Class: Delayed::Worker

Inherits:
Object
  • Object
show all
Includes:
Logging
Defined in:
lib/delayed/worker.rb,
lib/delayed/worker/health_check.rb,
lib/delayed/worker/process_helper.rb,
lib/delayed/worker/null_health_check.rb,
lib/delayed/worker/consul_health_check.rb

Defined Under Namespace

Modules: ProcessHelper Classes: ConsulHealthCheck, HealthCheck, NullHealthCheck

Constant Summary collapse

SIGNALS = 
%i{INT TERM QUIT}
LINUX_PAGE_SIZE =

linux w/ proc fs

(size = `getconf PAGESIZE`.to_i; size > 0 ? size : 4096)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Logging

logger, #logger, #say

Constructor Details

#initialize(options = {}) ⇒ Worker

Returns a new instance of Worker.



47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
 
# File 'lib/delayed/worker.rb', line 47

def initialize(options = {})
  @exit = false
  @parent_pid = options[:parent_pid]
  @queue_name = options[:queue] ||= Settings.queue
  @min_priority = options[:min_priority]
  @max_priority = options[:max_priority]
  @max_job_count = options[:worker_max_job_count].to_i
  @max_memory_usage = options[:worker_max_memory_usage].to_i
  @work_queue = options.delete(:work_queue) || WorkQueue::InProcess.new
  @health_check_type = Settings.worker_health_check_type
  @health_check_config = Settings.worker_health_check_config
  @config = options
  @job_count = 0

  @self_pipe = IO.pipe
  @signal_queue = []

  app = Rails.application
  if app && !app.config.cache_classes
    Delayed::Worker.lifecycle.around(:perform) do |worker, job, &block|
      reload = app.config.reload_classes_only_on_change != true || app.reloaders.map(&:updated?).any?

      if reload
        if defined?(ActiveSupport::Reloader)
          Rails.application.reloader.reload!
        else
          ActionDispatch::Reloader.prepare!
        end
      end

      begin
        block.call(worker, job)
      ensure
        ActionDispatch::Reloader.cleanup! if reload && !defined?(ActiveSupport::Reloader)
      end
    end
  end

  plugins.each { |plugin| plugin.inject! }
end

Instance Attribute Details

#config ⇒ Object (readonly)

Returns the value of attribute config.



14
15
16
 
# File 'lib/delayed/worker.rb', line 14

def config
  @config
end

#max_priority ⇒ Object (readonly)

Returns the value of attribute max_priority.



14
15
16
 
# File 'lib/delayed/worker.rb', line 14

def max_priority
  @max_priority
end

#min_priority ⇒ Object (readonly)

Returns the value of attribute min_priority.



14
15
16
 
# File 'lib/delayed/worker.rb', line 14

def min_priority
  @min_priority
end

#queue_name ⇒ Object (readonly)

Returns the value of attribute queue_name.



14
15
16
 
# File 'lib/delayed/worker.rb', line 14

def queue_name
  @queue_name
end

#work_queue ⇒ Object (readonly)

Returns the value of attribute work_queue.



14
15
16
 
# File 'lib/delayed/worker.rb', line 14

def work_queue
  @work_queue
end

Class Method Details

.current_job ⇒ Object 



36
37
38
 
# File 'lib/delayed/worker.rb', line 36

def self.current_job
  Thread.current[:running_delayed_job]
end

.lifecycle ⇒ Object 



32
33
34
 
# File 'lib/delayed/worker.rb', line 32

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

.on_max_failures=(block) ⇒ Object

Callback to fire when a delayed job fails max_attempts times. If this callback is defined, then the value of destroy_failed_jobs is ignored, and the job is destroyed if this block returns true.

This allows for destroying “uninteresting” failures, while keeping around interesting failures to be investigated later.

The block is called with args(job, last_exception)



24
25
26
 
# File 'lib/delayed/worker.rb', line 24

def self.on_max_failures=(block)
  @@on_max_failures = block
end

.running_job(job) ⇒ Object 



40
41
42
43
44
45
 
# File 'lib/delayed/worker.rb', line 40

def self.running_job(job)
  Thread.current[:running_delayed_job] = job
  yield
ensure
  Thread.current[:running_delayed_job] = nil
end

Instance Method Details

#cleaned? ⇒ Boolean

Returns:

  • (Boolean) 


162
163
164
 
# File 'lib/delayed/worker.rb', line 162

def cleaned?
  @cleaned
end

#cleanup! ⇒ Object 



152
153
154
155
156
157
158
159
160
 
# File 'lib/delayed/worker.rb', line 152

def cleanup!
  return if cleaned?

  health_check.stop
  work_queue.close
  Delayed::Job.clear_locks!(name)

  @cleaned = true
end

#configure_for_job(job) ⇒ Object

set up the session context information, so that it gets logged with the job log lines also set up a unique tmpdir, which will get removed at the end of the job.



266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
 
# File 'lib/delayed/worker.rb', line 266

def configure_for_job(job)
  previous_tmpdir = ENV['TMPDIR']

  self.class.running_job(job) do
    dir = Dir.mktmpdir("job-#{job.id}-#{self.name.gsub(/[^\w\.]/, '.')}-")
    begin
      ENV['TMPDIR'] = dir
      yield
    ensure
      FileUtils.remove_entry(dir, true)
    end
  end
ensure
  ENV['TMPDIR'] = previous_tmpdir
end

#exit? ⇒ Boolean

Returns:

  • (Boolean) 


96
97
98
 
# File 'lib/delayed/worker.rb', line 96

def exit?
  @exit
end

#handle_failed_job(job, error) ⇒ Object 



245
246
247
248
249
 
# File 'lib/delayed/worker.rb', line 245

def handle_failed_job(job, error)
  job.last_error = "#{error.message}\n#{error.backtrace.join("\n")}"
  logger.error("Failed with #{error.class} [#{error.message}] (#{job.attempts} attempts)")
  job.reschedule(error)
end

#health_check ⇒ Object 



282
283
284
285
286
287
288
 
# File 'lib/delayed/worker.rb', line 282

def health_check
  @health_check ||= HealthCheck.build(
    type: @health_check_type,
    worker_name: name,
    config: @health_check_config
  )
end

#id ⇒ Object 



251
252
253
 
# File 'lib/delayed/worker.rb', line 251

def id
  Process.pid
end

#log_job(job, format = :short) ⇒ Object 



255
256
257
258
259
260
261
262
 
# File 'lib/delayed/worker.rb', line 255

def log_job(job, format = :short)
  case format
  when :long
    "#{job.full_name} #{ Settings.job_detailed_log_format.call(job) }"
  else
    job.full_name
  end
end

#name ⇒ Object 



88
89
90
 
# File 'lib/delayed/worker.rb', line 88

def name
  @name ||= "#{Socket.gethostname rescue "X"}:#{self.id}"
end

#perform(job) ⇒ Object 



200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
 
# File 'lib/delayed/worker.rb', line 200

def perform(job)
  count = 1
  raise Delayed::Backend::JobExpired, "job expired at #{job.expires_at}" if job.expired?
  self.class.lifecycle.run_callbacks(:perform, self, job) do
    set_process_name("run:#{Settings.worker_procname_prefix}#{job.id}:#{job.name}")
    logger.info("Processing #{log_job(job, :long)}")
    runtime = Benchmark.realtime do
      if job.batch?
        # each job in the batch will have perform called on it, so we don't
        # need a timeout around this
        count = perform_batch(job)
      else
        job.invoke_job
      end
      job.destroy
    end
    logger.info("Completed #{log_job(job)} #{"%.0fms" % (runtime * 1000)}")
  end
  count
rescue SystemExit => se
  # There wasn't really a failure here so no callbacks and whatnot needed,
  # still reschedule the job though.
  job.reschedule(se)
  count
rescue Exception => e
  self.class.lifecycle.run_callbacks(:error, self, job, e) do
    handle_failed_job(job, e)
  end
  count
end

#perform_batch(parent_job) ⇒ Object 



231
232
233
234
235
236
237
238
239
240
241
242
243
 
# File 'lib/delayed/worker.rb', line 231

def perform_batch(parent_job)
  batch = parent_job.payload_object
  if batch.mode == :serial
    batch.jobs.each do |job|
      job.source = parent_job.source
      job.create_and_lock!(name)
      configure_for_job(job) do
        perform(job)
      end
    end
    batch.items.size
  end
end

#run ⇒ Object 



166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
 
# File 'lib/delayed/worker.rb', line 166

def run
  return if exit?
  self.class.lifecycle.run_callbacks(:loop, self) do
    set_process_name("pop:#{Settings.worker_procname_prefix}#{@queue_name}:#{min_priority || 0}:#{max_priority || 'max'}")
    job = self.class.lifecycle.run_callbacks(:pop, self) do
      work_queue.get_and_lock_next_available(name, config)
    end

    if job
      configure_for_job(job) do
        @job_count += perform(job)

        if @max_job_count > 0 && @job_count >= @max_job_count
          logger.debug "Max job count of #{@max_job_count} exceeded, dying"
          @exit = true
        end

        if @max_memory_usage > 0
          memory = sample_memory
          if memory > @max_memory_usage
            logger.debug "Memory usage of #{memory} exceeds max of #{@max_memory_usage}, dying"
            @exit = true
          else
            logger.debug "Memory usage: #{memory}"
          end
        end
      end
    else
      set_process_name("wait:#{Settings.worker_procname_prefix}#{@queue_name}:#{min_priority || 0}:#{max_priority || 'max'}")
      sleep(Settings.sleep_delay + (rand * Settings.sleep_delay_stagger)) unless exit?
    end
  end
end

#sample_memory ⇒ Object

generic unix solution



300
301
302
303
 
# File 'lib/delayed/worker.rb', line 300

def sample_memory
  s = File.read("/proc/#{Process.pid}/statm").to_i rescue 0
  s * LINUX_PAGE_SIZE / 1024
end

#set_process_name(new_name) ⇒ Object 



92
93
94
 
# File 'lib/delayed/worker.rb', line 92

def set_process_name(new_name)
  $0 = "delayed:#{new_name}"
end

#start ⇒ Object 



105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
 
# File 'lib/delayed/worker.rb', line 105

def start
  logger.info "Starting worker"
  set_process_name("start:#{Settings.worker_procname_prefix}#{@queue_name}:#{min_priority || 0}:#{max_priority || 'max'}")

  work_thread = Thread.current
  SIGNALS.each do |sig|
    trap(sig) { @signal_queue << sig; wake_up }
  end

  raise 'Could not register health_check' unless health_check.start

  signal_processor = Thread.new do
    loop do
      @self_pipe[0].read(1)
      case @signal_queue.pop
      when :INT, :TERM
        @exit = true # get the main thread to bail early if it's waiting for a job
        work_thread.raise(SystemExit) # Force the main thread to bail out of the current job
        cleanup! # we're going to get SIGKILL'd in a moment, so clean up asap
        break
      when :QUIT
        @exit = true
      else
        logger.error "Unknown signal '#{sig}' received"
      end
    end
  end

  self.class.lifecycle.run_callbacks(:execute, self) do
    until exit? do
      run
    end
  end

  logger.info "Stopping worker"
rescue => e
  Rails.logger.fatal("Child process died: #{e.inspect}") rescue nil
  self.class.lifecycle.run_callbacks(:exceptional_exit, self, e) { }
ensure
  cleanup!

  if signal_processor
    signal_processor.kill
    signal_processor.join
  end
end

#wake_up ⇒ Object 



100
101
102
103
 
# File 'lib/delayed/worker.rb', line 100

def wake_up
  @self_pipe[1].write_nonblock('.', exception: false)
  work_queue.wake_up
end