First of all, I don't know if this belongs here, but it could be because the servers I'm going to discuss work with Apache. So...
I'm about to start a new project and there is a hosting issue that has been discussed about mirroring the servers and having some backup.
A different team is proposing a mirroring option that has server A with one hosting provider and server B with another provider. They are working on a solution that will detect when server A is down so it can redirect to server B.
At first glance I'm not sure that's possible. At least what I think I know is that both servers would need to be within the same network or else, how can one domain work for two different DNS.
I've been doing some research and so far have come empty handed and was wondering if someone here could have some other input regarding this issue we are facing.
Well, I'll try to clarify it a little bit more. (even for me)
Server A (SA) will be with hosting provider A (HPA).
Server B (SB) will be with hosting provider B (HPB).
Each server has the website and the database installed. SA is supposed to be the primary server and SB would just be there as a backup.
First, there should be some sort of process that is updating the database in SB.
So, when, and if, SA goes down, people entering the site should be redirected to SB, that it has, or should have, the database updated, so for visitors this redirection is "transparent".
Our question is if that idea of how it should work can be done through proxys, or load balancers, or just through DNS settings (the domain pointing to several IPs from different servers).
That is what I use to mirror my site, which is on the excellent 50webs hosts. The mirror is my localhost, my home machine. I had to replace my hard drive a couple of months ago, it only took about two hours to install, replace and setup the server mirror.