Failed to read PID from file /var/run/MailScanner.pid: Invalid argument

[Walt Thiessen]

We had an incident where MailScanner mysteriously stopped running 
yesterday, and we had to restart it.

The only thing my admins could find in the logs to give us any clue as 
to why it stopped was this entry:

Oct 21 23:07:45 server systemd: Failed to read PID from file 
/var/run/MailScanner.pid: Invalid argument

The file at /var/run/MailScanner.pid merely contains a number: 26969, 
and nothing else.

To compound our confusion, that entry came roughly 5 hours after the 
restart.

Does anyone know the purpose of that /var/run/MailScanner.pid and why it 
might generate such an error?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mailscanner.info/pipermail/mailscanner/attachments/20161022/e379db9a/attachment.html>