But the result is the same. So, you're failing over 2 nameservers at each location instead of 1. TTL sill still come into play with external DNS' caching the results prior to failover.
Also, keep in mind, some DNS don't play well an don't honor your TTL's. I think I understand what you're trying to accomplish, and it might work to some degree, and would be better than nothing, but it isn't really ideal, or even less than ideal... Even if you had short TTL's, and external DNS honored the TTL's, it would be very inefficient to have your DNS hammered from increased queries because of the short TTL's... Just my .02. Michael J. Colvin NorCal Internet Services www.norcalisp.com > -----Original Message----- > From: South Computers [mailto:[email protected]] > Sent: Sunday, May 30, 2010 5:50 PM > To: [email protected] > Subject: Re: [qmailtoaster] Opinions Please > > To clarify, ns1 would *not* failover to ns2. Both ns1 & ns2 would > failover to a second set of ns1 & ns2's (duplicate but with different > records). > > > South Computers wrote: > > Thanks, > > > > Yes, that is always the problem with dns failover. But I have to say, > > it has worked extremely well with the paid service I use for the > > critical domains on a domain by domain basis. I think they just set > > the ttl very low. To keep it simple, what I'm thinking it that rather > > than pay for the service for hundreds of domains (I do a lot of > > affiliate marketing), maybe do it for the dns of the actual > > nameservers at the locations (both ns1 & ns2), so IPs for them (my > > nameservers) would change on the fly as an outage occurs for both ns1 > > & ns2. Naturally, both sets of nameservers would publish the IP > > addresses of the web servers for their own location only. > > > > > > Michael J. Colvin wrote: > >> If I follow you right, the biggest issue would be the TTL of the DNS > >> records. If you're using ns1, and everything resolves to the addresses > >> contained in it at location 1, then if failover occurs to ns2, and > >> thus site > >> 2, that would work for "new" requests for DNS information. But, cached > >> information, which is usually at least an hour or more, would still > >> try to > >> resolve to the old IP's. If site 1 is down, then traffic bound for > >> site 1 > >> (Cached requests) would fail. > >> > >> I may not have understood what you were trying to say though.. > >> > >> Mike > >> > >> -----Original Message----- > >> From: South Computers [mailto:[email protected]] Sent: Sunday, > >> May 30, 2010 11:17 AM > >> To: [email protected] > >> Subject: Re: [qmailtoaster] Opinions Please > >> > >> That looks interesting. > >> > >> Been thinking about this myself a lot lately (failover, not load > >> balancing, especially for http). Being in hurricane alley I think > >> about this this time every year. Not too worried about mail, as I > >> just use smtp routes to point everything back to primary mail > server(s). > >> > >> I use dnsmadeeasy's failover services for my "must be up" sites, but > >> wondering.. I have a sneaky idea. Maybe. > >> > >> Might I be cheating a bit if I were to: > >> > >> Setup a couple of domains on dnsmadeeasy (or any service that does > >> failover reliably), and add failover service to each. > >> Add records for ns1, ns2, whatever to each. > >> > >> Setup a dns server on each machine (different geographical locations). > >> > >> Each dns server would be configured to point to it's own set of > >> records (for that location) > >> > >> Setup failover for ns1, ns2, etc at failover dns service to rollover > >> to the live dns server, thus effectively "failovering" all records > >> for everything on the dns server. > >> > >> With hundreds of domains, this could save a lot of money paying for > >> individual failover service. > >> > >> Does this make sense? > >> > >> Thoughts? > >> > >> > >> > >> Scott Hughes wrote: > >> > >>> I am considering setting up a second QMT server using Jake's > >>> replicated server tutorial. These servers will be in two different > >>> cities for maximum redundancy. If I remember correctly, Jake > >>> mentioned setting up DNS round robin to balance the two QMT servers. > >>> > >>> My question is this: Is DNS better for load balancing, or would it > >>> be better to utilize a load balancing program like 'balance' > >>> (http://www.inlab.de/balance.html) ? Or does it really make a > >>> difference for this application. I would be balancing IMAP (993) / > >>> SMTP (25) / POP3 (110). > >>> > >>> Thanks, > >>> > >>> Scott > >>> > >>> > >> > >> > >> ----------------------------------------------------------------------- > ----- > >> > >> ----- > >> Qmailtoaster is sponsored by Vickers Consulting Group > >> (www.vickersconsulting.com) > >> Vickers Consulting Group offers Qmailtoaster support and > >> installations. > >> If you need professional help with your setup, contact them > today! > >> ----------------------------------------------------------------------- > ----- > >> > >> ----- > >> Please visit qmailtoaster.com for the latest news, updates, and > >> packages. > >> To unsubscribe, e-mail: > >> [email protected] > >> For additional commands, e-mail: > >> [email protected] > >> > >> > >> > >> > >> ----------------------------------------------------------------------- > ---------- > >> > >> Qmailtoaster is sponsored by Vickers Consulting Group > >> (www.vickersconsulting.com) > >> Vickers Consulting Group offers Qmailtoaster support and > >> installations. > >> If you need professional help with your setup, contact them > today! > >> ----------------------------------------------------------------------- > ---------- > >> > >> Please visit qmailtoaster.com for the latest news, updates, and > >> packages. > >> To unsubscribe, e-mail: > >> [email protected] > >> For additional commands, e-mail: > >> [email protected] > >> > >> > >> > >> > >> > > > > > > ------------------------------------------------------------------------ > --------- > > > > Qmailtoaster is sponsored by Vickers Consulting Group > > (www.vickersconsulting.com) > > Vickers Consulting Group offers Qmailtoaster support and > > installations. > > If you need professional help with your setup, contact them today! > > ------------------------------------------------------------------------ > --------- > > > > Please visit qmailtoaster.com for the latest news, updates, and > > packages. > > To unsubscribe, e-mail: > > [email protected] > > For additional commands, e-mail: > > [email protected] > > > > > > > > > > > -------------------------------------------------------------------------- > ------- > Qmailtoaster is sponsored by Vickers Consulting Group > (www.vickersconsulting.com) > Vickers Consulting Group offers Qmailtoaster support and > installations. > If you need professional help with your setup, contact them today! > -------------------------------------------------------------------------- > ------- > Please visit qmailtoaster.com for the latest news, updates, and > packages. > > To unsubscribe, e-mail: qmailtoaster-list- > [email protected] > For additional commands, e-mail: qmailtoaster-list- > [email protected] > --------------------------------------------------------------------------------- Qmailtoaster is sponsored by Vickers Consulting Group (www.vickersconsulting.com) Vickers Consulting Group offers Qmailtoaster support and installations. If you need professional help with your setup, contact them today! --------------------------------------------------------------------------------- Please visit qmailtoaster.com for the latest news, updates, and packages. To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
