module Gitlab module BackgroundMigration def self.queue @queue ||= BackgroundMigrationWorker.sidekiq_options['queue'] end # Begins stealing jobs from the background migrations queue, blocking the # caller until all jobs have been completed. # # When a migration raises a StandardError is is going to be retries up to # three times, for example, to recover from a deadlock. # # When Exception is being raised, it enqueues the migration again, and # re-raises the exception. # # steal_class - The name of the class for which to steal jobs. def self.steal(steal_class) enqueued = Sidekiq::Queue.new(self.queue) scheduled = Sidekiq::ScheduledSet.new [scheduled, enqueued].each do |queue| queue.each do |job| migration_class, migration_args = job.args next unless job.queue == self.queue next unless migration_class == steal_class begin perform(migration_class, migration_args) if job.delete rescue Exception # rubocop:disable Lint/RescueException BackgroundMigrationWorker # enqueue this migration again .perform_async(migration_class, migration_args) raise end end end end ## # Performs a background migration. # # class_name - The name of the background migration class as defined in the # Gitlab::BackgroundMigration namespace. # # arguments - The arguments to pass to the background migration's "perform" # method. def self.perform(class_name, arguments) migration_class_for(class_name).new.perform(*arguments) end def self.migration_class_for(class_name) const_get(class_name) end end end