During the June 2021 DC switchover, tr.wikivoyage.org was briefly unavailable because in codfw the sectionsByLoad entry was typoed: https://gerrit.wikimedia.org/r/c/operations/mediawiki-config/+/702136/
Given that wikis are expected to be in the same section in both datacenters (please correct if wrong DBA), the two lists should never fall out of sync.
Possible ways to resolve this bug (non-exhaustive):
- Implement a test to verify the two lists are the same
- Move the lists to a db-common.php file that is used by both DCs
- Automate generation of the lists from the dblists.
Marking as high priority because this caused a small outage.