Re: Recursion vs Redirection

[Eric Dean <eric@crystalballinc.com>]

Considering that we are dealing with proxies, I don't think that state
should be a problem 8-)  However, it is this state maching that in fact
becomes extremely valuable; otherwise, if my peered CDN request routing
system fails, I have no knowledge of it unless I periodically poll
them...based upon your polling interval, this could be a considerable
amount of delay.  In addition, the peered request routing system may be
available to you but not routable by the client...an on, and on, ad
nauseum...  I've experienced a bit of trepidation from content provider,
CDN operators and the likes when they understand that we throw the content
delivery "over the wall" to a peered network without any control other
than a second chance when a TTL expires.
 
On Mon, 15 Oct 2001, Oliver Spatscheck wrote:

> 
> Eric,
> 
> 	the only problem with a recursive approach is that it requires changes
> to the existing infrastructure and adds additional overhead to the CDN
> receiving the inital request (For example, if a flash crowed arrives
> the CDN receiving the inital request has to track all the state of the
> outstanding requests to other CDNs etc..). As pointed out before I
> think whatever protocols we come up with should support both.
> 
> Oliver
> 
> 
> Eric Dean writes:
>  >  
>  > A few months ago, I mentioned the concept of using a recursive DNS query
>  > for CDI rather than CNAMEs.  CNAMEs create problems whereby a peered CDN
>  > experiencing QoS problems can adversely affect content requests until a
>  > TTL expiration occurs.  This can create apprehension when a CDN operator 
>  > does not have strict control of a publisher's content.
>  > 
>  > However, CDI via recursive DNS queries that transpose the client's IP
>  > address into the additional section preserves all CDN request routing
>  > information while providing a different level of administrative control.
>  > 
>  >   
>  > Eric Dean
>  > President, Crystal Ball Inc.
>  > W 703-322-8000
>  > F 703-322-8010 
>  > M 703-597-6921 
>  > 
>  > 
>  > 
> 

Eric Dean
President, Crystal Ball Inc.
W 703-322-8000
F 703-322-8010 
M 703-597-6921