Geo: After DB went down and back up, large number of ProjectImportScheduleWorker jobs ran

Early today the GPRD PostgreSQL node rebooted and PostgreSQL didn't come up automatically (gitlab-com/migration#415 (moved)). After it was manually started, I saw a spike of ProjectImportScheduleWorker jobs that failed to run due to an UPDATE attempt on the Geo read-only database:

As far as I can tell, ProjectImportScheduleWorker is usually instantiated by UpdateAllMirrorsWorker. It looks like there was only these log messages logged 4 hours beforehand: