gitlab-org--gitlab-foss/db/post_migrate/20190214112022_schedule_sync_issuables_state_id.rb

class ScheduleSyncIssuablesStateId < ActiveRecord::Migration[5.0]
  # This migration schedules the sync of state_id for issues and merge requests
  # which are converting the state column from string to integer.
  # For more information check: https://gitlab.com/gitlab-org/gitlab-ce/issues/51789

  include Gitlab::Database::MigrationHelpers

  DOWNTIME = false

  # 2019-02-12 gitlab.com issuable numbers
  # issues count: 13587305
  # merge requests count: 18925274
  #
  # Using 25000 as batch size should take around 26 hours
  # to migrate both issues and merge requests
  BATCH_SIZE = 25000
  DELAY_INTERVAL = 5.minutes.to_i
  ISSUES_MIGRATION = 'SyncIssuesStateId'.freeze
  MERGE_REQUESTS_MIGRATION = 'SyncMergeRequestsStateId'.freeze

  class Issue < ActiveRecord::Base
    include EachBatch

    self.table_name = 'issues'
  end

  class MergeRequest < ActiveRecord::Base
    include EachBatch

    self.table_name = 'merge_requests'
  end

  def up
    Sidekiq::Worker.skipping_transaction_check do
      queue_background_migration_jobs_by_range_at_intervals(Issue.where(state_id: nil),
                                                            ISSUES_MIGRATION,
                                                            DELAY_INTERVAL,
                                                            batch_size: BATCH_SIZE
                                                           )

      queue_background_migration_jobs_by_range_at_intervals(MergeRequest.where(state_id: nil),
                                                            MERGE_REQUESTS_MIGRATION,
                                                            DELAY_INTERVAL,
                                                            batch_size: BATCH_SIZE
                                                           )
    end
  end

  def down
    # No op
  end
end