[Box Backup] Server redundancy and backup servers

[Ben Summers]

On 24 Sep 2004, at 14:08, rprice@freeshell.org wrote:

> I think it would be a good idea to have the client choose the initial, 
> and
> failover server from the list in a random fashion, and then prefer the
> last server it talked to.
>
> So the algorithm would use the same code whenever it was unable to 
> contact
> the last used server, and in the case of the first run, there would be 
> no
> last used server.
>
> This way you don't have to configure the client to start with a 
> particular
> server, it just works out.

What if you have your primary servers on a really fast connection, but 
with the backup ones at a less desirable location? You might want to 
keep control over where the client will connect to make sure it always 
talks to the primary location.

The list of servers has to be got from somewhere, so you've got to 
configure it with something. So if you want to load-balance it as you 
suggest, just pick a random server when you configure it in the first 
place.

The other problem is what happens in a failure situation. If there are 
four servers, and three go down, then the backup clients will all talk 
to the remaining one for ever more.

Or have I missed the point somewhere? I've tried to devise a scheme 
where the administrator has control over what happens.

Ben