Re: [cobalt-users] [RAQ] Redundant Servers

[Jeff Lasman <jblists@xxxxxxxxxxxxx>]

Dennis wrote:

> What if I did this. Instead of adding a secondary nameservice record in
> RaQb I created a site identical to the one on RaQa. Named it the same
> and put it on an IP resolving to RaQb. Then created A records for
> testing.com to point to that IP address.
> 
> Heres the Question:
> Now if RaQa goes down since the secondary nameserver routes the site to
> a different IP will the site come up on RaQb?

Yes and no...

New DNS requests will go to the secondary box, see the info on it, and
connect to the second server.  But DNS, once cached, is there for a
while (on the RaQ3 TTL is settable, on the RaQ2 it defaults to a day, I
believe).  So if one Earthlink customer, for example, found it this
morning on machine a, then machine a went down, everyone else from
Earthlink who wants to find the site for the next 24 hours (longer if
Earthlink, as do some larger ISPs, ignores TTL) will continue to look at
machine a.  New requests will find the site on machine b, though.

Jeff
-- 
Jeff Lasman <jblists@xxxxxxxxxxxxx>
nobaloney.net
P. O. Box 52672
Riverside, CA  92517
voice: (909) 787-8589  *  fax: (909) 782-0205