Isn't there always a single point of failure if you are expecting to be 
able to resolve an http URI via the HTTP protocol?

Whether it's purl.org or not, there's always a single point of failure 
on a given http URI that you expect to resolve via HTTP, the entity 
operating the web server at the specified address. Right?

Now, if you have a collection of disparate http URIs, you have _many_ 
points of failure in that collection. Any entity goes down or ceases to 
exist, and the http URIs that resolved to that entity's web server will 
stop working.

I'd actually rather have a _single_ point of failure, in an organization 
that resources are being put into to ensure persistence, then hundreds 
or thousands of points of failure, many of which are organizations that 
may lack the mission, funding, or understanding to provide reliable 
persistence.

Jonathan



Mike Taylor wrote:
> Ross Singer writes:
>  > Ray, you are absolutely right.  These would be bad identifiers.  But
>  > let's say they're all identical (which I think is what you're saying,
>  > right?), then this just strengthens the case for indirection through a
>  > service like purl.org.  Then it doesn't *matter* that all of these are
>  > different locations, there is one URI that represent the concept of
>  > what is being kept at these locations.  At the end of the redirect can
>  > be some sort of 300 response that lets the client pick which endpoint
>  > is right for them -or arbitrarily chooses one for them.
>
> I have to say I am suspicious of schemes like PURL, which for all
> their good points introduce a single point of failure into, well,
> everything that uses them.  That can't be good.  Especially as it's
> run by the same compary that also runs the often-unavailable OpenURL
> registry.
>
>  _/|_	 ___________________________________________________________________
> /o ) \/  Mike Taylor    <[log in to unmask]>    http://www.miketaylor.org.uk
> )_v__/\  "I don't really think that the end can be assessed as of itself,
> 	 as being the end, because what does the end feel like?  It's like
> 	 trying to extrapolate the end of the universe.  lf the universe
> 	 is indeed infinite, then what does that mean?  How far is all
> 	 the way?  And then if it stops, what's stopping it and what's
> 	 behind what's stopping it?  So 'What is the end?' is my question
> 	 to you" -- David St. Hubbins, _This Is Spinal Tap_.
>
>