[79860] in North American Network Operators' Group
Re: Memory leak cause of Comcast DNS problems
daemon@ATHENA.MIT.EDU (Florian Weimer)
Sun Apr 17 12:29:57 2005
From: Florian Weimer <fw@deneb.enyo.de>
To: Sean Donelan <sean@donelan.com>
Cc: nanog@merit.edu
Date: Sun, 17 Apr 2005 18:29:27 +0200
In-Reply-To: <Pine.GSO.4.58.0504162200300.12002@clifden.donelan.com> (Sean
Donelan's message of "Sat, 16 Apr 2005 22:03:39 -0400 (EDT)")
Errors-To: owner-nanog@merit.edu
* Sean Donelan:
> Perhaps your DNS software also has a memory leak? Anyone know which
> software Comcast was using? Should other ISPs be concerned they might
> have the same latent problem in their systems?
Probably yes, especially if they don't read documentation of their DNS
software.
| The maximum amount of memory to use for the server's cache, in
| bytes. [...] The default is unlimited, meaning that records are
| purged from the cache only when their TTLs expire.
The number of complaints I've heard that "DNS resolvers eat *so* much
memory" suggests that few people tweak the default configuration. 8-(
However, it's unlikely that this was the cause of Comcast's problems
because DNS cache overflows would have an impact on a much larger
scale.
