Self Describing Data Object Tags
draft-ietf-netmod-node-tags-04
The information below is for an old version of the document.
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|---|---|---|---|
| Authors | Qin Wu , Benoît Claise , Peng Liu , Zongpeng Du , Mohamed Boucadair | ||
| Last updated | 2021-12-27 (Latest revision 2021-11-11) | ||
| Replaces | draft-tao-netmod-yang-node-tags | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
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| Reviews |
YANGDOCTORS Last Call review
by Mahesh Jethanandani
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draft-ietf-netmod-node-tags-04
NETMOD Working Group Q. Wu
Internet-Draft B. Claise
Updates: 8407 (if approved) Huawei
Intended status: Standards Track P. Liu
Expires: 15 May 2022 Z. Du
China Mobile
M. Boucadair
Orange
11 November 2021
Self Describing Data Object Tags
draft-ietf-netmod-node-tags-04
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 their characteristics data. It can also
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 subscriptions of a
particular subscriber to be fetched is very large, the amount of data
to be streamed out to the destination can be 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 15 May 2022.
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Copyright Notice
Copyright (c) 2021 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
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Requirements Notation . . . . . . . . . . . . . . . . . . 4
2.2. Glossary . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Self Describing Data Object Tags: Massive Data Object
Collection Use Case . . . . . . . . . . . . . . . . . . . 5
4. Data Object Tag Values . . . . . . . . . . . . . . . . . . . 7
4.1. IETF Tags Prefix . . . . . . . . . . . . . . . . . . . . 7
4.2. Vendor Tags Prefix . . . . . . . . . . . . . . . . . . . 7
4.3. User Tags Prefix . . . . . . . . . . . . . . . . . . . . 7
4.4. Reserved Tags Prefix . . . . . . . . . . . . . . . . . . 8
5. Data Object Tag Management . . . . . . . . . . . . . . . . . 8
5.1. Module Design Tagging . . . . . . . . . . . . . . . . . . 8
5.2. Implementation Tagging . . . . . . . . . . . . . . . . . 9
5.3. User Tagging . . . . . . . . . . . . . . . . . . . . . . 9
6. Data Object Tags Module Structure . . . . . . . . . . . . . . 9
6.1. Data Object Tags Module Tree . . . . . . . . . . . . . . 9
7. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Guidelines to Model Writers . . . . . . . . . . . . . . . . . 13
8.1. Define Standard Tags . . . . . . . . . . . . . . . . . . 13
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
9.1. YANG Data Object Tag Prefixes Registry . . . . . . . . . 14
9.2. IETF YANG Data Object Tags Registry . . . . . . . . . . . 14
9.3. Updates to the IETF XML Registry . . . . . . . . . . . . 16
9.4. Updates to the YANG Module Names Registry . . . . . . . . 17
10. Security Considerations . . . . . . . . . . . . . . . . . . . 17
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 18
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 18
13.1. Normative References . . . . . . . . . . . . . . . . . . 18
13.2. Informative References . . . . . . . . . . . . . . . . . 19
Appendix A. NETCONF Example . . . . . . . . . . . . . . . . . . 19
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Appendix B. Non-NMDA State Module . . . . . . . . . . . . . . . 20
Appendix C. Targeted data object collection example . . . . . . 24
Appendix D. Changes between Revisions . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27
1. Introduction
As described in [RFC8819], the use of tags for classification and
organization is fairly ubiquitous not only within IETF protocols, but
in the Internet itself (e.g., "#hashtags"). As a reminder, a module
tag defined in [RFC8819] is a string associated only with a module
name at the 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
SDOs and the Open Source community. These models 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, and security
management categories information at different locations in various
different ways. Let alone 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 a YANG module, which:
* Provide dictionary meaning for specific targeted data objects.
* Indicate relationship between data objects within the same YANG
module or from different YANG modules.
* Identify key performance metric data objects and the absolute
XPath expression identifying the element path to the node.
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The self describing data object tags can be used by the NETCONF/
RESTCONF 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 by means of <get-schema> operation. The self describing data
object tag capability can also be advertised using the 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 or assigned during the module
definition, assigned by implementations, or dynamically defined and
set by users.
This document defines a YANG module [RFC7950] which augments the
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 9).
Section 8 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].
The meaning of the symbols can be found in [RFC8340].
2. Terminology
2.1. Requirements Notation
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.
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2.2. Glossary
OPM Object Property Metric
3. Self Describing Data Object Tags: Massive Data Object Collection Use
Case
Among data object tags, the 'opm' (object, property, metric) tags can
be used to tackle massive data objects collection,indicate
relationship between data objects and only capture YANG data objects
associated with performance metrics data modelled with YANG
(Figure 1).
/----\
/Object\
| Tag |
\- +-/
+---------V--------+ have
| YANG Data Node <----------------+
| /Data Object 1 | |
+--^-------------^-+ |
|have |have |
| | |
+-------------+-----+ +-+-------------+ +-+-------------+
| YANG Data Node | | YANG Data Node| | YANG Data Node|
| /Data Object 2 | | /Data Object 3| | /Data Object 4|
+---^---------------+ +-^-------------+ +-^-------------+
| | |
| /-+-\ /-+-\
/-+--\ /Metric \ /Metric \
Property | Tag | | Tag |
\ Tag / \-^-/ \-^-/
\----/ | |
| /----\ |
| /Metric\ |
+----| Group +----|
\ Tag /
\- --/
Figure 1: The Relation between Object, Property and Metric
In Figure 1, data objects can contain other data objects called
subobjects. Both object and subobjects can be modeled as YANG data
nodes [RFC7950]. Data objects that contain other data objects can be
one of 'container', 'leaf-list', and 'list' and are tagged with
object tag. A subobject tagged with the property tag is a 'leaf'
node. Subobjects tagged with the metric tag can be one of
'container', 'leaf-list', 'list', or 'leaf' data node.
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A data object may contain one single object tag, or one single
property tag, or one single metric tag. In many cases, a data object
only contains one single metric tag. However the data object tagged
with the metric tag also can have one or multiple MetricType tags
and/or one single multi-source tag.
The use of 'opm' tags is meant 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 a single view of the data. In Figure 2, 'tunnel-
svc' data object is a container node defined in the 'tunnel-pm'
module and can be seen as the root object for property tagged
subobjects (e.g., 'tunnel-svc'/'create-time') and metric tagged
subobjects (e.g., 'tunnel-svc'/'avg-latency'). The 'name', 'create-
time', and 'modified-time' are property tagged subobjects under
'tunnel-svc' container. The 'avg-latency' and 'packet-loss' metrics
are tagged subobjects under 'tunnel-svc' container node. Consider
'tunnel-svc' data object and tunnel-svc/name data object as an
example, 'tunnel-svc' data object has one single object tag (i.e.,
'ietf:object') while tunnel-svc/name data object has one single
property subobject tag (i.e., 'ietf:property'). In addition, not all
metric subobjects need to be tagged, e.g., only specific category
such as loss-related metric subobjects need to be tagged with metric-
type tag which can further reduce amount data to be fetched.
+------------------------+--------------------------------------------+
| Data | Object Property Metric Module |
| Object | Tag Tag Tag Name |
+------------------------+--------------------------------------------+
| | 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 |
+------------------------+--------------------------------------------+
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Figure 2: Example of OPM Tags Used in the YANG Module
If data objects in 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.
4. Data Object Tag Values
All data object tags SHOULD begin with a prefix indicating who owns
their definition. To that aim, an IANA registry (Section 9.1) is
used to support registering data object tag prefixes. Three prefixes
are defined in the following subsections.
No further structure is imposed by this specification on the value
following the registered prefix other than 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 any structure they may require to their own tag values.
4.1. 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 Section 9.2.
4.2. 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
includes 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).
4.3. 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.
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4.4. 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).
5. Data Object Tag Management
Tags may be associated with a data object within a YANG module in a
number of ways. Typically, 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.
5.1. Module Design Tagging
A data object definition MAY indicate a set of data object tags to be
added by a module's implementer. These design time tags are
indicated using a set of extension statements which include:
opm-tag extension statement: Classifies management and operation
data into object, property subobject, and metric subobject
categories. Both object and subobjects can be modeled as YANG
data nodes [RFC7950]. Data objects that contain other data
objects can be one of 'container', 'leaf-list', and 'list' and are
tagged with object tag. A subobject tagged with the property tag
is a 'leaf' node. Subobjects tagged with the metric tag can be
one of 'container', 'leaf-list', 'list', or 'leaf' data node. A
data object contains one single object tag, one single property
tag, or one single metric tag. A data object tagged with metric
tag also can have one or multiple Metric type tag and/or one
single multi-source tag. See the examples depicted in Figure 2
and Figure 3.
metric-type extension statement: Provides metric data objects
classification (e.g., loss, jitter, delay, counter, gauge,
summary, unknown) within the YANG module.
multi-source-tag extension statement: Identifies multi-source
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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-type and multi-source-
tag extension statements are context information that 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 (Section 4.1). Thus, new data
object can drive the addition of new IETF tags to the IANA registry
defined in Section 9, and the IANA registry can serve as a check
against duplication.
5.2. 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.
5.3. 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.
6. Data Object Tags Module Structure
6.1. Data Object Tags Module Tree
The tree associated with the "ietf-data-object-tags" module is as
follows:
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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
7. YANG Module
<CODE BEGINS> file "ietf-data-object-tags@2021-05-03.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:benoit.claise@huawei.com>
Editor: Peng Liu <mailto:liupengyjy@chinamobile.com>
Editor: Zongpeng Du <mailto:duzongpeng@chinamobile.com>
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) 2021 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).
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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 2021-05-03 {
description
"Initial revision.";
reference
"RFC XXXX: Self Describing 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 object into object,
property, and metric three categories. Data Object can contain
other data objects called subobjects. Both object and subobjects
can be modeled as data nodes. The Data Object tagged with object
tag can be one of container, leaf-list and list. Data Object
tagged with the Property tag is a leaf node. Data Object tagged with
the Metric tag can be one of container, leaf-list, list, leaf.
Data objects tagged with either property tag or metric tag are
subobjects belonging to specific root data object. Each Data Object
may contain One single object tag or one single property tag, or
one single metric tag (These tags are mutually exclusive). As
such the origin of the value for the pre-defined tags should be set
to 'system'.";
}
extension metric-type {
argument tag;
description
"The argument 'tag' is of type 'tag'. The metric type can be
used to provide metric data object classification
(e.g., loss, jitter, packet loss,counter, gauge,
summary, unknown) 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.
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'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 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;
description
"The list of tags that should not be associated with the data
object within the YANG module. The user can remove (mask)
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tags from the operational state datastore 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>
8. Guidelines to Model Writers
This section updates [RFC8407].
8.1. 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).
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 9.2.
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9. IANA Considerations
9.1. YANG Data Object Tag Prefixes Registry
This document requests IANA to create a new registry entitled "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:
+----------+----------------------------------+-----------+----------+
| Prefix | Description | Reference | Assignee |
+----------+----------------------------------+-----------+----------+
| ietf: | IETF Tags allocated in the IANA | [This | IETF |
| | IETF YANG Data Object Tags | document] | |
| | registry | | |
| | | | |
| vendor: | Non-registered tags allocated by | [This | IETF |
| | the module's 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.
9.2. IETF YANG Data Object Tags Registry
This document requests IANA to create three new registries "IETF OPM
Tags","IETF Metric Type 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.
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Three registries are used to 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:
+----------------------------+--------------------------+-----------+
| OPM Tag | Description | Reference |
+----------------------------+--------------------------+-----------+
| | | |
| ietf:object |Represents Root object | [This |
| |containing other data |document] |
| |objects (e.g., interfaces)| |
| | | |
| ietf:property |Represents a property | [This |
| |data object(e.g., ifindex)| document] |
| |associated with a specific| |
| |root object (e.g., | |
| |interfaces) | |
| | | |
| ietf:metric |Represent metric data | [This |
| |object(e.g., ifstatistics)| document] |
| |associated with specific | |
| |root object(e.g., | |
| |interfaces) | |
+----------------------------+--------------------------+-----------+
+----------------------------+--------------------------+-----------+
| Metric Type Tag | Description | Reference |
+----------------------------+--------------------------+-----------+
| ietf:delay |Represents the delay metric |
| |group to which the metric | [This |
| |data objects belong to. | document] |
| | | |
| ietf:jitter |Represents the jitter metric [This |
| |group to which the metric |document] |
| |data objects belong to. | |
| | | |
| ietf:loss |Represents the loss metric| [This |
| |group to which the metric | document] |
| |data objects belong to. | |
| | | |
| ietf:counter |Represents any metric value |
| |associated with a metric | |
| |data object that monotonically[This |
| |increases over time, | document] |
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| |starting from zero. | |
| | | |
| ietf:gauge |Represents current | |
| |measurements associated | [This |
| |with a metric data object |document] |
| |that may increase, | |
| |decrease or stay constant.| |
| | | |
| ietf:summary |Represents the metric value [This |
| |associated with a metric | document |
| |data object that measures | |
| |distributions of discrete | |
| |events without knowing | |
| |predefined range. | |
| | | |
| ietf:unknown |Represents the metric value [This |
| |associated with metric | document |
| |data object that can not | |
| |determine the type of metric. |
+----------------------------+--------------------------+-----------+
+----------------------------+--------------------------+-----------+
| Multiple Source Tag | Description | Reference |
+----------------------------+--------------------------+-----------+
|ietf:agg |Relates to multiple sources [This |
| |aggregation type (i.e., | document] |
| |aggregated statistics) | |
| | | |
|ietf:non-agg |Relates to multiple sources [This |
| |aggregation type (i.e., | document] |
| |non-aggregated statistics)| |
+----------------------------+--------------------------+-----------+
Each YANG data object can have one 'opm' tag, zero or one metric-type
tag, zero or one multi-source tag.
9.3. Updates to the IETF XML Registry
This document requests IANA to register a new 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.
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9.4. Updates to the YANG Module Names Registry
This document requests IANA to register 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
maintained by IANA: N
10. Security Considerations
The YANG module specified in this document defines schema for data
that is designed to be accessed via network management protocols such
as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer
is the secure transport layer, and the mandatory-to-implement secure
transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer
is HTTPS, and the mandatory-to-implement secure transport is TLS
[RFC8446].
The Network Configuration Access Control Model (NACM) [RFC8341]
provides the means to restrict access for particular NETCONF or
RESTCONF users to a preconfigured subset of all available NETCONF or
RESTCONF protocol operations and content.
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.
11. 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, YingZhen Qu, Boyuan Yan.
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12. Contributors
Liang Geng
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing 10053
Email: gengliang@chinamobile.com
13. References
13.1. 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>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[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>.
[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>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[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>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
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[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>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC8819] Hopps, C., Berger, L., and D. Bogdanovic, "YANG Module
Tags", RFC 8819, DOI 10.17487/RFC8819, January 2021,
<https://www.rfc-editor.org/info/rfc8819>.
13.2. Informative References
[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>.
[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>.
[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 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 provided.
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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.
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<CODE BEGINS> file "ietf-data-object-tags-state@2021-05-03.yang"
module ietf-data-object-tags-state {
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:benoit.claise@huawei.com>
Editor: Peng Liu <mailto:liupengyjy@chinamobile.com>
Editor: Zongpeng Du <mailto:duzongpeng@chinamobile.com>
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) 2021 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 2021-05-03 {
description
"Initial revision.";
reference
"RFC XXXX: Self Describing Data Object Tags";
}
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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'.";
}
extension metric-type {
argument tag;
description
"The argument 'tag' is of type 'tag'.The metric-type can be
used to provide metric subobject classification
(e.g., loss, jitter, packet loss, guage, counter, histogram,
unknow, etc.) 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;
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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.";
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 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 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.";
}
}
}
}
}
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<CODE ENDS>
Appendix C. Targeted data object collection example
The following 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.
+-----------+ +-----------+
| 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 corresponding telemetry data
object capability model is created based on ietf-data-object-tags
module defined in this document.
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-type>loss</sec:metric-type>
</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.
Alternatively, the subscriber can query data object tag list from
somewhere(e.g., the network device, or offline document) using ietf-
data-object-tags module defined in this document and fetch tagged
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data objects 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.
<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.
Appendix D. Changes between Revisions
v03 - v04
* Remove histogram metric type tag from metric type tags.
* Clarify the object tag and property tag,metric tag are mutual
exlusive.
* Clarify to have two optional node tags (i.e.,object tag and
property tag) to indicate relationship between data objects.
* Update targeted data object collection example.
v02 - v03
* Additional Editorial changes.
* Security section enhancement.
* Nits fixed.
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v01 - v02
* Clarify the relation between data object, object tag, property tag
and metric tag in figure 1 and figure 2 and related description;
* Change Metric Group into Metric Type in the YANG model;
* Add 5 metric types in section 7.2;
v00 - v01
* Merge self describing data object tag use case section into
introduction section as a subsection;
* Add one glossary section;
* Clarify the relation between data object, object tag, property tag
and metric tag in Self Describing Data Object Tags Use Case
section;
* Add update to RFC8407 in the front page.
Authors' Addresses
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing
Jiangsu, 210012
China
Email: bill.wu@huawei.com
Benoit Claise
Huawei
De Kleetlaan 6a b1
1831 Diegem
Belgium
Email: benoit.claise@huawei.com
Peng Liu
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing
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Email: liupengyjy@chinamobile.com
Zongpeng Du
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing
Email: duzongpeng@chinamobile.com
Mohamed Boucadair
Orange
Rennes 35000
France
Email: mohamed.boucadair@orange.com
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