Fix member expiration not always working

The Sidekiq job `RemoveExpiredMembersWorker` was failing to run in
production because it was hitting statement timeouts because it was
scanning all rows in order. On staging, where it used to scan 4 million
rows, adding an index brought this down to only a few hundred rows.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/67286

1 files changed, 17 insertions, 0 deletions

diff --git a/db/migrate/20190912061145_add_index_to_members_on_expires_at.rb b/db/migrate/20190912061145_add_index_to_members_on_expires_at.rb
new file mode 100644
index 00000000000..e961977747b
--- /dev/null
+++ b/db/migrate/20190912061145_add_index_to_members_on_expires_at.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class AddIndexToMembersOnExpiresAt < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :members, :expires_at
+  end
+
+  def down
+    remove_concurrent_index :members, :expires_at
+  end
+end