From 53744bf146f157ee1ecfc9ba4de9e5d65fa80784 Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Wed, 4 Sep 2024 11:43:43 -0400
Subject: [PATCH] Limit the number of orphaned to delete at 100 every 10 mins
 due to the cascading queries that have to check oauth_authorizations and
 oauth_tokens tables.

This should keep ahead of most app registration spam and not overwhelm lower powered servers.
---
 config/config.exs             |  2 +-
 lib/pleroma/web/o_auth/app.ex | 13 +++++++++----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index 2bc28b2561..80a3b8d57f 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -598,7 +598,7 @@
   crontab: [
     {"0 0 * * 0", Pleroma.Workers.Cron.DigestEmailsWorker},
     {"0 0 * * *", Pleroma.Workers.Cron.NewUsersDigestWorker},
-    {"0 0 * * *", Pleroma.Workers.Cron.AppCleanupWorker}
+    {"*/10 * * * *", Pleroma.Workers.Cron.AppCleanupWorker}
   ]
 
 config :pleroma, Pleroma.Formatter,
diff --git a/lib/pleroma/web/o_auth/app.ex b/lib/pleroma/web/o_auth/app.ex
index 6ae419d090..0320114332 100644
--- a/lib/pleroma/web/o_auth/app.ex
+++ b/lib/pleroma/web/o_auth/app.ex
@@ -166,9 +166,14 @@ def maybe_update_owner(%Token{app_id: app_id, user_id: user_id}) when not is_nil
 
   def maybe_update_owner(_), do: :ok
 
-  @spec remove_orphans() :: :ok
-  def remove_orphans() do
-    from(a in __MODULE__, where: is_nil(a.user_id))
-    |> Repo.delete_all()
+  @spec remove_orphans(pos_integer()) :: :ok
+  def remove_orphans(limit \\ 100) do
+    Repo.transaction(fn ->
+      from(a in __MODULE__, where: is_nil(a.user_id), limit: ^limit)
+      |> Repo.all()
+      |> Enum.each(&Repo.delete(&1))
+    end)
+
+    :ok
   end
 end