SP V3 metadata types

[Cantor, Scott]

> What happens if you take the notion of "high-value entity" to its logical
> conclusion? The concept is really quite simple. Suppose an IdP has access to a
> trusted, remote metadata aggregate containing most of its SP partners. (That's
> a big "IF" but please bear with me as I make my point.) In that case, the tail of
> the provider chain would consist of a FileBackedHTTPMetadataProvider (to
> load the aggregate) followed by a DynamicHTTPMetadataProvider (to pick up
> any stray SPs not in the aggregate). QED

Sure, though obviously that presupposes that file is something you can come up with without just pointing at the aggregate and ending up with a 5 minute startup and 1G of RAM. It would make sense if federations provided a custom aggregate capability, but otherwise I don't see it really happening.

> Such a configuration minimizes the number of times the
> DynamicHTTPMetadataProvider makes a request. If it does fail, it fails on an SP
> that is not a recognized SP partner (since its not in the aggregate).
> 
> As a hypothetical concept, does that make sense?

Sure, in theory, just not really in practice today.

> I was asking about the IdP documentation...if anyone on the dev team thinks
> the wiki example [1] is counterproductive, I will remove it.

I think it's probably not crazy to show in the IdP today, but I've already asked Brent to improve some of the behavior of the dynamic plugin and I think that will render it unnecessary so I would prefer we not complicate examples with it now.

-- Scott