Re: POST vs. separate methods

On Tue, 29 Oct 1996, Larry Masinter wrote:

> I was thinking more of a return header from ANY request that
> identified a set of other URLs whose cache entries should be marked
> stale. So, if you POST a new entry to
> 
>        http://host.dom/container
> 
> you might get back a return header that it updated:
> 
> 	http://host.dom/container/3q96/by-date
> 	http://host.dom/container/3q96/by-author
> 
> or (even)
> 	http://host.dom/container/3q96/*
> 
> This puts the computational burden on the update method rather than
> retrieval, and is predicated on an assumption that reads happen far
> more frequently than writes.
> 
> Larry
> 

I like the idea of placing the burden on the update method (this sounds a
lot like write-through) but I don't see how this method can guarantee that
a returned entity is up to date. The most obvious problem is that an update
can traverse an entirely different set of caches than a previous GET, thus
allowing for the possibility that some caches would not yet be aware that
its cache entry for the resource is stale. Of course, it everything works
fine as long as both paths hit the same cache at some point.


---
Gregory Woodhouse     gjw@wnetc.com
home page:            http://www.wnetc.com/
resource page:        http://www.wnetc.com/resource/

Received on Tuesday, 29 October 1996 12:20:26 UTC