We found some entries in centralauth.localuser with lu_global_id and lu_local_id set to null. Is this on purpose? Are there good reasons to keep the data or should we just purge?
(you can see the 3970 accounts, all made sometime between 2008 and 2015 at a glance: select * from localuser where lu_global_id is null;
As Platform Engineering is dead, wondering if this is still MediaWiki-extensions-CentralAuth code connaisseurs or already DBA's (please correct me).
Hm, probably not exactly the same as that task is about 0 not null, and null was supposed to be backfilled while 0 is just wrong, so the difference is relevant.
Null values should have been backfilled by T148242: Fully populate local_user_id and global_user_id fields in production and filled going forward by T142507: Have CentralAuth populate the local_user_id and global_user_id columns as new users are attached; apprently neither works perfectly because we have 3976 values now.