Performance Degradation: Network Settings page takes ~5 mins to load on large Multisite (250+ sites)

[vmandali001]

We are experiencing a significant performance issue when accessing the Authorizer settings page at the Network Admin level (/wp-admin/network/admin.php?page=authorizer). The page takes approximately 5 minutes to render or respond.

Environment:

• WordPress Version: 6.8.3

• Plugin Version: 3.13.4

• Multisite Setup: Yes

• Network Scale: 250+ sub-sites

• Total Users: ~800 users

Steps to Reproduce:

• Log in as a Network Administrator.

• Navigate to Network Admin > Settings > Authorizer.

• Observe the loading time (currently clocking in at ~300 seconds).

[figureone]

Hm, that almost sounds like the server is hitting a timeout of some kind. Is Authorizer configured to use a CAS server? If the server is having trouble reaching the CAS server it may hang in the admin_notices filter, waiting for the server to respond: https://github.com/uhm-coe/authorizer/blob/master/src/authorizer/class-admin-page.php#L255-L262

Another thing to check is whether any pending database migrations have failed to complete, and are trying to re-run on every reload. Check the wp_options table for the auth_version option_name to have a value of 20230222, if it's lower than that, the migrations in class-updates.php are still trying to run, potentially failing due to PHP memory limits with a large multisite.

If neither of those two things apply, we can continue to profile and see what the issue is!