Class: CloudCrowd::Job

Inherits:
ActiveRecord::Base
  • Object
show all
Includes:
ModelStatus
Defined in:
lib/cloud_crowd/models/job.rb

Overview

A chunk of work that will be farmed out into many WorkUnits to be processed in parallel by each active CloudCrowd::Worker. Jobs are defined by a list of inputs (usually public urls to files), an action (the name of a script that CloudCrowd knows how to run), and, eventually a corresponding list of output.

Constant Summary collapse

CLEANUP_GRACE_PERIOD =

That’s a week.

7

Class Method Summary collapse

Instance Method Summary collapse

Methods included from ModelStatus

#complete?, #display_status, #failed?, included, #incomplete?, #merging?, #processing?, #splitting?, #succeeded?

Class Method Details

.cleanup_all(opts = {}) ⇒ Object

Clean up all jobs beyond a certain age.



35
36
37
38
39
40
 
# File 'lib/cloud_crowd/models/job.rb', line 35

def self.cleanup_all(opts = {})
  days = opts[:days] || CLEANUP_GRACE_PERIOD
  self.complete.older_than(days).find_in_batches(:batch_size => 100) do |jobs|
    jobs.each {|job| job.destroy }
  end
end

.create_from_request(h) ⇒ Object

Create a Job from an incoming JSON request, and add it to the queue.



24
25
26
27
28
29
30
31
32
 
# File 'lib/cloud_crowd/models/job.rb', line 24

def self.create_from_request(h)
  self.create(
    :inputs       => h['inputs'].to_json,
    :action       => h['action'],
    :options      => (h['options'] || {}).to_json,
    :email        => h['email'],
    :callback_url => h['callback_url']
  )
end

Instance Method Details

#action_class ⇒ Object

Retrieve the class for this Job’s Action.

Raises:



117
118
119
120
121
 
# File 'lib/cloud_crowd/models/job.rb', line 117

def action_class
  @action_class ||= CloudCrowd.actions[self.action]
  return @action_class if @action_class
  raise Error::ActionNotFound, "no action named: '#{self.action}' could be found"
end

#all_work_units_complete? ⇒ Boolean

Have all of the WorkUnits finished?

Returns:

  • (Boolean) 


92
93
94
 
# File 'lib/cloud_crowd/models/job.rb', line 92

def all_work_units_complete?
  self.work_units.incomplete.count <= 0
end

#any_work_units_failed? ⇒ Boolean

Have any of the WorkUnits failed?

Returns:

  • (Boolean) 


97
98
99
 
# File 'lib/cloud_crowd/models/job.rb', line 97

def any_work_units_failed?
  self.work_units.failed.count > 0
end

#check_for_completion ⇒ Object

After work units are marked successful, we check to see if all of them have finished, if so, continue on to the next phase of the job.



44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/cloud_crowd/models/job.rb', line 44

def check_for_completion
  return unless all_work_units_complete?
  set_next_status
  outs = gather_outputs_from_work_units
  return queue_for_workers([outs]) if merging?
  if complete?
    update_attributes(:outputs => outs, :time => time_taken)
    Thread.new { fire_callback } if callback_url
  end
  self
end

#cleanup_assets ⇒ Object

Cleaning up after a job will remove all of its files from S3 or the filesystem. Destroying a Job will cleanup_assets first. Run this in a separate thread to get out of the transaction’s way. TODO: Convert this into a ‘cleanup’ work unit that gets run by a worker.



87
88
89
 
# File 'lib/cloud_crowd/models/job.rb', line 87

def cleanup_assets
  AssetStore.new.cleanup(self)
end

#color ⇒ Object

Generate a stable 8-bit Hex color code, based on the Job’s id.



143
144
145
 
# File 'lib/cloud_crowd/models/job.rb', line 143

def color
  @color ||= Digest::MD5.hexdigest(self.id.to_s)[-7...-1]
end

#done_splitting? ⇒ Boolean

This job is done splitting if it’s finished with its splitting work units.

Returns:

  • (Boolean) 


107
108
109
 
# File 'lib/cloud_crowd/models/job.rb', line 107

def done_splitting?
  splittable? && work_units.splitting.count <= 0
end

#fire_callback ⇒ Object

If a callback_url is defined, post the Job’s JSON to it upon completion. The callback_url may include HTTP basic authentication, if you like:

http://user:[email protected]/job_complete

If the callback URL returns a ‘201 Created’ HTTP status code, CloudCrowd will assume that the resource has been successfully created, and the Job will be cleaned up.



74
75
76
77
78
79
80
81
 
# File 'lib/cloud_crowd/models/job.rb', line 74

def fire_callback
  begin
    response = RestClient.post(callback_url, {:job => self.to_json})
    Thread.new { self.destroy } if response && response.code == 201
  rescue RestClient::Exception => e
    puts "Job ##{id} failed to fire callback: #{callback_url}"
  end
end

#mergeable? ⇒ Boolean

This job is mergeable if its Action has a merge method.

Returns:

  • (Boolean) 


112
113
114
 
# File 'lib/cloud_crowd/models/job.rb', line 112

def mergeable?
  self.processing? && self.action_class.public_instance_methods.map {|m| m.to_sym }.include?(:merge)
end

#percent_complete ⇒ Object

How complete is this Job? Unfortunately, with the current processing sequence, the percent_complete can pull a fast one and go backwards. This happens when there’s a single large input that takes a long time to split, and when it finally does it creates a whole swarm of work units. This seems unavoidable.



128
129
130
131
132
133
134
 
# File 'lib/cloud_crowd/models/job.rb', line 128

def percent_complete
  return 99  if merging?
  return 100 if complete?
  unit_count = work_units.count
  return 100 if unit_count <= 0
  (work_units.complete.count / unit_count.to_f * 100).round
end

#set_next_status ⇒ Object

Transition this Job’s current status to the appropriate next one, based on the state of the WorkUnits and the nature of the Action.



58
59
60
61
62
63
64
65
 
# File 'lib/cloud_crowd/models/job.rb', line 58

def set_next_status
  update_attribute(:status,
    any_work_units_failed? ? FAILED     :
    self.splitting?        ? PROCESSING :
    self.mergeable?        ? MERGING    :
                             SUCCEEDED
  )
end

#splittable? ⇒ Boolean

This job is splittable if its Action has a split method.

Returns:

  • (Boolean) 


102
103
104
 
# File 'lib/cloud_crowd/models/job.rb', line 102

def splittable?
  self.action_class.public_instance_methods.map {|m| m.to_sym }.include? :split
end

#time_taken ⇒ Object

How long has this Job taken?



137
138
139
140
 
# File 'lib/cloud_crowd/models/job.rb', line 137

def time_taken
  return self.time if self.time
  Time.now - self.created_at
end

#to_json(opts = {}) ⇒ Object

A JSON representation of this job includes the statuses of its component WorkUnits, as well as any completed outputs.



149
150
151
152
153
154
155
156
157
158
159
160
161
 
# File 'lib/cloud_crowd/models/job.rb', line 149

def to_json(opts={})
  atts = {
    'id'                => id,
    'color'             => color,
    'status'            => display_status,
    'percent_complete'  => percent_complete,
    'work_units'        => work_units.count,
    'time_taken'        => time_taken
  }
  atts['outputs'] = JSON.parse(outputs) if outputs
  atts['email']   = email               if email
  atts.to_json
end