Let's say I have a website and I don't want it to have downtime...

Let's say it's hosted on 3 different servers.


Is it possible to automatically switch the user on the fastest server.. and a server goes down the others will guarantee uptime?!?!?


Thanks,

Marco.

Marco,

Really, the only right way to do what you want is to use a hardware load balancer, or something like the Linux Virtual Server Project:

http://www.linuxvirtualserver.org/

Sorry but I haven't understood if it's possible to have no downtime by splitting on different servers..


Marco.

Actually, Travis did pretty much answer your question. The answer : yes, it's theoretically (and I think very) possible, but you would need to use one of the solutions Travis suggested.

Is it possible to have 4 IPs. The first 2 would point to Server A and the second 2 to Server B. If Server A was down, would the domain then direct to server B??

Thanks

Yeah, you can basically have 4 A records in your DNS. But then you better make sure your DNS doesn't go down so I guess you should have 4 redundant DNS servers.

Is it possible to have 4 IPs. The first 2 would point to Server A and the second 2 to Server B. If Server A was down, would the domain then direct to server B??

This is interesting. I am not sure this would work. It is not like MX records where you set a priority. How are the name servers checking priory? I hate DNS, too much mental gymnastics.

The only sure way to get close to 100% uptime is to do what some of the big boys do. Geographical load balancing. Put your site on numerous servers across multiple data centers with different back bones. Have these load balancers check each other for the fastest route for a visitor and for uptime. Webhosting.com and ***** have this for example. It is not cheap.

We use the same idea on IRCd's, the address irc.domainhere.com is an A record for each server, and us, ca, uk, and other country abriviations are setup like us.domainhere.com for each us server as an A record, and the finally we have servername.us.domainhere.com as an A record for that server alone. It allows us to keep the network balanced out.....

Hope I wasn't to confusing on that explaination...

Originally posted by The Prohacker
We use the same idea on IRCd's, the address irc.domainhere.com is an A record for each server, and us, ca, uk, and other country abriviations are setup like us.domainhere.com for each us server as an A record, and the finally we have servername.us.domainhere.com as an A record for that server alone. It allows us to keep the network balanced out.....

Hope I wasn't to confusing on that explaination...

But when a server goes down it still sends requests to that server which does not give you 100% uptime or at least close to. It pretty much does the same thing though.

For Web Servers I would get a load balancer or order a managed load balancing service from your hosting company. The managed service would be the cheaper way of doing things. If you can find a copy of Web Hosting Magazine (www.whmag.com) they had a report on load balancers and compared them in price/features/etc. Very good article.