persistance accross datacenters?

3-DNS can only handle DNS queries not URI's. Regular wideip persitence will allow you to persist an LDNS to a particular data center (though in 4.5 it's to a particular virtual server). Did you try this first?

 

 

You could try issuing a 302 redirect to dc1.url.com/123 or dc2.url.com/456 where dc1 and dc2 are wideip's on the 3-DNS that use pool level global availability to select virtual servers in the appropriate DC. Note: use wideip's to ensure high availability if dc1 dies then dc1.url.com can resolve back to dc2.

Another tool that might be of use is the application { ... } object in 3-DNS (introduced in v4.6.2). It allows you to group together a bunch of wideip objects and then (via a checkbox in the application object) persist all client local-DNSes to the same datacenter for requests to any wideip in the application.

 

 

One example of this is when you have a transaction oriented application that involves the client going through several steps that may involve different services on the back-end, like a web front-end, an authentication server, an application server, and a back-end database. If any one of these pieces of the application dies, 3-DNS can treat the whole collection of services as unavailable and re-resolve local-DNSes to an alternate datacenter where the clients can complete their transactions.

 

 

To take advantage of this you'd still have to ensure the domain names embedded in the URL's were different according to the "sites" or types/groups of content you want to manage, as described by mullet.