Internet DRAFT - draft-tao-netmod-yang-node-tags
draft-tao-netmod-yang-node-tags
NETMOD Working Group Q. Wu
Internet-Draft Huawei
Intended status: Standards Track B. Claise
Expires: March 26, 2021 Cisco
L. Geng
Z. Du
China Mobile
M. Boucadair
Orange
September 22, 2020
Self Describing Data Object Tags
draft-tao-netmod-yang-node-tags-06
Abstract
This document defines a method to tag data objects associated with
operation and management data in YANG Modules. This YANG data object
tagging method can be used to classify data objects from different
YANG modules and identify characteristics data. It also can provide
input, instruction, indication to selection filter and filter queries
of operational state on a server during a "pub/sub" service for YANG
datastore updates. When the state of all subscriptions of a
particular Subscriber to be fetched is huge, the amount of data to be
streamed out to the destination can be greatly reduced and only
targeted to the characteristics data. These data object tags may be
registered as well as assigned during the module definition; assigned
by implementations; or dynamically defined and set by users.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 26, 2021.
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Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Self Describing Data Object Tags Use Case . . . . . . . . 4
1.1.1. Massive Data Object Collection . . . . . . . . . . . 4
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6
2. Data Object Tag Values . . . . . . . . . . . . . . . . . . . 6
2.1. IETF Tags Prefix . . . . . . . . . . . . . . . . . . . . 7
2.2. Vendor Tags Prefix . . . . . . . . . . . . . . . . . . . 7
2.3. User Tags Prefix . . . . . . . . . . . . . . . . . . . . 7
2.4. Reserved Tags Prefix . . . . . . . . . . . . . . . . . . 7
3. Data Object Tag Management . . . . . . . . . . . . . . . . . 7
3.1. Module Design Tagging . . . . . . . . . . . . . . . . . . 8
3.2. Implementation Tagging . . . . . . . . . . . . . . . . . 8
3.3. User Tagging . . . . . . . . . . . . . . . . . . . . . . 9
4. Data Object Tags Module Structure . . . . . . . . . . . . . . 9
4.1. Data Object Tags Module Tree . . . . . . . . . . . . . . 9
5. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 9
6. Guidelines to Model Writers . . . . . . . . . . . . . . . . . 12
6.1. Define Standard Tags . . . . . . . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
7.1. YANG Data Object Tag Prefixes Registry . . . . . . . . . 13
7.2. IETF YANG Data Object Tags Registry . . . . . . . . . . . 14
7.3. Updates to the IETF XML Registry . . . . . . . . . . . . 16
7.4. Updates to the YANG Module Names Registry . . . . . . . . 16
8. Security Considerations . . . . . . . . . . . . . . . . . . . 16
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
10.1. Normative References . . . . . . . . . . . . . . . . . . 17
10.2. Informative References . . . . . . . . . . . . . . . . . 17
Appendix A. NETCONF Example . . . . . . . . . . . . . . . . . . 18
Appendix B. Non-NMDA State Module . . . . . . . . . . . . . . . 19
Appendix C. Targeted data object collection example . . . . . . 22
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Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25
1. Introduction
As described in [I.D-ietf-netmod-module-tags], the use of tags for
classification and organization is fairly ubiquitous not only within
IETF protocols, but in the internet itself (e.g., "#hashtags"). A
module tag defined in [I.D-ietf-netmod-module-tags] is a string
associated only with a module name at module level.
At the time of writing this document (2020), there are many data
models that have been specified or are being specified by various
different SDOs and Open Souce community. They cover many of the
networking protocols and techniques. However data objects defined by
these technology specific data models might represent a portion of
fault, configuration, accounting, performance, security management
categories information at different locations in various different
ways, lack consistent classification criteria and representation for
a specific service, feature or data source.
This document defines self-describing data object tags and associates
them with data objects within YANG module, which
o Provide dictionary meaning for specific targeted data objects;
o Indicate relationship between data objects within the same YANG
module or from different YANG modules;
o Identify key performance metric data objects and the absolute
XPath expression identifying the element path to the node;
The self describing data object tags can be used by the client to
classify data objects from different YANG modules and identify
characteristics data. In addition, it can provide input,
instruction, indication to selection filter and filter queries of
configuration or operational state on a server based on these data
object tags, .e.g., return specific object type of operational state
related to system-management. NETCONF clients can discover data
objects with self describing data object tags supported by a NETCONF
server via <get-schema> operation. The self describing data object
tag capability can also be advertised via Capability Notification
Model [I-D.netconf-notification-capabilities] by the NETCONF server
or some place where offline document are kept. These data object
tags may be registered as well as assigned during the module
definition; assigned by implementations; or dynamically defined and
set by users.
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This document defines a YANG module [RFC7950] which augments module
tag model and provides a list of data object entries to allow for
adding or removing of self describing tags as well as viewing the set
of self describing tags associated with specific data objects within
YANG modules.
This document defines an extension statement to be used to indicate
self describing tags that SHOULD be added by the module
implementation automatically (i.e., outside of configuration).
This document also defines an IANA registry for tag prefixes as well
as a set of globally assigned tags.
Section 6 provides guidelines for authors of YANG data models.
The YANG data model in this document conforms to the Network
Management Datastore Architecture defined in [RFC8342].
1.1. Self Describing Data Object Tags Use Case
1.1.1. Massive Data Object Collection
Among data object tags, the opm (object, property subobject, metric
subobject) tags can be used to tackle massive data objects collection
and only capture YANG data objects associated with performance
metrics data modelled with YANG (See Figure 1).
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/-----\ /-----\
/Property\ /Property\
|Subobject+------+ +-------+Subobject|
\ A / | | \ B /
+- ---+ +--V-------------V-+ ----- +---------------+
| YANG Data Node | | YANG Data Node|
| /Data Object 1 |-------------------| /Data Object 3|
/---\ +--^-------------^-+ /---\ +-------^-------+
Metric\ | | | Metric |
|Subobject------+ | +--------|Subobject /--+-\
\ C / | \ D / Property
\-+-/ | \-+-/ |Subobject
| +------+ | \ G /
| |Metric+----+ \----/
| |Group |----+
/----\ | +------+ |
Property | |
|Subobject | |
\ E / | |
\--+-/ | /----\
| +-------------------+ /Metric\
| | YANG Data Node <-------|Subobject
+---> /Data Object 2 | \ F /
+-------------------+ \----/
Figure 1: The Relation between Object, Property and Metric
In Figure 1, object can contain other objects called subobjects.
Property and metric objects are both subobjects belonging to specific
object. Both object and subobjects can be modeled as YANG data nodes
[RFC7950]. Object can be one of container, leaf-list and list.
Property subobject is a leaf node. Metric subobject can be one of
container, leaf-list, list, leaf node. Object contains zero or many
property subobjects, zero or many metric subobjects.
The use of opm tags would be to help filter discrete categories of
YANG data objects scattered across the same or different YANG modules
supported by a device and capture all network performance data or all
property data in the single view of the truth (see Figure 2). In
Figure 2, tunnel-svc data object is a container node in the tunnel-pm
module and can be seen as the root object for property subobjects
(e.g., tunnel-svc/create-time) and metric subobjects (e.g.,tunnel-
svc/avg-latency). Name, create-time, modified-time are property
subobjects under tunnel-svc container. Avg-latency,packet loss are
metric subobjects under tunnel-svc container node. In addition, not
all metric subobjects need to be tagged, e.g., only specific category
(e.g., loss related) metric subobjects need to be tagged with metric-
group tag which can further reduce amount data to be fetched.
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+------------------------+--------------------------------------------+
| Data | Object Property Metric Module |
| Object | Tag Subobject Subobject Name |
| | Tag Tag |
+------------------------+--------------------------------------------+
| | ietf: |
|tunnel-svc | object tunnel-pm|
| | ietf: |
|tunnel-svc/name | property tunnel-pm|
| | ietf: |
|tunnel-svc/create-time | property tunnel-pm|
| | ietf: |
|tunnel-svc/modified-time| property tunnel-pm|
| | |
|tunnel-svc/avg-latency | ietf: tunnel-pm|
| | metric |
|tunnel-svc/packet-loss | ietf: tunnel-pm|
| | metric |
|tunnel-svc/min-latency | ietf: tunnel-pm|
| | metric |
|tunnel-svc/ max-latency | ietf: tunnel-pm|
| | metric |
+------------------------+--------------------------------------------+
Figure 2: Example of OPM Tags Used in the YANG Module
If data objects in these YANG modules are suitably tagged and learnt
by the client from a live server, the client can retrieve paths to
all targeted data objects and then use an XPath query defined
[RFC8639] [RFC8641] to list all tagged data objects which reflect
network characteristics
1.2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Data Object Tag Values
All data object tags SHOULD begin with a prefix indicating who owns
their definition. An IANA registry (Section 7.1) is used to support
registering data object tag prefixes. Currently 3 prefixes are
defined.
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No further structure is imposed by this document on the value
following the registered prefix, and the value can contain any YANG
type 'string' characters except carriage-returns, newlines and tabs.
Therefore, designers, implementers, and users are free to add or not
add any structure they may require to their own tag values.
2.1. IETF Tags Prefix
An IETF tag is a data object tag that has the prefix "ietf:". All
IETF data object tags are registered with IANA in a registry defined
later in this document (Section 7.2).
2.2. Vendor Tags Prefix
A vendor tag is a tag that has the prefix "vendor:". These tags are
defined by the vendor that implements the module, and are not
registered; however, it is RECOMMENDED that the vendor include extra
identification in the tag to avoid collisions such as using the
enterprise or organization name following the "vendor:" prefix (e.g.,
vendor:vendor-defined-classifier).
2.3. User Tags Prefix
A user tag is any tag that has the prefix "user:". These tags are
defined by the user/administrator and are not meant to be registered.
Users are not required to use the "user:" prefix; however, doing so
is RECOMMENDED as it helps avoid prefix collisions.
2.4. Reserved Tags Prefix
Any tag not starting with the prefix "ietf:", "vendor:" or "user:" is
reserved for future use. These tag values are not invalid, but
simply reserved in the context of specifications (e.g., RFCs).
3. Data Object Tag Management
Tags can become associated with a data object within YANG module in a
number of ways. Tags may be defined and associated at the module
design time, at implementation time without the need of live server,
or via user administrative control . As the main consumer of data
object tags are users, users may also remove any tag from a live
server, no matter how the tag became associated with a data object
within a YANG module.
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3.1. Module Design Tagging
A data object definition MAY indicate a set of data object tags to be
added by the module implementer. These design time tags are
indicated using a set of extension statements which include:
opm-tag extension statement: Classify management and operation data
into object, property subobject and metric subobject three
categories. Object can contain other objects called subobjects.
Property and metric objects are both subobjects belonging to
specific object. Both object and subobjects can be modeled as
data nodes [RFC7950]. Object can be one of container, leaf-list
and list. Property subobject is a leaf node. Metric subobject
can be one of container, leaf-list, list, leaf. Object contains
zero or many property subobjects, zero or many metric subobjects.
See opm-tag example in Figure 2 and Figure 3.
metric-group extension statement: Provide meric subobjects
classification (e.g., loss, jitter, delay) within the YANG module.
multi-source-tag extension statement: Identify multi-source
aggregation type (e.g., aggregated, non-aggregated) related to
metric subobject. 'aggregated' multi-source aggregation type
allows a large number of measurements on metric subobjects from
different sources of the same type (e.g.,line card, each
subinterface of aggregated Ethernet interface) being combined into
aggregated statistics and report as one metric subobject. 'non-
aggregated' multi-source aggregation type allows measurement from
each source of the same type (e.g.,line card, each subinterface of
aggregated Ethernet interface) be reported separately.
Among these extension statements, the metric-group, multi-source-tag
extension statements are context information related and can be used
to correlate data object from the different modules.
If the data node is defined in an IETF standards track document, the
data object tags MUST be IETF Tags (2.1). Thus, new data object can
drive the addition of new IETF tags to the IANA registry defined in
Section 7, and the IANA registry can serve as a check against
duplication.
3.2. Implementation Tagging
An implementation MAY include additional tags associated with data
object within a YANG module. These tags SHOULD be IETF Tags (i.e.,
registered) or vendor specific tags.
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3.3. User Tagging
Data object tags of any kind, with or without a prefix, can be
assigned and removed by the user from a live server using normal
configuration mechanisms. In order to remove a data object tag from
the operational datastore, the user adds a matching "masked-tag"
entry for a given data object within the ietf-data-object-tags
Module.
4. Data Object Tags Module Structure
4.1. Data Object Tags Module Tree
The tree associated with the "ietf-data-object-tags" module follows.
The meaning of the symbols can be found in [RFC8340].
module: ietf-data-object-tags
augment /tags:module-tags/tags:module:
+--rw data-object-tags
+--rw data-object* [object-name]
+--rw object-name nacm:node-instance-identifier
+--rw tag* tags:tag
+--rw masked-tag* tags:tag
5. YANG Module
<CODE BEGINS> file "ietf-data-object-tags@2019-05-03.yang"
module ietf-data-object-tags {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-data-object-tags";
prefix ntags;
import ietf-netconf-acm {
prefix nacm;
}
import ietf-module-tags {
prefix tags;
}
organization
"IETF NetMod Working Group (NetMod)";
contact
"WG Web: <https://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
Editor: Qin Wu <mailto:bill.wu@huawei.com>
Editor: Benoit Claise <mailto:bclaise@cisco.com>
Editor: Liang Geng <mailto:gengliang@chinamobile.com>
Editor: Zongpeng Du <mailto:duzongpeng@chinamobile.com>
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Editor: Mohamed Boucadair <mailto:mohamed.boucadair@orange.com>";
description
"This module describes a mechanism associating self-describing
tags with YANG data object within YANG modules. Tags may be IANA
assigned or privately defined.
Copyright (c) 2020 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Simplified BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://tools.ietf.org/html/rfcXXXX); see the RFC itself for
full legal notices.";
revision 2019-05-03 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Data Object Tags";
}
extension opm-tag {
argument tag;
description
"The argument 'tag' is of type 'tag'. This extension statement
is used by module authors to indicate the opm tags that SHOULD be
added automatically by the system. Opm Tag is used to classify
operation and management data into object, property subobject, and metric
subobject three categories. Object can contain other objects called subobjects.
Property and metric objects are both subobjects belonging to specific object.
Both object and subobjects can be modeled as data nodes. Object can be one of
container, leaf-list and list. Property subobject is a leaf node. Metric subobject
can be one of container, leaf-list, list, leaf. Object contains zero or many
property subobjects, zero or many metric subobjects. As such the origin of the
value for the pre-defined tags should be set to 'system'[RFC8342].";
}
extension metric-group {
argument tag;
description
"The argument 'tag' is of type 'tag'.The metric-group can be
used to provide metric subobject classification
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(e.g., loss, jitter, packet loss) within the YANG module.";
}
extension multi-source-tag {
argument tag;
description
"The argument 'tag' is of type 'tag'.The multi-source-tag can be
used to identify multi-source aggregation type (e.g., aggregated,
non-aggregated) related to metric subobject.
'aggregated' multi-source aggregation type allows a large number of
measurements on metric subobjects from different sources of the same
type (e.g.,line card, each subinterface of aggregated Ethernet interface)
being combined into aggregated statistics and report as one metric subobject
value. 'non-aggregated' multi-source aggregation type allows measurement from
each source of the same type (e.g.,line card, each subinterface of aggregated
Ethernet interface) be reported separately.";
}
augment "/tags:module-tags/tags:module" {
description
"Augment the Module Tags module with data object tag attributes";
container data-object-tags {
description
"Contains the list of data objects and their associated data object tags";
list data-object {
key "object-name";
description
"A list of data objects and their associated data object tags";
leaf object-name {
type nacm:node-instance-identifier;
mandatory true;
description
"The YANG data object name.";
}
leaf-list tag {
type tags:tag;
description
"Tags associated with the data object within the YANG module. See
the IANA 'YANG Data Object Tag Prefixes' registry for reserved
prefixes and the IANA'IETF YANG Data Object Tags' registry for
IETF tags.
The 'operational' state [RFC8342] view of this list is
constructed using the following steps:
1) System tags (i.e., tags of 'system' origin) are added.
2) User configured tags (i.e., tags of 'intended' origin)
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are added.
3) Any tag that is equal to a masked-tag is removed.";
}
leaf-list masked-tag {
type tags:tag;
description
"The list of tags that should not be associated with the data
object within the YANG module. The user can remove (mask) tags from the
operational state datastore [RFC8342] by adding them to
this list. It is not an error to add tags to this list
that are not associated with the data object within YANG module,
but they have no operational effect.";
}
}
}
}
}
<CODE ENDS>
6. Guidelines to Model Writers
This section updates [RFC8407].
6.1. Define Standard Tags
A module MAY indicate, using data object tag extension statements, a
set of data object tags that are to be automatically associated with
data object within the module (i.e., not added through
configuration).
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module example-module-A {
//...
import ietf-data-node-tags { prefix ntags; }
container top {
ntags:opm-tag "ietf:object";
list X {
leaf foo {
ntags:opm-tag "ietf:property";
}
}
container Y {
leaf bar {
ntags:opm-tag "ietf:metric";
}
}
}
// ...
}
Figure 3: Data object tag example
The module writer can use existing standard data object tags, or use
new data object tags defined in the data object definition, as
appropriate. For IETF standardized modules, new data object tags
MUST be assigned in the IANA registry defined below, see
Section Section 7.2.
7. IANA Considerations
7.1. YANG Data Object Tag Prefixes Registry
IANA is asked to create a new registry "YANG Data Object Tag
Prefixes" grouped under a new "Protocol" category named "YANG Data
Object Tag Prefixes".
This registry allocates tag prefixes. All YANG Data Object Tags
SHOULD begin with one of the prefixes in this registry.
Prefix entries in this registry should be short strings consisting of
lowercase ASCII alpha-numeric characters and a final ":" character.
The allocation policy for this registry is Specification Required
[RFC8126]. The Reference and Assignee values should be sufficient to
identify and contact the organization that has been allocated the
prefix.
The initial values for this registry are as follows.
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+----------+----------------------------------+-----------+----------+
| Prefix | Description | Reference | Assignee |
+----------+----------------------------------+-----------+----------+
| ietf: | IETF Tags allocated in the IANA | [This | IETF |
| | IETF YANG Data Object Tags registry document]| |
| | | | |
|vendor: | Non-registered tags allocated by | [This | IETF |
| | the module implementer. | document] | |
| | | | |
| user: | Non-registered tags allocated by | [This | IETF |
| | and for the user. | document] | |
+----------+----------------------------------+-----------+----------+
Other standards organizations (SDOs) wishing to allocate their own
set of tags should allocate a prefix from this registry.
7.2. IETF YANG Data Object Tags Registry
IANA is asked to create 3 new registries "IETF OPM Tags","IETF Metric
Group Tags","IETF Multiple Source Tags" grouped under a new
"Protocol" category. These 3 registries should be included below
"YANG Data Object Tag Prefixes" when listed on the same page.
3 registries allocate tags that have the registered prefix "ietf:".
New values should be well considered and not achievable through a
combination of already existing IETF tags.
The allocation policy for these three registries is IETF Review
[RFC8126].
The initial values for these three registries are as follows.
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+----------------------------+--------------------------+-----------+
| OPM Tag | Description | Reference |
+----------------------------+--------------------------+-----------+
| | | |
| ietf:object |Represent specific object | [This |
| |type(e.g., interfaces). | document] |
| | | |
| ietf:property |Represent a property | [This |
| |subobject (e.g.,ifindex) | document] |
| |assoiciated with specific | |
| |object (e.g.,interfaces). | |
| | | |
| ietf:metric |Represent metric subobject| [This |
| |(e.g., ifstatistics) | document] |
| |associated with specific | |
| | object(e.g.,interfaces) | |
+----------------------------+--------------------------+-----------+
+----------------------------+--------------------------+-----------+
| Metric Group Tag | Description | Reference |
+----------------------------+--------------------------+-----------+
| ietf:delay |Represent the metric group| [This |
| |which metric subobjects | document] |
| |belong to (i.e., delay) | |
| | | |
| ietf:jitter |Represent the metric group| [This |
| |which metric subobjects |document] |
| |belong to (i.e., jitter) | |
| | | |
| ietf:loss |Represent the metric group| [This |
| |which metric subobjects | document] |
| |belong to (i.e.,loss) | |
+----------------------------+--------------------------+-----------+
+----------------------------+--------------------------+-----------+
| Multiple Source Tag | Description | Reference |
+----------------------------+--------------------------+-----------+
|ietf:non-agg |Relate to multiple source | [This |
| |aggregation type(i.e., | document] |
| |aggregated statistics) | |
| | | |
|ietf:agg |Relate to multiple source | [This |
| |aggregation type(i.e., non| document] |
| |aggregated statistics) | |
+----------------------------+--------------------------+-----------+
Each YANG data object can have one opm tag, zero or one metric-group
tag, zero or one multi-source tag.
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7.3. Updates to the IETF XML Registry
This document registers a URI in the "IETF XML Registry" [RFC3688].
Following the format in [RFC3688], the following registration has
been made:
URI:
urn:ietf:params:xml:ns:yang:ietf-data-object-tags
Registrant Contact:
The IESG.
XML:
N/A; the requested URI is an XML namespace.
7.4. Updates to the YANG Module Names Registry
This document registers one YANG module in the "YANG Module Names"
registry [RFC6020]. Following the format in [RFC6020], the following
registration has been made:
name:
ietf-data-object-tags
namespace:
urn:ietf:params:xml:ns:yang:ietf-data-object-tags
prefix:
ntags
reference:
RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove
this note.)
8. Security Considerations
The YANG module defined in this memo is designed to be accessed via
the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the
secure transport layer and the mandatory-to-implement secure
transport is SSH [RFC6242].
This document adds the ability to associate data object tag meta-data
with data object within the YANG modules. This document does not
define any actions based on these associations, and none are yet
defined, and therefore it does not by itself introduce any new
security considerations.
Users of the data object tag meta-data may define various actions to
be taken based on the data object tag meta-data. These actions and
their definitions are outside the scope of this document. Users will
need to consider the security implications of any actions they choose
to define.
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9. Acknowledgements
The authors would like to thank Ran Tao for his major contributions
to the initial modeling and use cases. The authors would also like
to acknowledge the comments and suggestions received from Juergen
Schoenwaelder, Andy Bierman, Lou Berger,Jaehoon Paul Jeong, Wei Wang,
Yuan Zhang, Ander Liu, Peng Liu, YingZhen Qu, Boyuan Yan.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of
Documents Containing YANG Data Models", BCP 216, RFC 8407,
DOI 10.17487/RFC8407, October 2018,
<https://www.rfc-editor.org/info/rfc8407>.
10.2. Informative References
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
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[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
E., and A. Tripathy, "Subscription to YANG Notifications",
RFC 8639, DOI 10.17487/RFC8639, September 2019,
<https://www.rfc-editor.org/info/rfc8639>.
[RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications
for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641,
September 2019, <https://www.rfc-editor.org/info/rfc8641>.
Appendix A. NETCONF Example
The following is a fictional NETCONF example result from a query of
the data object tags list. For the sake of brevity only a few module
and associated data object results are imagined.
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<ns0:data xmlns:ns0="urn:ietf:params:xml:ns:netconf:base:1.0">
<t:module-tags xmlns:t="urn:ietf:params:xml:ns:yang:ietf-module-tags">
<t:module>
<t:name>ietf-interfaces</t:name>
<s:data-object-tags xmlns:s="urn:ietf:params:xml:ns:yang:ietf-data-object-tags">
<s:data-object>
<s:object-name>/if:interfaces/if:interface</s:object-name>
<s:tag>ietf:object</s:tag>
</s:data-object>
<s:data-object>
<s:object-name>/if:interfaces/if:interface/if:last-change</s:object-name>
<s:tag>ietf:property</s:tag>
</s:data-object>
<s:data-object>
<s:object-name>
/if:interfaces/if:interface/if:statistics/if:in-errors
</s:object-name>
<s:tag>ietf:metric</s:tag>
</s:data-object>
</s:data-object-tags>
</t:module>
<t:module>
<t:name>ietf-ip</t:name>
<s:data-object-tags xmlns:s="urn:ietf:params:xml:ns:yang:ietf-data-object-tags">
<s:data-object>
<s:object-name>/if:interfaces/if:interface/ip:ipv4</s:object-name>
<s:tag>ietf:object</s:tag>
</s:data-object>
<s:data-object>
<s:object-name>/if:interfaces/if:interface/ip:ipv4/ip:enable</s:object-name>
<s:tag>ietf:property</s:tag>
</s:data-object>
<s:data-object>
<s:object-name>/if:interfaces/if:interface/ip:ipv4/ip:mtu</s:object-name>
<s:tag>ietf:metric</s:tag>
</s:data-object>
</s:data-object-tags>
</t:module>
</t:module-tags>
</ns0:data>
Appendix B. Non-NMDA State Module
As per [RFC8407] the following is a non-NMDA module to support
viewing the operational state for non-NMDA compliant servers.
<CODE BEGINS> file "ietf-data-object-tags-state@2019-05-03.yang"
module ietf-data-object-tags-state {
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yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-data-object-tags-state";
prefix ntags-s;
import ietf-netconf-acm {
prefix nacm;
}
import ietf-module-tags {
prefix tags;
}
organization
"IETF NetMod Working Group (NetMod)";
contact
"WG Web: <https://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
Editor: Qin Wu <mailto:bill.wu@huawei.com>
Editor: Benoit Claise <mailto:bclaise@cisco.com>
Editor: Liang Geng <mailto:gengliang@chinamobile.com>
Editor: Zongpeng Du <mailto:duzongpeng@chinamobile.com>";
description
"This module describes a mechanism associating self-describing
tags with YANG data object within YANG modules. Tags may be IANA
assigned or privately defined.
Copyright (c) 2020 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Simplified BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://tools.ietf.org/html/rfcXXXX); see the RFC itself for
full legal notices.";
revision 2019-05-03 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Data Object Tags";
}
extension opm-tag {
argument tag;
description
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"The argument 'tag' is of type 'tag'. This extension statement
is used by module authors to indicate the opm tags that SHOULD be
added automatically by the system. Opm Tag is used to classify
operation and management data into object, property subobject, and metric
subobject three categories. Object can contain other objects called subobjects.
Property and metric objects are both subobjects belonging to specific object.
Both object and subobjects can be modeled as data nodes. Object can be one of
container, leaf-list and list. Property subobject is a leaf node. Metric subobject
can be one of container, leaf-list, list, leaf. Object contains zero or many
property subobjects, zero or many metric subobjects. As such the origin of the value
for the pre-defined tags should be set to 'system'[RFC8342].";
}
extension metric-group {
argument tag;
description
"The argument 'tag' is of type 'tag'.The metric-group can be
used to provide metric subobject classification
(e.g., loss, jitter, packet loss)within the YANG module.";
}
extension multi-source-tag {
argument tag;
description
"The argument 'tag' is of type 'tag'.The multi-source-tag can be
used to identify multi-source aggregation type (e.g., aggregated,
non-aggregated) related to metric subobject.
'aggregated' multi-source aggregation type allows a large number of
measurements on metric subobjects from different sources of the same
type (e.g.,line card, each subinterface of aggregated Ethernet interface)
being combined into aggregated statistics and report as one metric subobject
value. 'non-aggregated' multi-source aggregation type allows measurement from
each source of the same type (e.g.,line card, each subinterface of aggregated
Ethernet interface) be reported separately.";
}
augment "/tags:module-tags/tags:module" {
description
"Augment the Module Tags module with data object tag attributes";
container data-object-tags {
config false;
status deprecated;
description
"Contains the list of data objects and their associated self describing tags";
list data-object {
key "object-name";
status deprecated;
description
"A list of data objects and their associated self describing tags";
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leaf object-name {
type nacm:node-instance-identifier;
mandatory true;
status deprecated;
description
"The YANG data object name.";
}
leaf-list tag {
type tags:tag;
status deprecated;
description
"Tags associated with the data object within the YANG module. See
the IANA 'YANG Data Object Tag Prefixes' registry for reserved
prefixes and the IANA'IETF YANG Data Object Tags' registry for
IETF tags.
The 'operational' state [RFC8342] view of this list is
constructed using the following steps:
1) System tags (i.e., tags of 'system' origin) are added.
2) User configured tags (i.e., tags of 'intended' origin)
are added.
3) Any tag that is equal to a masked-tag is removed.";
}
leaf-list masked-tag {
type tags:tag;
status deprecated;
description
"The list of tags that should not be associated with the data
object within the YANG module. The user can remove (mask) tags from the
operational state datastore [RFC8342] by adding them to
this list. It is not an error to add tags to this list
that are not associated with the data object within YANG module,
but they have no operational effect.";
}
}
}
}
}
<CODE ENDS>
Appendix C. Targeted data object collection example
The following subsections provides targeted data object collection
example which helps reduce amount of data to be fetched. The
subscription "id" values of 22 used below is just an example. In
production, the actual values of "id" might not be small integers.
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+-----------+ +-----------+
| Subscriber| | Publisher |
+------+----+ +-----+-----+
| |
| |
|Telemery data Tagging Advertisement
| (data object name, opm-tag = metric)
|<---------------------------------|
| |
| establish-subscription |
|--------------------------------->|
| |
| |
| RPC Reply: OK, id = 22 |
|<---------------------------------|
| |
| |
| Notification Message (for 22) |
| <--------------------------------|
| |
| |
The publisher advertises telemetry data object capability to the
subscriber to instruct the receiver to subscribe tagged data object
(e.g., performance metric data object) using standard subscribed
notification mechanism [RFC8639].
The following XML example [W3C.REC-xml-20081126] illustrates the
advertisment of the list of available target objects using YANG
instance file format [I-D.ietf-netmod-yang-instance-file-format]:
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<?xml version="1.0" encoding="UTF-8"?>
<instance-data-set xmlns=\
"urn:ietf:params:xml:ns:yang:ietf-yang-instance-data">
<name>acme-router-notification-capabilities</name>
<content-schema>
<module>ietf-system-capabilities@2020-03-23</module>
<module>ietf-notification-capabilities@2020-03-23</module>
<module>ietf-data-export-capabilities@2020-03-23</module>
</content-schema>
<!-- revision date, contact, etc. -->
<description>Defines the notification capabilities of an acme-router.
The router only has running, and operational datastores.
Every change can be reported on-change from running, but
only config=true nodes and some config=false data from operational.
Statistics are not reported based on timer based trigger and counter
threshold based trigger.
</description>
<content-data>
<system-capabilities \
xmlns="urn:ietf:params:xml:ns:yang:ietf-system-capabilities" \
xmlns:inc=\
"urn:ietf:params:xml:ns:yang:ietf-notification-capabilities" \
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
<datastore-capabilities>
<datastore>ds:operational</datastore>
<per-node-capabilities>
<node-selector>\
/if:interfaces/if:interface/if:statistics/if:in-errors\
</node-selector>
<sec:self-describing-capabilities>
<sec:opm-tag>metric</sec:opm-tag>
<sec:metric-group>loss</sec:metric-group>
</sec:self-describing-capabilities>
</per-node-capabilities>
</datastore-capabilities>
</system-capabilities>
</content-data>
</instance-data-set>
With telemetry data tagging information carried in the Telemetry data
Tagging Advertisement, the subscriber identifies targeted data object
and associated data path to the datastore node and sends a standard
establish-subscription RPC [RFC8639] to subscribe tagged data objects
that are interests to the client application from the publisher.
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<netconf:rpc message-id="101"
xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">
<establish-subscription
xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"
xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">
<yp:datastore
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
ds:operational
</yp:datastore>
<yp:datastore-xpath-filter
xmlns:ex="https://example.com/sample-data/1.0">
/if:interfaces/if:interface/if:statistics/if:in-errors
</yp:datastore-xpath-filter>
<yp:periodic>
<yp:period>500</yp:period>
</yp:periodic>
</establish-subscription>
</netconf:rpc>
The publisher returns specific object type of operational state
(e.g., in-errors statistics data) subscribed by the client.
Authors' Addresses
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
Benoit Claise
Cisco
De Kleetlaan 6a b1
Diegem 1831
Belgium
Email: bclaise@cisco.com
Liang Geng
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing 10053
Email: gengliang@chinamobile.com
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Zongpeng Du
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing 10053
Email: duzongpeng@chinamobile.com
Mohamed Boucadair
Orange
Rennes 35000
France
Email: mohamed.boucadair@orange.com
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