[netmod] kw review of draft-liu-netmod-yang-schedule

[Kent Watsen <[e-mail]>]

[As a contributor]

While it's clear what this document is trying to achieve at a high level, it is unclear why the solution is needed.   A "motivation" section explaining why this should be standardized would be nice.

When reading this draft, I was reminded of my long expired draft https://tools.ietf.org/html/draft-kwatsen-conditional-enablement-00.  That draft provided a more general solution, in that it enabled sub-trees to be enabled/disabled for any reason.  It was primarily focused on supporting comments, but it did call out that expressions could include time, though it didn't flush out that thought to any extent.

Other than draft-kwatsen-conditional-enablement being a more generic solution, another difference is that this draft enables the module-designer to specify where in the data model the grouping is used, whereas my old draft let the client enabled/disabled nodes anywhere in the data model, potentially producing nonsensical results, though we have to assume that the server would fail any invalid results.

Regarding this solution, I have some specific questions:

1) why is the "schedule" node a list?  How is a list to be processed?   Are there any overlapping issues?

2) does the "schedule-id" leaf have any useful purpose other than being the list's key?

3) the "schedule-duration" node's pattern matches XSD's "duration" type, is it the intent to process it as such?

4) the draft-ietf-netconf-server-model draft originally had a duration-like value, but the WG consensus was at the time was to instead use an unsigned integer value with a "units" value (e.g., seconds, minutes, etc.).  The claim was that, when large values where needed (e.g., 3600-seconds instead of 1-hour), that the client could always do the math.  Any thoughts on that?

5) are there any issues with the "repeat-interval" node?  I'm specifically thinking about the interval being expressed in terms of hours and days in the context of daylight savings and leap year...


Nit: some examples in the draft would've been nice.

Thanks,
Kent