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On Fri, 8 Feb 2002 jaw+plug@tcp4me.com wrote:
> typically, someone looking for geographically diverse servers has
> one or both of the following goals in mind:
> redundancy in the event of a failure. If a fiber is cut, natural
> disaster, terrorist attack, etc. causes one server to be unable
> to serve data, the other server(s) should take over and continue.
>
> improved end-user experience. By serving data from a server closer
> to the end-user, performance is improved.
>
> both of these are "hard problems" to do well.
>
> the former generally involves hardware or software that monitors the servers
> and re-directs traffic either by re-routing the packets or by changing the
> addresses returned in DNS queries.
>
> the latter is nearly always done with "smart" DNS servers, that return the
> address of the "best" server to use. Determining the "best" server involves
> mapping the Internet topology and calculating metrics, often via BGP, or
> ad-hoc pinging.
It seems that the latter solution is a reasonable solution to both
problems, since a down server (for whatever reason) can be seen as the
lowest of low performance, zero.
> there are also content-delivery companies that you can outsource to. they
> colocate thousands of servers scattered around the world, and have a staff
> of people that analyze BGP sessions mapping the Internet.
Wow, I would think it would have to be almost all automated.
> for further reading: f5.com, akamai.com
Excellent, thank you!
Wayne
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