[Nmc-wg] Review of documents

[Jason Zurawski]

Hi Freek;


> My main point of criticism is that I do not (yet) understand why this
> protocol was developed; as a naive reader it seems to highly overlap
> with what has been done with WSDL. Unfortunately, I'm not an expert on
> either, so I might miss the point. WSDL was developed as a generic
> request-response protocol framework, and so is "Extensible Protocol for
> NMC".
> 
> I still like the work, for example the idea on metadata is good. I just
> recommend to (a) build more on existing frameworks (e.g. specify that
> the protocol MUST use webservices instead of SHOULD, and refer to
> WS-whatever for authentication extension) and (b) make it more clear
> what was added.


Thank you for these comments, I will record them on the TODO lists. 
Regarding the issue of 'why nmc' instead of something like WSDL, the 
idea was sprung from the original use case of encoding measurements. 
The rationale at the time was if we were using an encoding scheme for 
the measurements, wrapping a similarly constructed control structure 
around each for communication was not a far stretch and may even make 
the job of parsing and interpreting the information easier.


> While I'm not very familiar with RELAX-NG, I think it is a good way
> forward, as it can be translated to XSD, and hopefully, this means there
> can be automated syntax check for messages. Has this been done so far?


In practice services don't implement a strict schema check since it can 
be expensive, but the tools exist for both major implementations to do 
this.


> Last, the wording could be better in some places, especially when it
> comes to the RFC 2119 words (MUST, SHOULD, MAY). Two examples: "MAY or
> MAY NOT" (page 6), and my favourite: "Data MUST contain information,
> especially if it was empty in the initial request". Beside the
> obviousness of this statement (what else then information?) and the
> unclarity where "it" refers to, it seems that "SHOULD" was intended
> here, not MUST (why else the "especially"?).


It would be very helpful if you could go through and correct these 
mistakes as you see them - particularly since you have experience in 
writing documents of this nature.  May I mark you down as willing to do 
this task?

Thanks;

-jason