Bind - one pc,two ips ,two dns servers

[Christopher Chan]

Res wrote:
> On Mon, 1 Dec 2008, Christopher Chan wrote:
> 
>> Heh. Glad you tried to support your claims of my lack of skill/knowledge
>> in running a BIND caching service with a souped up dual Xeon 3Ghz box
>> loaded with RAM in your other post.
>>
>> My guesstimates for 24k queries/sec came from having six mail servers,
>> each configured to handle 800 connections. The actual figure could well
>> be much higher.
>           or lower...
> 
> I know exactly who you are Chris (from another list) and have done for 
> some years, and my comment stands, if you cant do 83K queries p/sec, 
> on same hardware with zero effort, there is a problem somewhere...

Oh really? I don't really mind if you 'expose' me. Go on. I'd like to 
know if I am who you think I am because I don't remember exchanging 
emails with you...

Oh, yeah there is a problem...with BIND. Nothing out there beats DJB's 
dnscache and I don't think that has changed in the last three years 
after I left my job at a service provider. I am more than certain that 
dnscache on a HP DL360 with 4G of RAM would be able to handle all the 
mailservers (see below)

> 
> Oh and *only* 6 mail servers? :)

:-). 4 sets of servers banging away at 4 dnscache boxes. So really just 
twenty-something frontline mailservers. Total 200 million smtp 
transactions handled daily with 40 million mailboxes. Three years ago.

> and so I trust you dont run a copy of your favourite caching DNS server 
> on each then, or you use forward first to it... It might be interesting to 
> shut bind down on all our mail servers falling back to cust1 and see what 
> happens on top of customer traffic, those years old G3's do SFA work, but 
> they exceed the 5 years use life of our internal policies, might as well 
> let em go out with a bang.

Nope, I needed the cpu cycles and them mailserver boxes used to have 
their own local dns cache chewing up 15% of all cpu when the boxes were 
fully loaded but with only 600 connections setup.

> 
>> The dns caching box assigned to handle that load has two paltry Pentium
>> III 800Mhz cpus and a mere 1 GB of RAM. dnscache handles them without a
> 
> Thats rather ancient, I cant recall any figures from that far back, too 
> many years ago, so I wont challenge you on those specs.
> 
> 

You'd have to work in an environment where you don't get new hardware 
and have to squeeze every last drop of juice from your available 
hardware to have to do what I did. Them dnscache boxes were constantly 
pegging one of the cpus to do their job. Load that makes dnscache peg a 
box will most probably knock BIND senseless on that box.