I have 3 sites in a standalone multisite setup and recently noticed that only one of them is actually performing the scheduled backup.
There does not appear to be anything in the logs about the other sites failing to backup. The unicorn.stdout.log shows only the one site being backed up. A manual backup of all sites works fine.
It seems to have stopped working around the time I updated from 1.4 to 1.5 (on 1.6 now but no change).
The cancel_scheduled_job call in ScheduleBackup is different to the others I found in that it doesn’t supply any args.
My WAG is that perhaps each RailsMultisite iteration in the base scheduler is cancelling the previous scheduled backup leaving only the last one to run?!
While the issue was not related to that commit (the bug was present before), it got me to the right point: we were indeed canceling jobs for all the sites on a multisite install…