Date:  Tue, 17 Mar 2009 13:55:42 +0000
From:  "Colin Jack" <colin (at mark) mainline.co.uk>
Subject:  [coba-e:15345] Re: Re  Broken FTP
To:  <coba-e (at mark) bluequartz.org>
Message-Id:  <45DACA7BE1DEA245AF6C95E5B94E531B0D07A62D82 (at mark) datastore.mainline.local>
In-Reply-To:  <49BF9787.5030804 (at mark) virtbiz.com>
References:  <45DACA7BE1DEA245AF6C95E5B94E531B0D07A62D72 (at mark) datastore.mainline.local> <49BF9787.5030804 (at mark) virtbiz.com>
X-Mail-Count: 15345

> > * The FTP server is operating normally.
> >
> > Seeing this about four or five times in 24 hours.
> 
> We have yet to witness this on any server and we run service-level
> monitoring on every one of our hosting boxes at 5 minute intervals.
> 
> This sort of smells DNS'y to me with the off/on-again nature that you're
> describing.  You're not running DNS lookups on your FTP, are you?   How
> is your DNS recursion doing?   Does /var/log/messages show anything odd
> w/ regard to proftpd?
> 
> --
> Chris Gebhardt
> VIRTBIZ Internet Services
> Access, Web Hosting, Colocation, Dedicated
> www.virtbiz.com | toll-free (866) 4 VIRTBIZ

These servers have been rock solid for years (apart from the BO one) ... not running anything like DNS lookups.
Absolutely nothing has changed other than the yum update which updated ProFTPD.
The servers are colocoed at two different data centres.

Nope nothing untoward in the logs.

Colin