Say I have two different hosting accounts at two different web hosts. One at host1.com and another at host2.com. In both the hosts I keep the same files. I use an external registrar and use the name servers for one of my domains as follows: ns1.host1.com ns2.host1.com ns1.host2.com ns2.host2.com What would happen in that case, if say host1 is down sometime? Will the name servers point to host2.com? If this could work, then the probability of downtime of a site would become almost zero. If this won't work, is there any other solution that can serve the same purpose?
Ya i think. 2 servers 1 website, i think this can reduce the downtime to almost zero if, and only if the servers are good.
I was just about to ask the very same damn question. Maybe Sammas47 and I have the same host, lol. Cause all my sites are down right now. I love my reseller hosting account. It's cheap and the customer service is amazing. They'll help me with almost anything and usually in a couple hours time. That being said there are some downtime issues. Not much, but enough to bother me when I want to work and when I'm promoting via PPC. Will this method work? If DNS Setting #1 is down will the browser automatically show DNS setting # 2? Also, I guess this would be good because you wouldn't really have to worry about site back up. Although having to ftp to two servers every time might be a pain in the ass. Surely there is a solution out there already for this seemingly common problem.
It's working if your site is static. It's not if your site is dynamic with database, and database is not the same in 2 hosts. DNS is working randomly. It's not going ns1 -> ns2 -> ns3, etc. So, at a time, customer requests reach your ns1.host1 first, the content will be updated into host1. But later, other customer requests reach your ns1.host2, the content will be updated into host2. So, you will have 2 different websites
DNS servers only translate (resolve) a domain name to that domain's IP address. The DNS server does not know if your website is down, and can only provide one IP address per domain. If you want to improve the availability of your web site, you will need some failover system that intercepts requests and redirects them to a responsive server. Multiple DNS servers provide redundancy and solely increase the reliability of domain name-to-IP address translation. Most companies use between 2 and 7 DNS servers. If you have an additional DNS server on a different continent, it will probably speed the process of getting an IP address to a requestor on that same continent.
I had very similar questions, as I'm looking to do the same. What I did was contact the folks at dnsmadeeasy. I haven't signed up yet for their service (but will be shortly), but it sounds like thats what you need to accomplish your task. They are also very cheap, compared to UltraDNS (which is cool too but out of my budget).
timocampo, I was not aware of the availability of such inexpensive DNS failover services. (I believe Akamai's rates start at $1500/month.) I will definitely look into DNS Made Easy's offerings. I have an unlimited domain hosting plan at GoDaddy, which means there is no extra cost for additional hosted websites. My Lunarpages hosting fee is $7.00/month. Adding the cost of DNS Made Easy's service, I could probably get much improved availability for less than $15/month. Thanks for the useful information!
On the subject of money, it's not really worth paying $15 per month for another DNS server unless you are currently losing $15 per month due to downtime caused by the DNS server not responding. Remember that DNS is quite heavily cached and the cache usually lasts 24 hours (you can customise this in your DNS setup) If somebody else on my ISP has looked at your site in the last 24 hours then I will be able to resolve your domain's IP address even if your DNS server is down. Peace of mind can be worth more than $15 per month but I suspect the money would be better spent on more likely causes of outages.
I agree with everything in the above post, but I am trying to address slightly different issues such as failover. There are free secondary DNS services that are very reliable. For a very modest fee, you can get multi-continent secondary DNS services and improve the speed and availability of domain name resolution worldwide. Those of us on inexpensive shared hosting services have no control over TTL settings. I'm sure that most web hosting companies offering free DNS service want to minimize their DNS traffic, so as you described, we're out of luck until the cache is refreshed and our server is running. If you can control the TTL of your DNS response, you may be able to get a refreshed IP address every 5 minutes. Re failover, I don't think it will be an effective solution for 1-4 minute outages. However, it should be very effective in eliminating most/all outages greater than 10 minutes. (I'm currently looking into DNS Made Easy's service.)