rb', line 477

def self.all_workers_with_expired_heartbeats
  workers = Worker.all
  heartbeats = Worker.all_heartbeats
  now = data_store.server_time

  workers.select do |worker|
    id = worker.to_s
    heartbeat = heartbeats[id]

    if heartbeat
      seconds_since_heartbeat = (now - Time.parse(heartbeat)).to_i
      seconds_since_heartbeat > Resque.prune_interval
    else
      false
    end
  end
end

.attach(worker_id) ⇒ Object

Alias of ‘find`



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# File 'lib/resque/worker.rb', line 115

def self.attach(worker_id)
  find(worker_id)
end

.data_store ⇒ Object 



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

def self.data_store
  self.redis
end

.exists?(worker_id) ⇒ Boolean

Given a string worker id, return a boolean indicating whether the worker exists

Returns:

  • (Boolean) 


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# File 'lib/resque/worker.rb', line 121

def self.exists?(worker_id)
  data_store.worker_exists?(worker_id)
end

.find(worker_id, options = {}) ⇒ Object

Returns a single worker object. Accepts a string id.



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

def self.find(worker_id, options = {})
  skip_exists = options[:skip_exists]

  if skip_exists || exists?(worker_id)
    host, pid, queues_raw = worker_id.split(':')
    queues = queues_raw.split(',')
    worker = new(*queues)
    worker.hostname = host
    worker.to_s = worker_id
    worker.pid = pid.to_i
    worker
  else
    nil
  end
end

.kill_all_heartbeat_threads ⇒ Object 



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# File 'lib/resque/worker.rb', line 19

def self.kill_all_heartbeat_threads
  @@all_heartbeat_threads.each(&:kill).each(&:join)
  @@all_heartbeat_threads = []
end

.redis ⇒ Object 



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

def self.redis
  Resque.redis
end

.working ⇒ Object

Returns an array of all worker objects currently processing jobs.



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# File 'lib/resque/worker.rb', line 73

def self.working
  names = all
  return [] unless names.any?

  reportedly_working = {}

  begin
    reportedly_working = data_store.workers_map(names).reject do |key, value|
      value.nil? || value.empty?
    end
  rescue Redis::Distributed::CannotDistribute
    names.each do |name|
      value = data_store.get_worker_payload(name)
      reportedly_working[name] = value unless value.nil? || value.empty?
    end
  end

  reportedly_working.keys.map do |key|
    worker = find(key.sub("worker:", ''), :skip_exists => true)
    worker.job = worker.decode(reportedly_working[key])
    worker
  end.compact
end

Instance Method Details

#==(other) ⇒ Object

Is this worker the same as another worker?



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# File 'lib/resque/worker.rb', line 743

def ==(other)
  to_s == other.to_s
end

#data_store ⇒ Object 



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# File 'lib/resque/worker.rb', line 27

def redis
  Resque.redis
end

#decode(object) ⇒ Object

Given a string, returns a Ruby object.



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# File 'lib/resque/worker.rb', line 44

def decode(object)
  Resque.decode(object)
end

#done_working ⇒ Object

Called when we are done working - clears our ‘working_on` state and tells Redis we processed a job.



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# File 'lib/resque/worker.rb', line 675

def done_working
  data_store.worker_done_working(self) do
    processed!
  end
end

#enable_gc_optimizations ⇒ Object

Enables GC Optimizations if you’re running REE. www.rubyenterpriseedition.com/faq.html#adapt_apps_for_cow



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# File 'lib/resque/worker.rb', line 363

def enable_gc_optimizations
  if GC.respond_to?(:copy_on_write_friendly=)
    GC.copy_on_write_friendly = true
  end
end

#encode(object) ⇒ Object

Given a Ruby object, returns a string suitable for storage in a queue.



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# File 'lib/resque/worker.rb', line 39

def encode(object)
  Resque.encode(object)
end

#failed ⇒ Object

How many failed jobs has this worker seen? Returns an int.



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# File 'lib/resque/worker.rb', line 693

def failed
  Stat["failed:#{self}"]
end

#failed! ⇒ Object

Tells Redis we’ve failed a job.



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# File 'lib/resque/worker.rb', line 698

def failed!
  Stat << "failed"
  Stat << "failed:#{self}"
end

#fork_per_job? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/resque/worker.rb', line 731

def fork_per_job?
  return @fork_per_job if defined?(@fork_per_job)
  @fork_per_job = ENV["FORK_PER_JOB"] != 'false' && Kernel.respond_to?(:fork)
end

#glob_match(pattern) ⇒ Object 



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# File 'lib/resque/worker.rb', line 200

def glob_match(pattern)
  Resque.queues.select do |queue|
    File.fnmatch?(pattern, queue)
  end.sort
end

#heartbeat ⇒ Object 



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# File 'lib/resque/worker.rb', line 459

def heartbeat
  data_store.heartbeat(self)
end

#heartbeat!(time = data_store.server_time) ⇒ Object 



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# File 'lib/resque/worker.rb', line 467

def heartbeat!(time = data_store.server_time)
  data_store.heartbeat!(self, time)
end

#idle? ⇒ Boolean

Boolean - true if idle, false if not

Returns:

  • (Boolean) 


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# File 'lib/resque/worker.rb', line 727

def idle?
  state == :idle
end

#inspect ⇒ Object 



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# File 'lib/resque/worker.rb', line 747

def inspect
  "#<Worker #{to_s}>"
end

#kill_background_threads ⇒ Object 



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# File 'lib/resque/worker.rb', line 623

def kill_background_threads
  if @heartbeat_thread
    @heartbeat_thread_signal.signal
    @heartbeat_thread.join
  end
end

#kill_child ⇒ Object

Kills the forked child immediately, without remorse. The job it is processing will not be completed.



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# File 'lib/resque/worker.rb', line 447

def kill_child
  if @child
    log_with_severity :debug, "Killing child at #{@child}"
    if `ps -o pid,state -p #{@child}`
      Process.kill("KILL", @child) rescue nil
    else
      log_with_severity :debug, "Child #{@child} not found, restarting."
      shutdown
    end
  end
end

#linux_worker_pids ⇒ Object

Find Resque worker pids on Linux and OS X.



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# File 'lib/resque/worker.rb', line 789

def linux_worker_pids
  `ps -A -o pid,command | grep -E "[r]esque:work|[r]esque:\sStarting|[r]esque-[0-9]" | grep -v "resque-web"`.split("\n").map do |line|
    line.split(' ')[0]
  end
end

#log(message) ⇒ Object 



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# File 'lib/resque/worker.rb', line 817

def log(message)
  info(message)
end

#log!(message) ⇒ Object 



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# File 'lib/resque/worker.rb', line 821

def log!(message)
  debug(message)
end

#new_kill_child ⇒ Object

Kills the forked child immediately with minimal remorse. The job it is processing will not be completed. Send the child a TERM signal, wait 5 seconds, and then a KILL signal if it has not quit



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# File 'lib/resque/worker.rb', line 514

def new_kill_child
  if @child
    unless Process.waitpid(@child, Process::WNOHANG)
      log_with_severity :debug, "Sending TERM signal to child #{@child}"
      Process.kill("TERM", @child)
      (term_timeout.to_f * 10).round.times do |i|
        sleep(0.1)
        return if Process.waitpid(@child, Process::WNOHANG)
      end
      log_with_severity :debug, "Sending KILL signal to child #{@child}"
      Process.kill("KILL", @child)
    else
      log_with_severity :debug, "Child #{@child} already quit."
    end
  end
rescue SystemCallError
  log_with_severity :error, "Child #{@child} already quit and reaped."
end

#pause_processing ⇒ Object

Stop processing jobs after the current one has completed (if we’re currently running one).



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# File 'lib/resque/worker.rb', line 540

def pause_processing
  log_with_severity :info, "USR2 received; pausing job processing"
  run_hook :before_pause, self
  @paused = true
end

#paused? ⇒ Boolean

are we paused?

Returns:

  • (Boolean) 


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# File 'lib/resque/worker.rb', line 534

def paused?
  @paused
end

#perform(job) ⇒ Object

Processes a given job in the child.



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# File 'lib/resque/worker.rb', line 293

def perform(job)
  begin
    if fork_per_job?
      reconnect
      run_hook :after_fork, job
    end
    job.perform
  rescue Object => e
    report_failed_job(job,e)
  else
    log_with_severity :info, "done: #{job.inspect}"
  ensure
    yield job if block_given?
  end
end

#prepare ⇒ Object

Daemonizes the worker if ENV is set and writes the process id to ENV if set. Should only be called once per worker.



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# File 'lib/resque/worker.rb', line 158

def prepare
  if ENV['BACKGROUND']
    unless Process.respond_to?('daemon')
        abort "env var BACKGROUND is set, which requires ruby >= 1.9"
    end
    Process.daemon(true)
  end

  if ENV['PIDFILE']
    File.open(ENV['PIDFILE'], 'w') { |f| f << pid }
  end

  self.reconnect if ENV['BACKGROUND']
end

#process(job = nil, &block) ⇒ Object

DEPRECATED. Processes a single job. If none is given, it will try to produce one. Usually run in the child.



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# File 'lib/resque/worker.rb', line 266

def process(job = nil, &block)
  return unless job ||= reserve

  job.worker = self
  working_on job
  perform(job, &block)
ensure
  done_working
end

#processed ⇒ Object

How many jobs has this worker processed? Returns an int.



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# File 'lib/resque/worker.rb', line 682

def processed
  Stat["processed:#{self}"]
end

#processed! ⇒ Object

Tell Redis we’ve processed a job.



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# File 'lib/resque/worker.rb', line 687

def processed!
  Stat << "processed"
  Stat << "processed:#{self}"
end

#procline(string) ⇒ Object

Given a string, sets the procline ($0) and logs. Procline is always in the format of:

RESQUE_PROCLINE_PREFIXresque-VERSION: STRING



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# File 'lib/resque/worker.rb', line 812

def procline(string)
  $0 = "#{ENV['RESQUE_PROCLINE_PREFIX']}resque-#{Resque::Version}: #{string}"
  log_with_severity :debug, $0
end

#prune_dead_workers ⇒ Object

Looks for any workers which should be running on this server and, if they’re not, removes them from Redis.

This is a form of garbage collection. If a server is killed by a hard shutdown, power failure, or something else beyond our control, the Resque workers will not die gracefully and therefore will leave stale state information in Redis.

By checking the current Redis state against the actual environment, we can determine if Redis is old and clean it up a bit.



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# File 'lib/resque/worker.rb', line 563

def prune_dead_workers
  all_workers = Worker.all

  unless all_workers.empty?
    known_workers = worker_pids
    all_workers_with_expired_heartbeats = Worker.all_workers_with_expired_heartbeats
  end

  all_workers.each do |worker|
    # If the worker hasn't sent a heartbeat, remove it from the registry.
    #
    # If the worker hasn't ever sent a heartbeat, we won't remove it since
    # the first heartbeat is sent before the worker is registred it means
    # that this is a worker that doesn't support heartbeats, e.g., another
    # client library or an older version of Resque. We won't touch these.
    if all_workers_with_expired_heartbeats.include?(worker)
      log_with_severity :info, "Pruning dead worker: #{worker}"
      worker.unregister_worker(PruneDeadWorkerDirtyExit.new(worker.to_s))
      next
    end

    host, pid, worker_queues_raw = worker.id.split(':')
    worker_queues = worker_queues_raw.split(",")
    unless @queues.include?("*") || (worker_queues.to_set == @queues.to_set)
      # If the worker we are trying to prune does not belong to the queues
      # we are listening to, we should not touch it.
      # Attempt to prune a worker from different queues may easily result in
      # an unknown class exception, since that worker could easily be even
      # written in different language.
      next
    end

    next unless host == hostname
    next if known_workers.include?(pid)

    log_with_severity :debug, "Pruning dead worker: #{worker}"
    worker.unregister_worker
  end
end

#queues ⇒ Object

Returns a list of queues to use when searching for a job. A splat (“*”) means you want every queue (in alpha order) - this can be useful for dynamically adding new queues.



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# File 'lib/resque/worker.rb', line 195

def queues
  return @static_queues if @static_queues
  @queues.map { |queue| glob_match(queue) }.flatten.uniq
end

#queues=(queues) ⇒ Object 



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# File 'lib/resque/worker.rb', line 173

def queues=(queues)
  queues = queues.empty? ? (ENV["QUEUES"] || ENV['QUEUE']).to_s.split(',') : queues
  @queues = queues.map { |queue| queue.to_s.strip }
  unless ['*', '?', '{', '}', '[', ']'].any? {|char| @queues.join.include?(char) }
    @static_queues = @queues.flatten.uniq
  end
  validate_queues
end

#reconnect ⇒ Object

Reconnect to Redis to avoid sharing a connection with the parent, retry up to 3 times with increasing delay before giving up.



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# File 'lib/resque/worker.rb', line 329

def reconnect
  tries = 0
  begin
    data_store.reconnect
  rescue Redis::BaseConnectionError
    if (tries += 1) <= 3
      log_with_severity :error, "Error reconnecting to Redis; retrying"
      sleep(tries)
      retry
    else
      log_with_severity :error, "Error reconnecting to Redis; quitting"
      raise
    end
  end
end

#redis ⇒ Object 



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# File 'lib/resque/worker.rb', line 24

def redis
  Resque.redis
end

#register_signal_handlers ⇒ Object

Registers the various signal handlers a worker responds to.

TERM: Shutdown immediately, stop processing jobs.

INT: Shutdown immediately, stop processing jobs.

QUIT: Shutdown after the current job has finished processing. USR1: Kill the forked child immediately, continue processing jobs. USR2: Don’t process any new jobs CONT: Start processing jobs again after a USR2



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# File 'lib/resque/worker.rb', line 377

def register_signal_handlers
  trap('TERM') { graceful_term ? shutdown : shutdown!  }
  trap('INT')  { shutdown!  }

  begin
    trap('QUIT') { shutdown   }
    if term_child
      trap('USR1') { new_kill_child }
    else
      trap('USR1') { kill_child }
    end
    trap('USR2') { pause_processing }
    trap('CONT') { unpause_processing }
  rescue ArgumentError
    log_with_severity :warn, "Signals QUIT, USR1, USR2, and/or CONT not supported."
  end

  log_with_severity :debug, "Registered signals"
end

#register_worker ⇒ Object

Registers ourself as a worker. Useful when entering the worker lifecycle on startup.



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# File 'lib/resque/worker.rb', line 605

def register_worker
  data_store.register_worker(self)
end

#remove_heartbeat ⇒ Object 



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# File 'lib/resque/worker.rb', line 463

def remove_heartbeat
  data_store.remove_heartbeat(self)
end

#report_failed_job(job, exception) ⇒ Object

Reports the exception and marks the job as failed



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# File 'lib/resque/worker.rb', line 277

def report_failed_job(job,exception)
  log_with_severity :error, "#{job.inspect} failed: #{exception.inspect}"
  begin
    job.fail(exception)
  rescue Object => exception
    log_with_severity :error, "Received exception when reporting failure: #{exception.inspect}"
  end
  begin
    failed!
  rescue Object => exception
    log_with_severity :error, "Received exception when increasing failed jobs counter (redis issue) : #{exception.inspect}"
  end
end

#reserve ⇒ Object

Attempts to grab a job off one of the provided queues. Returns nil if no job can be found.



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# File 'lib/resque/worker.rb', line 311

def reserve
  queues.each do |queue|
    log_with_severity :debug, "Checking #{queue}"
    if job = Resque.reserve(queue)
      log_with_severity :debug, "Found job on #{queue}"
      return job
    end
  end

  nil
rescue Exception => e
  log_with_severity :error, "Error reserving job: #{e.inspect}"
  log_with_severity :error, e.backtrace.join("\n")
  raise e
end

#run_hook(name, *args) ⇒ Object

Runs a named hook, passing along any arguments.



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# File 'lib/resque/worker.rb', line 610

def run_hook(name, *args)
  return unless hooks = Resque.send(name)
  return if name == :before_first_fork && @before_first_fork_hook_ran
  msg = "Running #{name} hooks"
  msg << " with #{args.inspect}" if args.any?
  log_with_severity :info, msg

  hooks.each do |hook|
    args.any? ? hook.call(*args) : hook.call
    @before_first_fork_hook_ran = true if name == :before_first_fork
  end
end

#shutdown ⇒ Object

Schedule this worker for shutdown. Will finish processing the current job.



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# File 'lib/resque/worker.rb', line 416

def shutdown
  log_with_severity :info, 'Exiting...'
  @shutdown = true
end

#shutdown! ⇒ Object

Kill the child and shutdown immediately. If not forking, abort this process.



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# File 'lib/resque/worker.rb', line 423

def shutdown!
  shutdown
  if term_child
    if fork_per_job?
      new_kill_child
    else
      # Raise TermException in the same process
      trap('TERM') do
        # ignore subsequent terms
      end
      raise TermException.new("SIGTERM")
    end
  else
    kill_child
  end
end

#shutdown? ⇒ Boolean

Should this worker shutdown as soon as current job is finished?

Returns:

  • (Boolean) 


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# File 'lib/resque/worker.rb', line 441

def shutdown?
  @shutdown
end

#solaris_worker_pids ⇒ Object

Find Resque worker pids on Solaris.

Returns an Array of string pids of all the other workers on this machine. Useful when pruning dead workers on startup.



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# File 'lib/resque/worker.rb', line 799

def solaris_worker_pids
  `ps -A -o pid,comm | grep "[r]uby" | grep -v "resque-web"`.split("\n").map do |line|
    real_pid = line.split(' ')[0]
    pargs_command = `pargs -a #{real_pid} 2>/dev/null | grep [r]esque | grep -v "resque-web"`
    if pargs_command.split(':')[1] == " resque-#{Resque::Version}"
      real_pid
    end
  end.compact
end

#start_heartbeat ⇒ Object 



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# File 'lib/resque/worker.rb', line 495

def start_heartbeat
  remove_heartbeat

  @heartbeat_thread_signal = Resque::ThreadSignal.new

  @heartbeat_thread = Thread.new do
    loop do
      heartbeat!
      signaled = @heartbeat_thread_signal.wait_for_signal(Resque.heartbeat_interval)
      break if signaled
    end
  end

  @@all_heartbeat_threads << @heartbeat_thread
end

#started ⇒ Object

What time did this worker start? Returns an instance of ‘Time`



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# File 'lib/resque/worker.rb', line 704

def started
  data_store.worker_start_time(self)
end

#started! ⇒ Object

Tell Redis we’ve started



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# File 'lib/resque/worker.rb', line 709

def started!
  data_store.worker_started(self)
end

#startup ⇒ Object

Runs all the methods needed when a worker begins its lifecycle.



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# File 'lib/resque/worker.rb', line 346

def startup
  $0 = "resque: Starting"

  enable_gc_optimizations
  register_signal_handlers
  start_heartbeat
  prune_dead_workers
  run_hook :before_first_fork
  register_worker

  # Fix buffering so we can `rake resque:work > resque.log` and
  # get output from the child in there.
  $stdout.sync = true
end

#state ⇒ Object

Returns a symbol representing the current worker state, which can be either :working or :idle



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# File 'lib/resque/worker.rb', line 738

def state
  data_store.get_worker_payload(self) ? :working : :idle
end

#unpause_processing ⇒ Object

Start processing jobs again after a pause



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# File 'lib/resque/worker.rb', line 547

def unpause_processing
  log_with_severity :info, "CONT received; resuming job processing"
  @paused = false
  run_hook :after_pause, self
end

#unregister_signal_handlers ⇒ Object 



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# File 'lib/resque/worker.rb', line 397

def unregister_signal_handlers
  trap('TERM') do
    trap ('TERM') do
      # ignore subsequent terms
    end
    raise TermException.new("SIGTERM")
  end
  trap('INT', 'DEFAULT')

  begin
    trap('QUIT', 'DEFAULT')
    trap('USR1', 'DEFAULT')
    trap('USR2', 'DEFAULT')
  rescue ArgumentError
  end
end

#unregister_worker(exception = nil) ⇒ Object

Unregisters ourself as a worker. Useful when shutting down.



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# File 'lib/resque/worker.rb', line 631

def unregister_worker(exception = nil)
  # If we're still processing a job, make sure it gets logged as a
  # failure.
  if (hash = processing) && !hash.empty?
    job = Job.new(hash['queue'], hash['payload'])
    # Ensure the proper worker is attached to this job, even if
    # it's not the precise instance that died.
    job.worker = self
    begin
      job.fail(exception || DirtyExit.new("Job still being processed"))
    rescue RuntimeError => e
      log_with_severity :error, e.message
    end
  end

  kill_background_threads

  data_store.unregister_worker(self) do
    Stat.clear("processed:#{self}")
    Stat.clear("failed:#{self}")
  end
rescue Exception => exception_while_unregistering
  message = exception_while_unregistering.message
  if exception
    message += "\nOriginal Exception (#{exception.class}): #{exception.message}"
    message += "\n  #{exception.backtrace.join("  \n")}" if exception.backtrace
  end
  fail(exception_while_unregistering.class,
       message,
       exception_while_unregistering.backtrace)
end

#validate_queues ⇒ Object

A worker must be given a queue, otherwise it won’t know what to do with itself.

You probably never need to call this.



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# File 'lib/resque/worker.rb', line 186

def validate_queues
  if @queues.nil? || @queues.empty?
    raise NoQueueError.new("Please give each worker at least one queue.")
  end
end

#verbose ⇒ Object 



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# File 'lib/resque/worker.rb', line 826

def verbose
  @verbose
end

#verbose=(value) ⇒ Object 



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# File 'lib/resque/worker.rb', line 834

def verbose=(value);
  if value && !very_verbose
    Resque.logger.formatter = VerboseFormatter.new
    Resque.logger.level = Logger::INFO
  elsif !value
    Resque.logger.formatter = QuietFormatter.new
  end

  @verbose = value
end

#very_verbose ⇒ Object 



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# File 'lib/resque/worker.rb', line 830

def very_verbose
  @very_verbose
end

#very_verbose=(value) ⇒ Object 



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# File 'lib/resque/worker.rb', line 845

def very_verbose=(value)
  if value
    Resque.logger.formatter = VeryVerboseFormatter.new
    Resque.logger.level = Logger::DEBUG
  elsif !value && verbose
    Resque.logger.formatter = VerboseFormatter.new
    Resque.logger.level = Logger::INFO
  else
    Resque.logger.formatter = QuietFormatter.new
  end

  @very_verbose = value
end

#windows_worker_pids ⇒ Object

Returns an Array of string pids of all the other workers on this machine. Useful when pruning dead workers on startup.



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# File 'lib/resque/worker.rb', line 782

def windows_worker_pids
  tasklist_output = `tasklist /FI "IMAGENAME eq ruby.exe" /FO list`.encode("UTF-8", Encoding.locale_charmap)
  tasklist_output.split($/).select { |line| line =~ /^PID:/}.collect{ |line| line.gsub /PID:\s+/, '' }
end

#work(interval = 5.0, &block) ⇒ Object

This is the main workhorse method. Called on a Worker instance, it begins the worker life cycle.

The following events occur during a worker’s life cycle:

  1. Startup: Signals are registered, dead workers are pruned,

    and this worker is registered.

  2. Work loop: Jobs are pulled from a queue and processed.

  3. Teardown: This worker is unregistered.

Can be passed a float representing the polling frequency. The default is 5 seconds, but for a semi-active site you may want to use a smaller value.

Also accepts a block which will be passed the job as soon as it has completed processing. Useful for testing.



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# File 'lib/resque/worker.rb', line 222

def work(interval = 5.0, &block)
  interval = Float(interval)
  startup

  loop do
    break if shutdown?

    unless work_one_job(&block)
      break if interval.zero?
      log_with_severity :debug, "Sleeping for #{interval} seconds"
      procline paused? ? "Paused" : "Waiting for #{queues.join(',')}"
      sleep interval
    end
  end

  unregister_worker
rescue Exception => exception
  return if exception.class == SystemExit && !@child && run_at_exit_hooks
  log_with_severity :error, "Failed to start worker : #{exception.inspect}"
  unregister_worker(exception)
end

#work_one_job(job = nil, &block) ⇒ Object 



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# File 'lib/resque/worker.rb', line 244

def work_one_job(job = nil, &block)
  return false if paused?
  return false unless job ||= reserve

  working_on job
  procline "Processing #{job.queue} since #{Time.now.to_i} [#{job.payload_class_name}]"

  log_with_severity :info, "got: #{job.inspect}"
  job.worker = self

  if fork_per_job?
    perform_with_fork(job, &block)
  else
    perform(job, &block)
  end

  done_working
  true
end

#worker_pids ⇒ Object

Returns an Array of string pids of all the other workers on this machine. Useful when pruning dead workers on startup.



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# File 'lib/resque/worker.rb', line 770

def worker_pids
  if RUBY_PLATFORM =~ /solaris/
    solaris_worker_pids
  elsif RUBY_PLATFORM =~ /mingw32/
    windows_worker_pids
  else
    linux_worker_pids
  end
end

#working? ⇒ Boolean

Boolean - true if working, false if not

Returns:

  • (Boolean) 


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# File 'lib/resque/worker.rb', line 722

def working?
  state == :working
end

#working_on(job) ⇒ Object

Given a job, tells Redis we’re working on it. Useful for seeing what workers are doing and when.



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# File 'lib/resque/worker.rb', line 665

def working_on(job)
  data = encode \
    :queue   => job.queue,
    :run_at  => Time.now.utc.iso8601,
    :payload => job.payload
  data_store.set_worker_payload(self,data)
end