[79902] in North American Network Operators' Group
Re: Memory leak cause of Comcast DNS problems
daemon@ATHENA.MIT.EDU (Eric A. Hall)
Sun Apr 17 23:44:14 2005
Date: Sun, 17 Apr 2005 23:43:43 -0400
From: "Eric A. Hall" <ehall@ehsco.com>
To: Sean Donelan <sean@donelan.com>
Cc: nanog@merit.edu
In-Reply-To: <Pine.GSO.4.58.0504162200300.12002@clifden.donelan.com>
Errors-To: owner-nanog@merit.edu
On 4/16/2005 10:03 PM, Sean Donelan wrote:
> Should other ISPs be concerned they might have the same latent problem
> in their systems?
"ps v -C <server-process-name>" will tell you how badly you're hurting
Anybody that does a bunch of lookups -- whether this is forward lookups
for customers or blacklist lookups on mail or whatever -- is probably
using more than they think. I don't know of many directly related crash
scenarios but there are other penalties like shallow caching which aren't
entirely trivial.
The churning strategy employed is the question that doesn't get answered.
Some servers do FIFO, some do random discards, some use swap space... This
whole area is treated like the embarrassing aunt in the cellar.
--
Eric A. Hall http://www.ehsco.com/
Internet Core Protocols http://www.oreilly.com/catalog/coreprot/
