Class: Delayed::Backend::ActiveRecord::Job

Inherits:
ActiveRecord::Base
  • Object
show all
Includes:
Base
Defined in:
lib/delayed/backend/active_record.rb

Overview

A job object that is persisted to the database. Contains the work object as a YAML field.

Direct Known Subclasses

Failed

Defined Under Namespace

Classes: Failed

Constant Summary

Constants included from Base

Base::ON_HOLD_COUNT, Base::ON_HOLD_LOCKED_BY

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Base

#batch?, #failed?, #full_name, #hold!, included, #initialize_defaults, #invoke_job, #locked?, #name, #on_hold?, #payload_object, #payload_object=, #permanent_failure, #reschedule, #reschedule_at, #unhold!, #unlock

Class Method Details

.all_available(queue = Delayed::Settings.queue, min_priority = nil, max_priority = nil) ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 206

def self.all_available(queue = Delayed::Settings.queue,
                       min_priority = nil,
                       max_priority = nil)
  min_priority ||= Delayed::MIN_PRIORITY
  max_priority ||= Delayed::MAX_PRIORITY

  check_queue(queue)
  check_priorities(min_priority, max_priority)

  self.ready_to_run.
      where(:priority => min_priority..max_priority, :queue => queue).
      by_priority
end

.bulk_update(action, opts) ⇒ Object

perform a bulk update of a set of jobs action is :hold, :unhold, or :destroy to specify the jobs to act on, either pass opts = [list of job ids] or opts = <some flavor> to perform on all jobs of that flavor



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# File 'lib/delayed/backend/active_record.rb', line 139

def self.bulk_update(action, opts)
  scope = if opts[:flavor]
    raise("Can't bulk update failed jobs") if opts[:flavor].to_s == 'failed'
    self.scope_for_flavor(opts[:flavor], opts[:query])
  elsif opts[:ids]
    self.where(:id => opts[:ids])
  end

  return 0 unless scope

  case action.to_s
  when 'hold'
    scope.update_all(:locked_by => ON_HOLD_LOCKED_BY, :locked_at => db_time_now, :attempts => ON_HOLD_COUNT)
  when 'unhold'
    now = db_time_now
    scope.update_all(["locked_by = NULL, locked_at = NULL, attempts = 0, run_at = (CASE WHEN run_at > ? THEN run_at ELSE ? END), failed_at = NULL", now, now])
  when 'destroy'
    scope.delete_all
  end
end

.by_priority ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 70

def self.by_priority
  order("priority ASC, run_at ASC")
end

.clear_locks!(worker_name) ⇒ Object

When a worker is exiting, make sure we don’t have any locked jobs.



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# File 'lib/delayed/backend/active_record.rb', line 75

def self.clear_locks!(worker_name)
  where(:locked_by => worker_name).update_all(:locked_by => nil, :locked_at => nil)
end

.create_singleton(options) ⇒ Object

Create the job on the specified strand, but only if there aren’t any other non-running jobs on that strand. (in other words, the job will still be created if there’s another job on the strand but it’s already running)



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# File 'lib/delayed/backend/active_record.rb', line 233

def self.create_singleton(options)
  strand = options[:strand]
  transaction_for_singleton(strand) do
    job = self.where(:strand => strand, :locked_at => nil).order(:id).first
    new_job = new(options)
    if job
      new_job.initialize_defaults
      job.run_at = [job.run_at, new_job.run_at].min
      job.save! if job.changed?
    else
      new_job.save!
    end
    job || new_job
  end
end

.current ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 46

def self.current
  where("run_at<=?", db_time_now)
end

.failed ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 54

def self.failed
  where("failed_at IS NOT NULL")
end

.find_available(limit, queue = Delayed::Settings.queue, min_priority = nil, max_priority = nil) ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 199

def self.find_available(limit,
                        queue = Delayed::Settings.queue,
                        min_priority = nil,
                        max_priority = nil)
  all_available(queue, min_priority, max_priority).limit(limit).to_a
end

.future ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 50

def self.future
  where("run_at>?", db_time_now)
end

.get_and_lock_next_available(worker_name, queue = Delayed::Settings.queue, min_priority = nil, max_priority = nil) ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 178

def self.get_and_lock_next_available(worker_name,
                                     queue = Delayed::Settings.queue,
                                     min_priority = nil,
                                     max_priority = nil)

  check_queue(queue)
  check_priorities(min_priority, max_priority)

  loop do
    jobs = find_available(Settings.fetch_batch_size, queue, min_priority, max_priority)
    return nil if jobs.empty?
    if Settings.select_random_from_batch
      jobs = jobs.sort_by { rand }
    end
    job = jobs.detect do |job|
      job.send(:lock_exclusively!, worker_name)
    end
    return job if job
  end
end

.jobs_count(flavor, query = nil) ⇒ Object

get the total job count for the given flavor see list_jobs for documentation on arguments



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# File 'lib/delayed/backend/active_record.rb', line 129

def self.jobs_count(flavor,
                    query = nil)
  scope = self.scope_for_flavor(flavor, query)
  scope.count
end

.list_jobs(flavor, limit, offset = 0, query = nil) ⇒ Object

get a list of jobs of the given flavor in the given queue flavor is :current, :future, :failed, :strand or :tag depending on the flavor, query has a different meaning: for :current and :future, it’s the queue name (defaults to Delayed::Settings.queue) for :strand it’s the strand name for :tag it’s the tag name for :failed it’s ignored



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# File 'lib/delayed/backend/active_record.rb', line 118

def self.list_jobs(flavor,
                   limit,
                   offset = 0,
                   query = nil)
  scope = self.scope_for_flavor(flavor, query)
  order = flavor.to_s == 'future' ? 'run_at' : 'id desc'
  scope.order(order).limit(limit).offset(offset).to_a
end

.ready_to_run ⇒ Object

a nice stress test: 10_000.times { |i| Kernel.send_later_enqueue_args(:system, { :strand => ‘s1’, :run_at => (24.hours.ago + (rand(24.hours.to_i))) }, “echo #i >> test1.txt”) } 500.times { |i| “ohai”.send_later_enqueue_args(:reverse, { :run_at => (12.hours.ago + (rand(24.hours.to_i))) }) } then fire up your workers you can check out strand correctness: diff test1.txt <(sort -n test1.txt)



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# File 'lib/delayed/backend/active_record.rb', line 67

def self.ready_to_run
  where("run_at<=? AND locked_at IS NULL AND next_in_strand=?", db_time_now, true)
end

.reconnect! ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 20

def self.reconnect!
  clear_all_connections!
end

.running ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 58

def self.running
  where("locked_at IS NOT NULL AND locked_by<>'on hold'")
end

.running_jobs ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 83

def self.running_jobs()
  self.running.order(:locked_at)
end

.scope_for_flavor(flavor, query) ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 87

def self.scope_for_flavor(flavor, query)
  scope = case flavor.to_s
  when 'current'
    self.current
  when 'future'
    self.future
  when 'failed'
    Delayed::Job::Failed
  when 'strand'
    self.where(:strand => query)
  when 'tag'
    self.where(:tag => query)
  else
    raise ArgumentError, "invalid flavor: #{flavor.inspect}"
  end

  if %w(current future).include?(flavor.to_s)
    queue = query.presence || Delayed::Settings.queue
    scope = scope.where(:queue => queue)
  end

  scope
end

.strand_size(strand) ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 79

def self.strand_size(strand)
  self.where(:strand => strand).count
end

.tag_counts(flavor, limit, offset = 0) ⇒ Object

returns a list of hashes { :tag => tag_name, :count => current_count } in descending count order flavor is :current or :all

Raises:

  • (ArgumentError) 


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# File 'lib/delayed/backend/active_record.rb', line 163

def self.tag_counts(flavor,
                    limit,
                    offset = 0)
  raise(ArgumentError, "invalid flavor: #{flavor}") unless %w(current all).include?(flavor.to_s)
  scope = case flavor.to_s
    when 'current'
      self.current
    when 'all'
      self
    end

  scope = scope.group(:tag).offset(offset).limit(limit)
  scope.order("COUNT(tag) DESC").count.map { |t,c| { :tag => t, :count => c } }
end

.transaction_for_singleton(strand) ⇒ Object

used internally by create_singleton to take the appropriate lock depending on the db driver



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# File 'lib/delayed/backend/active_record.rb', line 222

def self.transaction_for_singleton(strand)
  self.transaction do
    connection.execute(sanitize_sql(["SELECT pg_advisory_xact_lock(half_md5_as_bigint(?))", strand]))
    yield
  end
end

Instance Method Details

#create_and_lock!(worker) ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 281

def create_and_lock!(worker)
  raise "job already exists" unless new_record?
  self.locked_at = Delayed::Job.db_time_now
  self.locked_by = worker
  save!
end

#fail! ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 288

def fail!
  attrs = self.attributes
  attrs['original_job_id'] = attrs.delete('id')
  attrs['failed_at'] ||= self.class.db_time_now
  attrs.delete('next_in_strand')
  self.class.transaction do
    failed_job = Failed.create(attrs)
    self.destroy
    failed_job
  end
rescue
  # we got an error while failing the job -- we need to at least get
  # the job out of the queue
  self.destroy
  # re-raise so the worker logs the error, at least
  raise
end

#lock_strand_on_create ⇒ Object 



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# File 'lib/delayed/backend/active_record.rb', line 40

def lock_strand_on_create
  if strand.present?
    self.class.connection.execute("SELECT pg_advisory_xact_lock(half_md5_as_bigint(#{self.class.sanitize(strand)}))")
  end
end