Failover solution using BGP

[rdobbins at cisco.com (Roland Dobbins)]

On Dec 31, 2008, at 11:36 PM, Florian Weimer wrote:

> DNS tweaks won't help with that (and to be honest, BGP doesn't  
> address it, either).


After all, there ought to be an internal line of communication as well  
as the external one, and the availability probes can be set up with  
logic such that if one side has bidirectional comms and the other  
doesn't, the desired behavior (whatever that may be, dependent upon  
which side has full comms) can be enforced.

Couple that with a stateless front-end - which could also afford  
active/active in that tier, even if the back-end is monolithic - and  
it's more nearly a complete solution, with more options, granularity,  
and safeguards available, than one based upon routing alone.

-----------------------------------------------------------------------
Roland Dobbins <rdobbins at cisco.com> // +852.9133.2844 mobile

      All behavior is economic in motivation and/or consequence.