[Nml-wg] XML Examples and Proposals

[Jason Zurawski]

Hi Jeroen/All;

On 3/13/12 1:45 AM, thus spake Jeroen van der Ham:
> Hi,
>
> On 12 Mar 2012, at 21:23, Jason Zurawski wrote:
>>
>> This still seems like a lifetime to me:
>>
>>> <nml:topo id="freekishnet">
>>>     <lifetime>
>>>       <start>Sun Mar 11 13:25:33 EDT 2012</start>
>>>       <end>Mon Mar 12 17:20:00 EDT 2012</end>
>>>     </lifetime>
>>>     <!-- awesome stuff -->
>>> </nml:topo>
>>>
>>> <nml:topo id="freekishnet">
>>>     <lifetime>
>>>       <start>Mon Mar 12 17:20:00 EDT 2012</start>
>>>       <!-- lack of end or duration means current? -->
>>>     </lifetime>
>>>     <!-- more awesome stuff -->
>>> </nml:topo>
>>
>> It becomes explicit that one has a shelf life, and the other is ongoing.  With 'version' you are left with an arbitrary mark that something is different (and it may be the case that its a date, but it could be just '1' or '2a').  If we see the later being more common, I suppose the use case is different and in this case we may want both to be allowed.
>>
>
> While we so far have not shied away from verbose solutions, the above is way too verbose for my liking. In your proposal, when I announce a new topology, I have to send the old one with an ended lifetime, and also the new one with a lifetime element, with just a start.

I don't see this as 'sending' anything, its a bookeeping step the same 
as creating a new topology.  The amount of work (and verbosity) is 
similar to any other operation.

> Version numbers have worked for DNS, I see no reason why this would be any different.

Clarify this - is 'version' just something that lives on the 'topology' 
element, or is version something that all elements now contain?  Can we 
version nodes (e.g. a switch got a firmware update, or new ports added), 
or links, or ports, or anything else in our universe?

> At the same time, Lifetime does have a valid use for describing reservations, virtual machines, or crossconnects. This use of Lifetime to me is a completely different meaning than versioning topologies. A reservation ceases to exist after its end-time. A topology is not something that usually has an intended lifetime, it is, and may be updated in the future.

I have always rejected ideas that don't add 'new' information.  I don't 
see version as adding anything new that lifetime doesn't already 
feature.  Unless there is a compelling new use case that has not been 
described yet, I remain unconvinced that its vastly different.

Thanks;

-jason