Subject: [netmod] Review of draft-wwx-netmod-event-yang-09

From: "Jonathan Hansford" <[email-masked]>
Date: Fri, 31 Jul 2020 11:29:00 +0000

Hi,

Most of my comments are editorial and to date only address up to the end 
of Section 2:

Page 1

    Could the Abstract be simplified to:
       This document defines a YANG data model for Event Condition Action
       (ECA) policy management.  The ECA policy YANG module provides the
       ability to delegate some network management functions to the 
server
       which can take simple and instant action when a trigger condition 
on
       the system state is met.

Page 3

    1. Introduction

    1st bullet should end in a semi-colon, not a period

    2nd bullet:
       s/large amount/large amounts

    3rd bullet:
       s/can not/cannot

       s/disconnected from/not connected to

    4th bullet:
       s/devices needs/devices need

       s/hundeds/hundreds

       I think a comma after "notifications" would make it easier to 
parse the sentence which should end in a period, not a semi-colon

    Either
       s/network management function/the network management function
    Or
       s/network management function/network management functions

    s/server monitor/server to monitor

    Is it a service or the server that is providing continuous 
performance monitoring?

    s/monitoring and detect defects and failures and/monitoring, detect 
defects and failures, and

    s/a ECA Policy/an ECA Policy

    The second sentence of the penultimate paragraph on page 3 is too 
long, confusing and unstructured. It needs re-writing.

Page 4

    2.1. Terminology

    Might it be worth including definitions from RFC3198 "Terminology for 
Policy-Based Management" as well, either to explain how this Internet 
Draft aligns or where it deviates? For example:

    o  Policy Decision Point (PDP)

    o  Policy Enforcement Point (PEP)

    o  provisioned policy

    It seems to me this Internet Draft provides support for provisioned 
policies where the server is both the PDP and the PEP.

    Neither "Implicit policy variable" nor "Explicit policy variable" are 
defined in RFC3460, though it does introduce (but not formally define) 
the following terms. Be good to properly align with the terms in the 
RFC:

    o  "Implicit PolicyVariable", "Implicitly bound policy variable" and 
"Implicitly defined policy variable"

    o  "Explicitly bound policy variable" and "Explicitly defined policy 
variable"

    Event: The definition of "Event" is a direct lift from RFC5277, so 
shouldn't it just be included it in the list of predefined terms? 
However, it appears the term that is actually used in the Internet Draft 
is "Notification" (in the definitions of Server Event and Datastore 
Event) and, since "Event" is such an overloaded term, it may be better 
to define "Notification".

    Event Stream is used in this Internet Draft, where "Stream" is 
defined in RFC5277.

    Condition: s/cause/causes

    Action: s/Updates or invocations/Update or invocation

    ECA Event:

       Is something missing in this definition, should there be a period 
after "processing", or should "Derived" not have a capital "D"?

       s/extensible list/an extensible list

    Datastore Event: s/for a/for which a

    Self Monitoring: I find it confusing that "Self Monitoring" 
encompasses both monitor and control.

    Self Healing:

       s/discovery, and correction/discovery and correction

       s/actions/Actions

       s/system/the system

    Policy Variable (PV): It is rather confusing that this Internet Draft 
both uses the definition of "policy variable" from RFC3460 and has its 
own definition. Should we just rely on capitalisation to determine which 
is meant?

Jonathan