Class: Sidekiq::Processor

Inherits:
Object
  • Object
show all
Includes:
Util
Defined in:
lib/sidekiq/processor.rb

Overview

The Processor is a standalone thread which:

  1. fetches a job from Redis

  2. executes the job

a. instantiate the Worker
b. run the middleware chain
c. call #perform

A Processor can exit due to shutdown (processor_stopped) or due to an error during job execution (processor_died)

If an error occurs in the job execution, the Processor calls the Manager to create a new one to replace itself and exits.

Defined Under Namespace

Classes: Counter

Constant Summary collapse

PROCESSED =
Counter.new
FAILURE =
Counter.new
WORKER_STATE =

This is mutable global state but because each thread is storing its own unique key/value, there's no thread-safety issue AFAIK.

{}

Constants included from Util

Util::EXPIRY

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Util

#fire_event, #hostname, #identity, #logger, #process_nonce, #redis, #safe_thread, #watchdog

Methods included from ExceptionHandler

#handle_exception

Constructor Details

#initialize(mgr) ⇒ Processor


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# File 'lib/sidekiq/processor.rb', line 32

def initialize(mgr)
  @mgr = mgr
  @down = false
  @done = false
  @job = nil
  @thread = nil
  @strategy = (mgr.options[:fetch] || Sidekiq::BasicFetch).new(mgr.options)
  @reloader = Sidekiq.options[:reloader]
  @logging = (mgr.options[:job_logger] || Sidekiq::JobLogger).new
  @retrier = Sidekiq::JobRetry.new
end

Instance Attribute Details

#jobObject (readonly)

Returns the value of attribute job


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# File 'lib/sidekiq/processor.rb', line 30

def job
  @job
end

#threadObject (readonly)

Returns the value of attribute thread


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# File 'lib/sidekiq/processor.rb', line 29

def thread
  @thread
end

Instance Method Details

#cloned(thing) ⇒ Object

Deep clone the arguments passed to the worker so that if the job fails, what is pushed back onto Redis hasn't been mutated by the worker.


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# File 'lib/sidekiq/processor.rb', line 230

def cloned(thing)
  Marshal.load(Marshal.dump(thing))
end

#constantize(str) ⇒ Object


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# File 'lib/sidekiq/processor.rb', line 234

def constantize(str)
  names = str.split('::')
  names.shift if names.empty? || names.first.empty?

  names.inject(Object) do |constant, name|
    # the false flag limits search for name to under the constant namespace
    #   which mimics Rails' behaviour
    constant.const_defined?(name, false) ? constant.const_get(name, false) : constant.const_missing(name)
  end
end

#dispatch(job_hash, queue) ⇒ Object


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# File 'lib/sidekiq/processor.rb', line 118

def dispatch(job_hash, queue)
  # since middleware can mutate the job hash
  # we clone here so we report the original
  # job structure to the Web UI
  pristine = cloned(job_hash)

  Sidekiq::Logging.with_job_hash_context(job_hash) do
    @retrier.global(pristine, queue) do
      @logging.call(job_hash, queue) do
        stats(pristine, queue) do
          # Rails 5 requires a Reloader to wrap code execution.  In order to
          # constantize the worker and instantiate an instance, we have to call
          # the Reloader.  It handles code loading, db connection management, etc.
          # Effectively this block denotes a "unit of work" to Rails.
          @reloader.call do
            klass  = constantize(job_hash['class'])
            worker = klass.new
            worker.jid = job_hash['jid']
            @retrier.local(worker, pristine, queue) do
              yield worker
            end
          end
        end
      end
    end
  end
end

#execute_job(worker, cloned_args) ⇒ Object


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# File 'lib/sidekiq/processor.rb', line 184

def execute_job(worker, cloned_args)
  worker.perform(*cloned_args)
end

#fetchObject


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# File 'lib/sidekiq/processor.rb', line 98

def fetch
  j = get_one
  if j && @done
    j.requeue
    nil
  else
    j
  end
end

#get_oneObject


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# File 'lib/sidekiq/processor.rb', line 87

def get_one
  begin
    work = @strategy.retrieve_work
    (logger.info { "Redis is online, #{Time.now - @down} sec downtime" }; @down = nil) if @down
    work
  rescue Sidekiq::Shutdown
  rescue => ex
    handle_fetch_exception(ex)
  end
end

#handle_fetch_exception(ex) ⇒ Object


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# File 'lib/sidekiq/processor.rb', line 108

def handle_fetch_exception(ex)
  if !@down
    @down = Time.now
    logger.error("Error fetching job: #{ex}")
    handle_exception(ex)
  end
  sleep(1)
  nil
end

#kill(wait = false) ⇒ Object


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# File 'lib/sidekiq/processor.rb', line 50

def kill(wait=false)
  @done = true
  return if !@thread
  # unlike the other actors, terminate does not wait
  # for the thread to finish because we don't know how
  # long the job will take to finish.  Instead we
  # provide a `kill` method to call after the shutdown
  # timeout passes.
  @thread.raise ::Sidekiq::Shutdown
  @thread.value if wait
end

#process(work) ⇒ Object


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# File 'lib/sidekiq/processor.rb', line 146

def process(work)
  jobstr = work.job
  queue = work.queue_name

  ack = false
  begin
    # Treat malformed JSON as a special case: job goes straight to the morgue.
    job_hash = nil
    begin
      job_hash = Sidekiq.load_json(jobstr)
    rescue => ex
      handle_exception(ex, { :context => "Invalid JSON for job", :jobstr => jobstr })
      # we can't notify because the job isn't a valid hash payload.
      DeadSet.new.kill(jobstr, notify_failure: false)
      ack = true
      raise
    end

    ack = true
    dispatch(job_hash, queue) do |worker|
      Sidekiq.server_middleware.invoke(worker, job_hash, queue) do
        execute_job(worker, cloned(job_hash['args']))
      end
    end
  rescue Sidekiq::Shutdown
    # Had to force kill this job because it didn't finish
    # within the timeout.  Don't acknowledge the work since
    # we didn't properly finish it.
    ack = false
  rescue Exception => ex
    e = ex.is_a?(::Sidekiq::JobRetry::Skip) && ex.cause ? ex.cause : ex
    handle_exception(e, { :context => "Job raised exception", :job => job_hash, :jobstr => jobstr })
    raise e
  ensure
    work.acknowledge if ack
  end
end

#process_oneObject


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# File 'lib/sidekiq/processor.rb', line 81

def process_one
  @job = fetch
  process(@job) if @job
  @job = nil
end

#runObject


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# File 'lib/sidekiq/processor.rb', line 68

def run
  begin
    while !@done
      process_one
    end
    @mgr.processor_stopped(self)
  rescue Sidekiq::Shutdown
    @mgr.processor_stopped(self)
  rescue Exception => ex
    @mgr.processor_died(self, ex)
  end
end

#startObject


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# File 'lib/sidekiq/processor.rb', line 62

def start
  @thread ||= safe_thread("processor", &method(:run))
end

#stats(job_hash, queue) ⇒ Object


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# File 'lib/sidekiq/processor.rb', line 212

def stats(job_hash, queue)
  tid = Sidekiq::Logging.tid
  WORKER_STATE[tid] = {:queue => queue, :payload => job_hash, :run_at => Time.now.to_i }

  begin
    yield
  rescue Exception
    FAILURE.incr
    raise
  ensure
    WORKER_STATE.delete(tid)
    PROCESSED.incr
  end
end

#terminate(wait = false) ⇒ Object


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# File 'lib/sidekiq/processor.rb', line 44

def terminate(wait=false)
  @done = true
  return if !@thread
  @thread.value if wait
end