Class: MaintenanceTasks::Run Private

Inherits:
ApplicationRecord show all
Defined in:
app/models/maintenance_tasks/run.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Model that persists information related to a task being run from the UI.

Constant Summary collapse

STATUSES =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

Various statuses a run can be in.

[
  :enqueued,    # The task has been enqueued by the user.
  :running,     # The task is being performed by a job worker.
  :succeeded,   # The task finished without error.
  :cancelling,  # The task has been told to cancel but is finishing work.
  :cancelled,   # The user explicitly halted the task's execution.
  :interrupted, # The task was interrupted by the job infrastructure.
  :pausing,     # The task has been told to pause but is finishing work.
  :paused,      # The task was paused in the middle of the run by the user.
  :errored,     # The task code produced an unhandled exception.
]
ACTIVE_STATUSES =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

[
  :enqueued,
  :running,
  :paused,
  :pausing,
  :cancelling,
  :interrupted,
]
STOPPING_STATUSES =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

[
  :pausing,
  :cancelling,
  :cancelled,
]
COMPLETED_STATUSES =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

[:succeeded, :errored, :cancelled]

Instance Method Summary collapse

Instance Method Details

#active? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns whether the Run is active, which is defined as having a status of enqueued, running, pausing, cancelling, paused or interrupted.

Returns:

  • (Boolean) —

    whether the Run is active.



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# File 'app/models/maintenance_tasks/run.rb', line 222

def active?
  ACTIVE_STATUSES.include?(status.to_sym)
end

#cancel ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Cancels a Run.

If the Run is paused, it will transition directly to cancelled, since the Task is not being performed. In this case, the ended_at timestamp will be updated.

If the Run is not paused, the Run will transition to cancelling.

If the Run is already cancelling, and has last been updated more than 5 minutes ago, it will transition to cancelled, and the ended_at timestamp will be updated.



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# File 'app/models/maintenance_tasks/run.rb', line 313

def cancel
  if paused? || stuck?
    self.status = :cancelled
    self.ended_at = Time.now
    persist_transition
  else
    cancelling!
  end
rescue ActiveRecord::StaleObjectError
  reload_status
  retry
end

#complete ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Handles the completion of a Run, setting a status of succeeded and the ended_at timestamp.



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# File 'app/models/maintenance_tasks/run.rb', line 297

def complete
  self.status = :succeeded
  self.ended_at = Time.now
end

#completed? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns whether the Run is completed, which is defined as having a status of succeeded, cancelled, or errored.

Returns:

  • (Boolean) —

    whether the Run is completed.



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# File 'app/models/maintenance_tasks/run.rb', line 213

def completed?
  COMPLETED_STATUSES.include?(status.to_sym)
end

#csv_attachment_presence ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Performs validation on the presence of a :csv_file attachment. A Run for a Task that uses CsvCollection must have an attached :csv_file to be valid. Conversely, a Run for a Task that doesn’t use CsvCollection should not have an attachment to be valid. The appropriate error is added if the Run does not meet the above criteria.



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# File 'app/models/maintenance_tasks/run.rb', line 367

def csv_attachment_presence
  if Task.named(task_name).has_csv_content? && !csv_file.attached?
    errors.add(:csv_file, "must be attached to CSV Task.")
  elsif !Task.named(task_name).has_csv_content? && csv_file.present?
    errors.add(:csv_file, "should not be attached to non-CSV Task.")
  end
rescue Task::NotFoundError
  nil
end

#csv_content_type ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Performs validation on the content type of the :csv_file attachment. A Run for a Task that uses CsvCollection must have a present :csv_file and a content type of “text/csv” to be valid. The appropriate error is added if the Run does not meet the above criteria.



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# File 'app/models/maintenance_tasks/run.rb', line 381

def csv_content_type
  if csv_file.present? && csv_file.content_type != "text/csv"
    errors.add(:csv_file, "must be a CSV")
  end
rescue Task::NotFoundError
  nil
end

#csv_file ⇒ ActiveStorage::Attached::One

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Fetches the attached ActiveStorage CSV file for the run. Checks first whether the ActiveStorage::Attachment table exists so that we are compatible with apps that are not using ActiveStorage.

Returns:

  • (ActiveStorage::Attached::One) —

    the attached CSV file



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# File 'app/models/maintenance_tasks/run.rb', line 410

def csv_file
  return unless defined?(ActiveStorage)
  return unless ActiveStorage::Attachment.table_exists?

  super
end

#enqueued! ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Sets the run status to enqueued, making sure the transition is validated in case it’s already enqueued.

Rescues and retries status transition if an ActiveRecord::StaleObjectError is encountered.



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# File 'app/models/maintenance_tasks/run.rb', line 85

def enqueued!
  status_will_change!
  super
rescue ActiveRecord::StaleObjectError
  reload_status
  retry
end

#job_shutdown ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Handles transitioning the status on a Run when the job shuts down.



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# File 'app/models/maintenance_tasks/run.rb', line 283

def job_shutdown
  if cancelling?
    self.status = :cancelled
    self.ended_at = Time.now
  elsif pausing?
    self.status = :paused
  elsif cancelled?
  else
    self.status = :interrupted
  end
end

#pause ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Marks a Run as pausing.

If the Run has been stuck on pausing for more than 5 minutes, it forces the transition to paused. The ended_at timestamp will be updated.

Rescues and retries status transition if an ActiveRecord::StaleObjectError is encountered.



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# File 'app/models/maintenance_tasks/run.rb', line 333

def pause
  if stuck?
    self.status = :paused
    persist_transition
  else
    pausing!
  end
rescue ActiveRecord::StaleObjectError
  reload_status
  retry
end

#persist_error(error) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Marks the run as errored and persists the error data.

Parameters:

  • error (StandardError) —

    the Error being persisted.



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# File 'app/models/maintenance_tasks/run.rb', line 143

def persist_error(error)
  self.started_at ||= Time.now
  update!(
    status: :errored,
    error_class: truncate(:error_class, error.class.name),
    error_message: truncate(:error_message, error.message),
    backtrace: MaintenanceTasks.backtrace_cleaner.clean(error.backtrace),
    ended_at: Time.now,
  )
  run_error_callback
rescue ActiveRecord::StaleObjectError
  reload_status
  retry
end

#persist_progress(number_of_ticks, duration) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Increments tick_count by number_of_ticks and time_running by duration, both directly in the DB. The attribute values are not set in the current instance, you need to reload the record.

Parameters:

  • number_of_ticks (Integer) —

    number of ticks to add to tick_count.

  • duration (Float) —

    the time in seconds that elapsed since the last increment of ticks.



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# File 'app/models/maintenance_tasks/run.rb', line 126

def persist_progress(number_of_ticks, duration)
  self.class.update_counters(
    id,
    tick_count: number_of_ticks,
    time_running: duration,
    touch: true,
  )
  if locking_enabled?
    locking_column = self.class.locking_column
    self[locking_column] += 1
    clear_attribute_change(locking_column)
  end
end

#persist_transition ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Saves the run, persisting the transition of its status, and all other changes to the object.



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# File 'app/models/maintenance_tasks/run.rb', line 103

def persist_transition
  save!
  callback = CALLBACKS_TRANSITION[status]
  run_task_callbacks(callback) if callback
rescue ActiveRecord::StaleObjectError
  success = succeeded?
  reload_status
  if success
    self.status = :succeeded
  else
    job_shutdown
  end
  retry
end

#reload_status ⇒ MaintenanceTasks::Run

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Refreshes the status and lock version attributes on the Active Record object, and ensures ActiveModel::Dirty doesn’t mark the object as changed.

This allows us to get the Run’s most up-to-date status without needing to reload the entire record.

Returns:



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# File 'app/models/maintenance_tasks/run.rb', line 165

def reload_status
  columns_to_reload = if locking_enabled?
    [:status, self.class.locking_column]
  else
    [:status]
  end
  updated_status, updated_lock_version = self.class.uncached do
    self.class.where(id: id).pluck(*columns_to_reload).first
  end

  self.status = updated_status
  if updated_lock_version
    self[self.class.locking_column] = updated_lock_version
  end
  clear_attribute_changes(columns_to_reload)
  self
end

#running ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Marks a Run as running.

If the run is stopping already, it will not transition to running. Rescues and retries status transition if an ActiveRecord::StaleObjectError is encountered.



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# File 'app/models/maintenance_tasks/run.rb', line 246

def running
  if locking_enabled?
    begin
      running! unless stopping?
    rescue ActiveRecord::StaleObjectError
      reload_status
      retry
    end
  else
    # Preserve swap-and-replace solution for data races until users
    # run migration to upgrade to optimistic locking solution
    return if stopping?

    updated = self.class.where(id: id).where.not(status: STOPPING_STATUSES)
      .update_all(status: :running, updated_at: Time.now) > 0
    if updated
      self.status = :running
      clear_attribute_changes([:status])
    else
      reload_status
    end
  end
end

#start(count) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Starts a Run, setting its started_at timestamp and tick_total.

Parameters:

  • count (Integer) —

    the total iterations to be performed, as specified by the Task.



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# File 'app/models/maintenance_tasks/run.rb', line 274

def start(count)
  update!(started_at: Time.now, tick_total: count)
  task.run_callbacks(:start)
rescue ActiveRecord::StaleObjectError
  reload_status
  retry
end

#started? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns whether the Run has been started, which is indicated by the started_at timestamp being present.

Returns:

  • (Boolean) —

    whether the Run was started.



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# File 'app/models/maintenance_tasks/run.rb', line 205

def started?
  started_at.present?
end

#stopped? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns whether the Run is stopped, which is defined as having a status of paused, succeeded, cancelled, or errored.

Returns:

  • (Boolean) —

    whether the Run is stopped.



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# File 'app/models/maintenance_tasks/run.rb', line 197

def stopped?
  completed? || paused?
end

#stopping? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns whether the Run is stopping, which is defined as having a status of pausing or cancelling. The status of cancelled is also considered stopping since a Run can be cancelled while its job still exists in the queue, and we want to handle it the same way as a cancelling run.

Returns:

  • (Boolean) —

    whether the Run is stopping.



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# File 'app/models/maintenance_tasks/run.rb', line 189

def stopping?
  STOPPING_STATUSES.include?(status.to_sym)
end

#stuck? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns whether a Run is stuck, which is defined as having a status of cancelling or pausing, and not having been updated in the last 5 minutes.

Returns:

  • (Boolean) —

    whether the Run is stuck.



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# File 'app/models/maintenance_tasks/run.rb', line 349

def stuck?
  (cancelling? || pausing?) && updated_at <= MaintenanceTasks.stuck_task_duration.ago
end

#task ⇒ Task

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a Task instance for this Run. Assigns any attributes to the Task based on the Run’s parameters. Note that the Task instance is not supplied with :csv_content yet if it’s a CSV Task. This is done in the job, since downloading the CSV file can take some time.

Returns:

  • (Task) —

    a Task instance.



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# File 'app/models/maintenance_tasks/run.rb', line 423

def task
  @task ||= begin
    task = Task.named(task_name).new
    if task.attribute_names.any? && arguments.present?
      task.assign_attributes(arguments)
    end
    task
  rescue ActiveModel::UnknownAttributeError
    task
  end
end

#task_name_belongs_to_a_valid_task ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Performs validation on the task_name attribute. A Run must be associated with a valid Task to be valid. In order to confirm that, the Task is looked up by name.



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# File 'app/models/maintenance_tasks/run.rb', line 356

def task_name_belongs_to_a_valid_task
  Task.named(task_name)
rescue Task::NotFoundError
  errors.add(:task_name, "must be the name of an existing Task.")
end

#time_to_completion ⇒ ActiveSupport::Duration

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns the duration left for the Run to finish based on the number of ticks left and the average time needed to process a tick. Returns nil if the Run is completed, or if tick_count or tick_total is zero.

Returns:

  • (ActiveSupport::Duration) —

    the estimated duration left for the Run to finish.



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# File 'app/models/maintenance_tasks/run.rb', line 232

def time_to_completion
  return if completed? || tick_count == 0 || tick_total.to_i == 0

  processed_per_second = (tick_count.to_f / time_running)
  ticks_left = (tick_total - tick_count)
  seconds_to_finished = ticks_left / processed_per_second
  seconds_to_finished.seconds
end

#validate_task_arguments ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Performs validation on the arguments to use for the Task. If the Task is invalid, the errors are added to the Run.



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# File 'app/models/maintenance_tasks/run.rb', line 391

def validate_task_arguments
  arguments_match_task_attributes if arguments.present?
  if task.invalid?
    error_messages = task.errors
      .map { |error| "#{error.attribute.inspect} #{error.message}" }
    errors.add(
      :arguments,
      "are invalid: #{error_messages.join("; ")}",
    )
  end
rescue Task::NotFoundError
  nil
end