There is a Mediawiki maintenance cron job running:
The full command line is:
command => '/usr/local/bin/foreachwiki maintenance/cleanupUploadStash.php > /dev/null'
So stdout is redirected to /dev/null but stderr is not. The user is <www-data@mwmaint1001>.
Recently we have been getting cron spam from errors like this:
 => Array (  => backend-fail-delete  => mwstore://local-swift-codfw/local-temp/thumb/0/0b/20180819201153!chunkedupload_6f83855c84b5.djvu/page1-230px-20180819201153!chunkedupload_6f83855c84b5.djvu.jpg )
All the messages seem to be about swift-codfw, none about eqiad.
Questions for this ticket:
- How critical / uncommon is this?
- Does it really just affect codfw?
- Is it a bug or a feature that we are getting the emails when there is an error like this. Should stderr also be silenced? Should it be a real monitoring check?
- Why does it fail deleting these files?