1 files changed, 40 insertions, 0 deletions
diff --git a/db/post_migrate/20170627101016_schedule_event_migrations.rb b/db/post_migrate/20170627101016_schedule_event_migrations.rb
new file mode 100644
index 00000000000..1f34375ff0d
--- /dev/null
+++ b/db/post_migrate/20170627101016_schedule_event_migrations.rb
@@ -0,0 +1,40 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class ScheduleEventMigrations < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  BUFFER_SIZE = 1000
+
+  disable_ddl_transaction!
+
+  class Event < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'events'
+  end
+
+  def up
+    jobs = []
+
+    Event.each_batch(of: 1000) do |relation|
+      min, max = relation.pluck('MIN(id), MAX(id)').first
+
+      if jobs.length == BUFFER_SIZE
+        # We push multiple jobs at a time to reduce the time spent in
+        # Sidekiq/Redis operations. We're using this buffer based approach so we
+        # don't need to run additional queries for every range.
+        BackgroundMigrationWorker.perform_bulk(jobs)
+        jobs.clear
+      end
+
+      jobs << ['MigrateEventsToPushEventPayloads', [min, max]]
+    end
+
+    BackgroundMigrationWorker.perform_bulk(jobs) unless jobs.empty?
+  end
+
+  def down
+  end
+end