Re: Last Call: <draft-ietf-netmod-revised-datastores-09.txt> (Network Management Datastore Architecture) to Proposed Standard configuration

[Robert Wilton <rwilton@xxxxxxxxx>]

Hi Tom,

The draft uses this definition for configuration:

   o  configuration: Data that is required to get a device from its
      initial default state into a desired operational state.  This data
      is modeled in YANG using "config true" nodes.  Configuration can
      originate from different sources.

The last sentence means that it encompasses configuration that comes from other sources such as protocol interactions.  I.e. by different sources it means that configuration may come via DHCP, or be learned from a peer protocol (e.g. hello timer values, Ethernet auto-negotiation settings).

The other sentence that is key is 'This data is modeled in YANG using "config true" nodes.'.  This statement applies both ways.  If you want to model configuration in YANG then it must be labelled "config true".  Hence all nodes in the schema marked as "config true" are by definition, configuration.  Conversely, all nodes in the schema not marked as "config true" are by definition, not configuration.

So, I don't think that the definition for "configuration" changes through the definitions at all, it has the same meaning through out, i.e. the broader definition that encompasses data learned from other sources such as DHCP, peer protocols, etc, as well as conventional configuration received via NETCONF/RESTCONF or similar "regular" configuration protocols.

I think that the intent of "conventional configuration" probably matches your narrower definition of "configuration" that you describe below:

Thanks,
Rob

On 09/01/2018 16:38, tom p. wrote:

This I-D re-arranges the tectonic plates which underly the IETF's
management technology and is likely to affect all such work for some
years to come.  As such, I want it to be clear and unambiguous but do
not find it so.  I find it unclear as to the meaning of the word
'configuration'.

Netconf (and latterly YANG) were instigated to facilitate configuration,
which was narrowly defined as the values that a user might want to
change to get a box from its initial state to its desired state.  What
might have been thought as configuration historically - values learnt
from hardware or the interactions of protocols - was not configuration
but state, latterly referred to as operational state.  This narrow
definition of configuration is reflected in this I-D.

However, working through the 24 definitions that appear under
'Terminology', while the early ones use this narrow definition, by the
time
we get to

"learned configuration: Configuration that has been learned via protocol
interactions "
or

"system configuration: Configuration that is supplied by the device
itself."
the meaning has clearly changed to encompass all the different ways in
which a device can learn a value i.e 'learned configuration' and 'system
configuration' are not configuration as has been understood up until now
in this work.

I think it hard to follow this I-D when this key term seems to have a
variable meaning. I am uncertain what meaning to attribute the word when
it appears in the later text.

Tom Petch

----- Original Message -----
From: "The IESG" <iesg-secretary@xxxxxxxx>
Sent: Thursday, December 21, 2017 7:23 PM

The IESG has received a request from the Network Modeling WG (netmod)

to

consider the following document: - 'Network Management Datastore

Architecture'

  <draft-ietf-netmod-revised-datastores-09.txt> as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits

final

comments on this action. Please send substantive comments to the
ietf@xxxxxxxx mailing lists by 2018-01-10. Exceptionally, comments may

be

sent to iesg@xxxxxxxx instead. In either case, please retain the

beginning of

the Subject line to allow automated sorting.

Abstract


   Datastores are a fundamental concept binding the data models

written

   in the YANG data modeling language to network management protocols
   such as NETCONF and RESTCONF.  This document defines an

architectural

   framework for datastores based on the experience gained with the
   initial simpler model, addressing requirements that were not well
   supported in the initial model.  This document updates RFC 7950.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-netmod-revised-datastores/

IESG discussion can be tracked via

https://datatracker.ietf.org/doc/draft-ietf-netmod-revised-datastores/ba
llot/

No IPR declarations have been submitted directly on this I-D.

.