DNS Failover

[Maria Iano]

We use GSLBs for load balancing between web sites but mostly for failover in case a primary site goes down. Usually they work pretty well. It's true that some name servers don't handle TTLs properly, but from my experience at watching the traffic I can tell you that it works for the vast majority. 

Personally I haven't found it to be the case, as stated in the article you mention, that I have to restart my browser for the new A record to take effect. It has been my experience that the browser catches on and goes to the new IP pretty much immediately. The browsers I use most frequently are Firefox, Safari and IE. They are recent versions. Maybe the problems you describe occurred with older versions?...

Maria

> 
> -----Original Message-----
> From: bind-users-bounce at isc.org [mailto:bind-users-bounce at isc.org] On
> Behalf Of Pete Tenereillo
> Sent: Thursday, October 14, 2004 9:00 AM
> To: Greg Maccarone; Anthony Wilkins
> Cc: comp-protocols-dns-bind at isc.org
> Subject: Re: DNS Failover
> 
> Anthony mentioned he has a Web app, so that TTL trick won't work
> reliably. 
> The low TTL would be seen by servers "throughout the rest of the world"
> but 
> TTL are ignored by most clients (and many proxy servers), so all
> existing 
> users (and users that share such proxies) will be stuck on the downed 
> server. Check out:
> 
> http://www.tenereillo.com/GSLBPageOfShame.htm
> 
> for details. IMO for failover you are better off putting both servers at
> the 
> same site, using local load balancing (there are some very cost
> effective 
> solutions available now) and redundant power and Internet connections.
> 
> 
> Pete.
> 
> 
> ----- Original Message ----- 
> From: "Greg Maccarone" <gmaccarone at gmail.com>
> To: "Anthony Wilkins" <anthony_wlkns at yahoo.com>
> Cc: <comp-protocols-dns-bind at isc.org>
> Sent: Tuesday, October 12, 2004 11:46 AM
> Subject: Re: DNS Failover
> 
> 
> > On Tue, 12 Oct 2004 11:01:45 +0200, Anthony Wilkins
> > <anthony_wlkns at yahoo.com> wrote:
> >> Hi, is there anybody who can help me in finding a solution to a
> problem
> >> I have?
> >>
> >> My web server is sometime temporarily down and I want people to go to
> my
> >> remote site where I have a backup web server. Can I change DNS on the
> >> Internet fast enough for incoming requests to be handled by my
> redundant
> >> web server? Normally I don't want traffic to go to the remote site.
> >>
> >> Thanks, Anthony W.
> >>
> >>
> >
> > A way this could be achieved with DNS is to have a low TTL on the host
> > entry that could be changing because of the outage.  Then in most
> > cases it would take no longer than the specified TTL for the changes
> > to be seen throughout the rest of the world.
> >
> > my $.02.
> >
> > -- 
> > Greg Maccarone
> > gmaccarone at gmail.com
> >
> > 
>