Re: [xml-dev] Web Service: SOAP or {HTML + Servlets}?

[Mark Baker <distobj@acm.org>]

> 
> > TSpaces (like CORBA, RMI, DCOM, JavaSpaces, Web Services) is great behind
> > the firewall, but for internet based interactions a document-centric tuple
> > spaces approach is more practical.
> 
> >From the TSpaces FAQ:
> - How an XML document is saved?
> It is divided up at the server into a bunch of tuples corresponding to the
> DOM tree.
> 
> - Can I query the TSpaces server for nodes in the DOM tree?
> Yes, you can. You will receive them back as tuples.
> 
> Why is this (treating a document as DOM nodes) not a "document-centric tuple
> spaces approach"?

I would agree that a document is a kind of tuple, and can be used as such
by tuple space systems such as TSpaces.

I don't believe TSpaces is suitable for internet based interactions,
because although all components share a generic interface, that interface
was not designed to be secure, nor was it designed to scale in important
ways.  A TSpaces method that demonstrates both points is read().  There
is no requirement that the it not change the state of the tuple space,
meaning that invoking it could have undesirable security implications. 
Also, indexing the current state of all spaces would be impractical if
an indexer (like Google) didn't have a safe method from which to examine
the state of those spaces.  Plus, caching of tuples would be impossible
if read() itself invalidated caches (as it would have to as it currently
stands).

HTTP GET is read() done right.

MB