1 files changed, 43 insertions, 0 deletions
diff --git a/db/post_migrate/20200204113223_schedule_recalculate_project_authorizations.rb b/db/post_migrate/20200204113223_schedule_recalculate_project_authorizations.rb
new file mode 100644
index 00000000000..83b58300115
--- /dev/null
+++ b/db/post_migrate/20200204113223_schedule_recalculate_project_authorizations.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+class ScheduleRecalculateProjectAuthorizations < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  MIGRATION = 'RecalculateProjectAuthorizations'
+  BATCH_SIZE = 2_500
+  DELAY_INTERVAL = 2.minutes.to_i
+
+  disable_ddl_transaction!
+
+  class Namespace < ActiveRecord::Base
+    include ::EachBatch
+
+    self.table_name = 'namespaces'
+  end
+
+  class ProjectAuthorization < ActiveRecord::Base
+    include ::EachBatch
+
+    self.table_name = 'project_authorizations'
+  end
+
+  def up
+    say "Scheduling #{MIGRATION} jobs"
+
+    max_group_id = Namespace.where(type: 'Group').maximum(:id)
+    project_authorizations = ProjectAuthorization.where('project_id <= ?', max_group_id)
+                                                 .select(:user_id)
+                                                 .distinct
+
+    project_authorizations.each_batch(of: BATCH_SIZE, column: :user_id) do |authorizations, index|
+      delay = index * DELAY_INTERVAL
+      user_ids = authorizations.map(&:user_id)
+      BackgroundMigrationWorker.perform_in(delay, MIGRATION, [user_ids])
+    end
+  end
+
+  def down
+  end
+end