Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I know this is a bad "solution", if its even one, but due to the circumstances I think it fits.

If Server A runs ns1.example.com and Server 2 runs ns2.example.com and both are hosting an exact duplicate of a website but each have www.example.com DNS A records pointing to themselves. Will this work as a cheap/fast (to setup) failover solution in case server A suddenly fails?

The way I see it, a downtime of 30min-1hr is of no real concern so DNS TTL can be adjusted around that time.

share|improve this question
    
What are you asking, will it cover a DNS failure or a website failure? –  NickW Mar 11 at 17:00
    
website failure –  user1400757 Mar 11 at 17:12

2 Answers 2

up vote 2 down vote accepted

Will this work as a cheap/fast (to setup) failover solution

Not really.

DNS Round Robin is not really a failover or HA solution. It's more of a load balancing solution. If one of the servers fail, about half the requests to your website may also fail until the record of the offline server is first removed from the DNS server and then you have to wait for the TTL value to expire after it is removed and wait for the end systems to clear it out of their cache.

edit: If you are looking to setup both NS servers to serve the same zone with different records, that is likely a non-starter.

share|improve this answer
    
yeah was about to comment on Nick's post about that, now that I'm looking into it you are right –  user1400757 Mar 11 at 17:17
    
If these are external sites, there are fairly inexpensive providers that can do DNS record failover where they update the A record with a very short TTL to a different address when they detect a failure on one of the servers. It's not load balanced, but it would be straight failover. Amazon ROute 53 would be about $2/month for this, DNSMadeEasy would be $30/year + $2/month for the failover add-on (disclaimer: prices might increase depending on the number or queries/zones/etc and is subject to change :) –  Rex Mar 11 at 17:20
    
wow thanks!! that would save me some time :) –  user1400757 Mar 11 at 17:23

Round robin DNS usually requires that both servers offer up both A records, as having multiple authoritative DNS servers which will present different zones to a single client is a no go, at the very least from an administrative standpoint, and very probably from an RFC standpoint.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.