Re: analysis of YANG vs. RELAX NG

[Balazs Lengyel <[e-mail]>]

Hello Rohan,
Some questions/answers below.
Balazs

Rohan Mahy wrote:
> Hi,
> 
> Comments inline.
> 
> On Nov 28, 2007 8:04 AM, Balazs Lengyel <[e-mail] 
> <mailto:[e-mail]>> wrote:
> 
>     Hello,
>     I am no expert in RelaxNg but here are some thoughts why I like Yang
>     better.
> 
>     I have the feeling once you extend RelaxNg with all the necessary
>     bits, half your statements
>     will start with <other:xxx>. 
> 
> 
> We will never know unless we try the exercise. It seems you are However, I see a pretty small number
> of additional semantic items you list below:
> - an indicator of a default value (if any)
> - a flag that indicates whether a subtree is atomic for edit-config
> - an indicator that the schema is an rpc method and what its matching 
> request or response is
> - a flag that indicates whether a subtree is configuration or 
> operational data (read-write or read-only).
[BALAZS]: Please add
- what does a default value mean for operation data?
- a flag stating if a part of configuration is current, deprecated, obsolete
- a flag indicating if a bit of writable data is stored in non-volatile storage
- information indicating whether the sort order in a list is set by the user or the managed system
- a number of documentation options. And it is not enough to just say documentation, we need 
separate tags/elements for description, contact, revision info etc.
- enterprise specific extensions, do you need to define them or just use them
- formal descriptions of constraint e.g. if encryption method is non-null then we need a password
- references between different parts of the model e.g. this subscriber should use XXX 
application server. And simple ID based referencing is not enough as I want to state that here 
you can only reference application servers but not DNS servers.
- how do you handle data models with multiple roots, that are not well formed XML. (This is a 
current, existing customer demand not a theoretical question.)
- how do you refer to managed object instances e.g. a the observed speed of interface eth0
- etc.

-- 
Balazs Lengyel                       Ericsson Hungary Ltd.
TSP System Manager
ECN: 831 7320                        Fax: [phone]
Tel: [phone]     email: [e-mail]