Add cleanup migration for MR's mutliple assignees

The migration steals the remaining background jobs
of populating MRs with assignees, executes them
synchronously and then makes sure that all the
assignees are migrated

1 files changed, 20 insertions, 0 deletions

diff --git a/db/post_migrate/20190702173936_populate_remaining_merge_request_assignees.rb b/db/post_migrate/20190702173936_populate_remaining_merge_request_assignees.rb
new file mode 100644
index 00000000000..c435b94015d
--- /dev/null
+++ b/db/post_migrate/20190702173936_populate_remaining_merge_request_assignees.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class PopulateRemainingMergeRequestAssignees < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  BATCH_SIZE = 10_000
+  MIGRATION = 'PopulateMergeRequestAssigneesTable'
+
+  disable_ddl_transaction!
+
+  def up
+    Gitlab::BackgroundMigration.steal(MIGRATION)
+
+    Gitlab::BackgroundMigration::PopulateMergeRequestAssigneesTable.new.perform_all_sync(batch_size: BATCH_SIZE)
+  end
+end