Re: [netmod] WGLC - draft-ietf-netmod-yang-tree-diagrams

Hi,

I agree with all of Benoit's points below.

On 13/01/2018 14:08, Benoit Claise wrote:
> Hi Tom,
>
> IMO, the best to proceed is exactly like done in the RIP draft.
> Some sections 2.* explains how the module was build, based one 
> excerpts of the tree diagram.
Yes, smaller chunks of tree output can be very useful to explain parts 
of the model.

> Then we have the full tree if someone wants to see the big structure.
Yes, personally, I think that it is probably useful to have the full 
tree output as a reference (probably even if it is 10 pages long). If it 
is particularly long then it would be better put into an appendix.

>
> In the end, the tree view should be browsed with tooling.
> https://datatracker.ietf.org/doc/draft-ietf-rtgwg-yang-rip/
>    => Yang catalog entry for ietf-rip@2018-01-09.yang 
> <https://www.yangcatalog.org/yang-search/module_details.php?module=ietf-rip@2018-01-09.yang>
>    => [Tree View for ietf-rip] Tree View 
> <https://www.yangcatalog.org/yang-search/yang_tree.php?module=ietf-rip>
+1, having a GUI interface into YANG modules (and the combined YANG tree 
with all standard YANG models augmented together) seems like it should 
be the future.

>
>
> Regards, Benoit
>> I think that the outstanding issue is what to do with long tree
>> diagrams. Yes, we have discussed it and have a statement about one page
>> being a good idea but very few of the I-Ds I see can manage that.
>>
>> RIP has four pages, NAT has six.  OSPF and BFD have divided the diagram
>> up but many if not most of the subdivisions still exceed one page (I
>> would regard two as more or less ok but many exceed that).
>>
>> My own take is that a too long tree diagram reflects a too flat module
>> structure, just as many years ago, code would be a long unbroken
>> sequence and now is divided up into manageable modules, so a YANG module
>> should be structured as smaller pieces, bite-size chunks, and a tree
>> diagram of one page is a good indicator of a manageable chunk size.
I think its hard to judge whether a module is too flat or not.

I'm more concerned that YANG groupings make it easy to repeat large 
chunks of YANG in multiple places in a module tree, and I'm not 
convinced that this is always the right thing to do.  Sometimes it may 
be better to add a layer of indrection to avoid the need to reuse the 
same large chunk of YANG in multiple places in the tree. Of course, this 
is all highly subjective ...

Thanks,
Rob

>>
>> Tom Petch
>>
>> ----- Original Message -----
>> From: "joel jaeggli"<joelja@bogus.com>
>> Sent: Monday, January 01, 2018 10:01 PM
>>
>> Greetings,
>>
>> We hope  the new year is a time to make great progess on outstanding
>> documents before preparation for the  London IETF begins in earnest.
>>
>> This starts a two-week working group last call on:
>>
>>   YANG Tree Diagrams
>> draft-ietf-netmod-yang-tree-diagrams
>>
>> https://datatracker.ietf.org/doc/draft-ietf-netmod-yang-tree-diagrams/
>>
>> Please send email to the list indicating your support or concerns.
>>
>> We are particularly interested in statements of the form:
>>
>>    * I have reviewed this draft and found no issues.
>>    * I have reviewed this draft and found the following issues: ...
>>
>>
>> Thank you,
>> NETMOD WG Chairs
>>
>>
>>
>>
>>
>>
>>
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