1 files changed, 29 insertions, 0 deletions
diff --git a/db/post_migrate/20170628080858_migrate_stage_id_reference_in_background.rb b/db/post_migrate/20170628080858_migrate_stage_id_reference_in_background.rb
new file mode 100644
index 00000000000..ebec4cb6bb7
--- /dev/null
+++ b/db/post_migrate/20170628080858_migrate_stage_id_reference_in_background.rb
@@ -0,0 +1,29 @@
+class MigrateStageIdReferenceInBackground < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  BATCH_SIZE = 10000
+  MIGRATION = 'MigrateBuildStageIdReference'.freeze
+
+  disable_ddl_transaction!
+
+  class Build < ActiveRecord::Base
+    self.table_name = 'ci_builds'
+  end
+
+  def up
+    index = 1
+
+    Build.where(stage_id: nil).in_batches(of: BATCH_SIZE) do |relation|
+      jobs = relation.pluck(:id).map { |id| [MIGRATION, [id]] }
+      schedule = index * 2.minutes
+      index += 1
+
+      BackgroundMigrationWorker.perform_bulk_in(schedule, jobs)
+    end
+  end
+
+  def down
+    # noop
+  end
+end