Shepherd writeup
draft-ietf-netconf-yang-push-25

As required by RFC 4858, this is the current template for the Document 
Shepherd Write-Up.

Changes are expected over time. This version is dated 24 February 2012.

(1) What type of RFC is being requested (BCP, Proposed Standard,
Internet Standard, Informational, Experimental, or Historic)?  Why
is this the proper type of RFC?  Is this type of RFC indicated in the
title page header?

[SHEPHERD] This document is a Proposed Standard document, and is
indicated in the title page as a "Standards Track" document.  This
is the proper designation for this RFC by WG consensus.




(2) The IESG approval announcement includes a Document Announcement
Write-Up. Please provide such a Document Announcement Write-Up. Recent
examples can be found in the "Action" announcements for approved
documents. The approval announcement contains the following sections:

Technical Summary

  Relevant content can frequently be found in the abstract 
  and/or introduction of the document. If not, this may be 
  an indication that there are deficiencies in the abstract 
  or introduction.


[SHEPHERD]  From the Abstract:

   Via the mechanism described in this document, subscriber applications
   may request a continuous, customized stream of updates from a YANG
   datastore.  Providing such visibility into updates enables new
   capabilities based on the remote mirroring and monitoring of
   configuration and operational state.

[SHEPHERD] From the Introduction:

   Traditional approaches to providing visibility into managed entities
   from remote have been built on polling.  With polling, data is
   periodically requested and retrieved by a client from a server to
   stay up-to-date.  However, there are issues associated with polling-
   based management:

   o  Polling incurs significant latency.  This latency prohibits many
      application types.

   o  Polling cycles may be missed, requests may be delayed or get lost,
      often when the network is under stress and the need for the data
      is the greatest.

   o  Polling requests may undergo slight fluctuations, resulting in
      intervals of different lengths.  The resulting data is difficult
      to calibrate and compare.

   o  For applications that monitor for changes, many remote polling
      cycles place unwanted and ultimately wasteful load on the network,
      devices, and applications, particularly when changes occur only
      infrequently.

   A more effective alternative to polling is for an application to
   receive automatic and continuous updates from a targeted subset of a
   datastore.  Accordingly, there is a need for a service that allows
   applications to subscribe to updates from a datastore and that
   enables the server (also referred to as publisher) to push and in
   effect stream those updates.  The requirements for such a service
   have been documented in [RFC7923].

   This document defines a corresponding solution that is built on top
   of "Custom Subscription to Event Streams"
   [I-D.draft-ietf-netconf-subscribed-notifications].  Supplementing
   that work are YANG data model augmentations, extended RPCs, and new
   datastore specific update notifications.  Transport options for
   [I-D.draft-ietf-netconf-subscribed-notifications] will work
   seamlessly with this solution.


Working Group Summary

  Was there anything in WG process that is worth noting? For 
  example, was there controversy about particular points or 
  were there decisions where the consensus was particularly 
  rough?

[SHEPHERD] Nothing in the process is worth noting.  No decisions
were particularly rough. 


Document Quality

  Are there existing implementations of the protocol? Have a 
  significant number of vendors indicated their plan to 
  implement the specification? Are there any reviewers that 
  merit special mention as having done a thorough review, 
  e.g., one that resulted in important changes or a 
  conclusion that the document had no substantive issues? If 
  there was a MIB Doctor, Media Type or other expert review, 
  what was its course (briefly)? In the case of a Media Type 
  review, on what date was the request posted?

[SHEPHERD] Apparently (not confirmed), this work has been
implemented in the OpenDayLight SDN controller.  This document 
just went through a post-LC YANG Doctor review (all issues
raised were addressed):

https://datatracker.ietf.org/doc/review-ietf-netconf-yang-push-21-yangdoctors-lc-bjorklund-2019-01-30/


Personnel

  Who is the Document Shepherd? Who is the Responsible Area
  Director?

[SHEPHERD] The Document Shepherd is Kent Watsen.  The
Responsible Area Director is Ignas Bagdonas.                


(3) Briefly describe the review of this document that was performed by
the Document Shepherd.  If this version of the document is not ready
for publication, please explain why the document is being forwarded to
the IESG.

[SHEPHERD] The shepherd has reviewed emails on the list, and tested
against `idnits`, and validated the YANG modules using both `pyang`
and `yanglint`.  The shepherd is comfortable with forwarding the 
document to the IESG at this time.


(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed?

[SHEPHERD] The Shepherd has no concerns about the depth or breadth 
of the reviews that have been performed.


(5) Do portions of the document need review from a particular or from
broader perspective, e.g., security, operational complexity, AAA, DNS,
DHCP, XML, or internationalization? If so, describe the review that
took place.

[SHEPHERD] No review from a particular or from broader perspective is 
required.


(6) Describe any specific concerns or issues that the Document Shepherd
has with this document that the Responsible Area Director and/or the
IESG should be aware of? For example, perhaps he or she is uncomfortable
with certain parts of the document, or has concerns whether there really
is a need for it. In any event, if the WG has discussed those issues and
has indicated that it still wishes to advance the document, detail those
concerns here.

[SHEPHERD] There are no specific concerns or issues that the Responsible 
Area Director and/or the IESG should be aware of.


(7) Has each author confirmed that any and all appropriate IPR
disclosures required for full conformance with the provisions of BCP 78
and BCP 79 have already been filed. If not, explain why.

[SHEPHERD] Each author has just confirmed that any and all appropriate 
IPR disclosures required for full conformance with the provisions of 
BCP 78 and BCP 79 have already been filed.  Here is the thread:
https://mailarchive.ietf.org/arch/msg/netconf/rAppo72ya1OLqLwz2cvWDJa9N-U.


(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
disclosures.

[SHEPHERD] No IPR disclosure been filed that references this document.


(9) How solid is the WG consensus behind this document? Does it 
represent the strong concurrence of a few individuals, with others
being silent, or does the WG as a whole understand and agree with it?   

[SHEPHERD] Generally solid, with many being interested in and reviewing 
this work.  


(10) Has anyone threatened an appeal or otherwise indicated extreme 
discontent? If so, please summarize the areas of conflict in separate
email messages to the Responsible Area Director. (It should be in a
separate email because this questionnaire is publicly available.) 

[SHEPHERD] No one has threatened an appeal or otherwise indicated 
extreme discontent.


(11) Identify any ID nits the Document Shepherd has found in this
document. (See https://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
thorough.

[SHEPHERD]
  - several "weird spacing" false positives warnings
  - one "unexpected reference format" ([RFC8343]'s), which RFC Editor
    should catch - one "outdated ref": SN-22 --> SN-23
  - one "Couldn't figure out when the document was first submitted"
    and related "document seems to contain a disclaimer for pre-RFC5378
    work" warnings


(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.

[SHEPHERD] The document was reviewed by the YANG doctor assigned to it.


(13) Have all references within this document been identified as
either normative or informative?

[SHEPHERD] Yes, all references within this document been identified 
as either normative or informative.


(14) Are there normative references to documents that are not ready for
advancement or are otherwise in an unclear state? If such normative
references exist, what is the plan for their completion?

[SHEPHERD] The only quazi-questionable normative references is to   
draft-ietf-netconf-subscribed-notifications, which is being submitted
to the IESG at the same time as this draft.

(15) Are there downward normative references references (see RFC 3967)?
If so, list these downward references to support the Area Director in 
the Last Call procedure. 

[SHEPHERD] There are no downward normative references.


(16) Will publication of this document change the status of any
existing RFCs? Are those RFCs listed on the title page header, listed
in the abstract, and discussed in the introduction? If the RFCs are not
listed in the Abstract and Introduction, explain why, and point to the
part of the document where the relationship of this document to the
other RFCs is discussed. If this information is not in the document,
explain why the WG considers it unnecessary.

[SHEPHERD] The publication of this document will not change the status 
of any existing RFCs.


(17) Describe the Document Shepherd's review of the IANA considerations
section, especially with regard to its consistency with the body of the
document. Confirm that all protocol extensions that the document makes
are associated with the appropriate reservations in IANA registries.
Confirm that any referenced IANA registries have been clearly
identified. Confirm that newly created IANA registries include a
detailed specification of the initial contents for the registry, that
allocations procedures for future registrations are defined, and a
reasonable name for the new registry has been suggested (see RFC 5226).

[SHEPHERD] The shepherd has reviewed the IANA Considerations section.
The document registers one URI and one YANG module. The registries 
for each of them have been identified in the document.


(18) List any new IANA registries that require Expert Review for future
allocations. Provide any public guidance that the IESG would find
useful in selecting the IANA Experts for these new registries.

[SHEPHERD] There are no new IANA registries that require Expert review
for future allocations.


(19) Describe reviews and automated checks performed by the Document
Shepherd to validate sections of the document written in a formal
language, such as XML code, BNF rules, MIB definitions, etc.

[SHEPHERD] `pyang` and `yanglint` were used to validate the YANG module 
defined in this document.  Note that Datatracker shows YANG validation 
errors, but the module validates fine on my machine (I'm using yanglint
0.16.110, whereas DataTracker is using yanglint 0.14.80).

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