An Architecture for YANG-Push to Message Broker Integration
draft-ietf-nmop-yang-message-broker-integration-04
| Document | Type | Active Internet-Draft (nmop WG) | |
|---|---|---|---|
| Authors | Thomas Graf , Ahmed Elhassany | ||
| Last updated | 2024-07-24 | ||
| Replaces | draft-netana-nmop-yang-message-broker-integration | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
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draft-ietf-nmop-yang-message-broker-integration-04
NMOP T. Graf
Internet-Draft A. Elhassany
Intended status: Informational Swisscom
Expires: 25 January 2025 24 July 2024
An Architecture for YANG-Push to Message Broker Integration
draft-ietf-nmop-yang-message-broker-integration-04
Abstract
This document describes the motivation and architecture of a native
YANG-Push notifications and YANG Schema integration into a Message
Broker and YANG Schema Registry.
Discussion Venues
This note is to be removed before publishing as an RFC.
Discussion of this document takes place on the Operations and
Management Area Working Group Working Group mailing list
(nmop@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/nmop/.
Source for this draft and an issue tracker can be found at
https://github.com/network-analytics/draft-daisy-kafka-yang-
integration/.
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
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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 25 January 2025.
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Copyright Notice
Copyright (c) 2024 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
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Origins of YANG-Push . . . . . . . . . . . . . . . . . . 3
1.2. Origins of Apache Kafka . . . . . . . . . . . . . . . . . 4
1.3. Document Scope . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 4
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Automatic Onboarding . . . . . . . . . . . . . . . . . . 6
3.2. Preserve Schema . . . . . . . . . . . . . . . . . . . . . 6
3.3. Preserve Semantic Information . . . . . . . . . . . . . . 6
3.4. Standardize Data Processing Integration . . . . . . . . . 6
4. Elements of the Architecture . . . . . . . . . . . . . . . . 6
4.1. YANG-Push Subscription . . . . . . . . . . . . . . . . . 8
4.2. YANG-Push Publisher . . . . . . . . . . . . . . . . . . . 10
4.3. YANG-Push Receiver . . . . . . . . . . . . . . . . . . . 13
4.4. YANG Schema Registry . . . . . . . . . . . . . . . . . . 13
4.5. YANG Message Broker Producer . . . . . . . . . . . . . . 14
4.6. YANG Message_Broker Consumer . . . . . . . . . . . . . . 14
4.7. YANG Data Consumer . . . . . . . . . . . . . . . . . . . 14
4.8. YANG Data Storage . . . . . . . . . . . . . . . . . . . . 14
5. Implementation Status . . . . . . . . . . . . . . . . . . . . 15
5.1. YANG Schema Registry Extension . . . . . . . . . . . . . 15
5.2. YANG-Push Receiver Parsing Library . . . . . . . . . . . 15
5.3. YANG Library Augmented-by Addition . . . . . . . . . . . 15
6. Security Considerations . . . . . . . . . . . . . . . . . . . 16
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.1. Normative References . . . . . . . . . . . . . . . . . . 16
8.2. Informative References . . . . . . . . . . . . . . . . . 18
Appendix A. Project Milestones . . . . . . . . . . . . . . . . . 21
Appendix B. Open Points . . . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
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1. Introduction
Nowadays network operators are using YANG [RFC7950] to model their
configurations and obtain YANG modelled data from their networks. It
is well understood that plain text are initially intended for humans
and need effort to make it machine readable due to the lack of
semantics. YANG modeled data is addressing most of these needs.
Increasingly more network operators organizing their data in a Data
Mesh [Deh22] where a Message Broker such as Apache Kafka [Kaf11] or
RabbitMQ [Rab07] facilitates the exchange of messages among data
processing components like a stream processor to filter, enrich,
correlate or aggregate, or a time series database to store data.
Even though YANG is intend to ease the handling of data, this promise
has not yet been fulfilled for Network Telemetry [RFC9232]. From
subscribing on a YANG datastore, publishing a YANG modeled
notifications message from the network and viewing the data in a time
series database, manual labor, such as obtaining the YANG schema from
the network and creating a transformation or ingestion specification
into a time series database, is needed to make a Message Broker and
its data processing components with YANG notifications interoparable.
Since YANG modules can change over time, for example when a router is
being upgraded to a newer software release, this process needs to be
adjusted contionously, leading often to errors in the data chain if
dependencies are not properly tracked and schema changes adjusted
simultaneously.
1.1. Origins of YANG-Push
With [RFC3535] the IAB set the requirements for Network Management in
2003. From these requirements NETCONF [RFC6241], NETCONF
Notifications [RFC5277] and RESTCONF [RFC8040] have been defined to
configure through <edit-config> and retrieve operational data through
<get> and NETCONF notifications through <notification> from a YANG
datastore on a network node.
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With YANG-Push, as defined in [RFC8639], [RFC8640] and [RFC8641],
periodical and on-change subscriptions to the YANG datastore can be
dynamically or statically configured. When notifications are
dynamically configured, messages are published over the initially
established NETCONF session, while when it is statically configured
messages are published through HTTPS-based
[I-D.ietf-netconf-https-notif] or UDP-based
[I-D.ietf-netconf-udp-notif] transport. Section 3.7 of [RFC8641]
describes push-update messages where the YANG subscribed data is
being published, where Section 2.7 of [RFC8639] describes the
subscription state change notifications where changes in the
subscription are being described.
1.2. Origins of Apache Kafka
Apache Kafka [Kaf11] is a Message Broker that supports producing and
consuming messages from so called topics. Each topic has one or more
partitions where messages are replicated or load balanced to scale
out. With the introduction of Confluent Schema Registry [Con18] a
topic can contain one or more subjects. A subject refers to a Schema
defining the structure of the message. The Schema then is used to
validate messages sent through topics and are identified by a Schema
ID. The Schema ID is issued when the Schema is registered to the
Confluent Schema Registry. Once the Schema ID is obtained, it can be
prefixed to the message with a Confluent Schema Registry compatible
serializer. Messages can then be validated against Schema at the
producer or at the consumer from a topic to ensure Schema integrity
of the message. The type of Schema evolution scheme can be defined
per subject, wherever non backward compatibility changes are allowed
or not.
1.3. Document Scope
This document focuses on YANG-Push [RFC8641] as the messaging
protocol between the network node and the Network Telemetry [RFC9232]
data collection. It describes the main components and the aimed
architecture for deploying such solution in a production network.
Then, it illustrates the integration of the YANG 1.1 [RFC7950] as a
schema modeling language into the Apache Kafka Message Broker and
Confluent Schema Registry [Con18].
2. Conventions and Definitions
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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2.1. Terminology
This document defines the following terms:
Message Broker: is an intermediary software component that translates
messages from the formal messaging protocol of the sender to the
formal messaging protocol of the receiver routed in topics. Message
brokers are elements in Data Mesh where software applications
communicate by exchanging formally-defined messages.
Stream Catalog: provides a single point of access that allows users
to centrally search semantics for information across a Message
Broker.
Additionally it makes use of the terms defined in [RFC8639], Apache
Kafka [Kaf11] and Confluent Schema Registry Documentation [ConDoc18].
The following terms are used as defined in [RFC8639]:
* Publisher
* Receiver
* Subscription
* Subscription ID
* Event stream filter
* Notification message
The following terms are used as defined in Apache Kafka Message
Broker [Kaf11]:
* Producer
* Consumer
* Topic
* Partition
The following terms are used as defined in Confluent Schema Registry
Documentation [ConDoc18]:
* Schema
* Schema ID
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* Schema Registry
* Subject
3. Motivation
There are four main objectives for native YANG-Push notifications and
YANG Schema integration into a Message Broker.
3.1. Automatic Onboarding
Automate the Data Mesh onboarding of newly subscribed YANG metrics.
3.2. Preserve Schema
The preservation of the YANG schema, that includes the YANG data
types as defined in [RFC6991] and the nested structure of the YANG
module, throughout the data processing chain ensures that metrics can
be processed and visualized as they were originally intended. Not
only for users but also for automated closed loop operation actions.
3.3. Preserve Semantic Information
[RFC7950] defines in Section 7.21.3 and 7.21.4 the description and
reference statement. This information is intended for the user,
describing in a human-readable fashion the meaning of a definition.
In Data Mesh, this information can be imported from the YANG Schema
Registry into a Stream Catalog where subjects within Message Broker
are identifiable and searchable. An example of a Stream Catalog is
Apache Atlas [Atl15]. It can also be applied for time series data
visualization in a similar fashion.
3.4. Standardize Data Processing Integration
Since the YANG Schema is preserved for operational metrics in the
Message Broker, a standardization for integration between network
data collection and stream processor or time series database is
implied.
4. Elements of the Architecture
The architecture consists of 6 elements. Figure 1 gives an overview
on the workflow.
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+------------------------------------------------------------+
| Data Storage |
+------------------------------------------------------------+
^
| (12) Ingest Data
| According to Schema
+------------------------------------------------------------+
| Data Consumer |
+------------------------------------------------------------+
(10) Get | ^ ^ (9) Validate
Schema | | | Serialized Message
| | | Schema on Consumer
| | |
| | +--------------------+
| | | Message |
| | | Broker |
| | +--------------------+
| | |
| | (11) Issue | (8) Serialize
| | | YANG-Push Message
| | | annotated Schema
v | Schema (6) Post | ID on Producer
+--------------------+ Schema +--------------------+
| YANG | <-------------- | Data Collection |
| Schema Registry | --------------> | YANG-Push Receiver |
+--------------------+ (7) Issue +--------------------+
Schema ID (4) Get | ^ (3) Receive
Schema | | YANG-Push
| | Subscription
| | Start Message
| | ^
| | |
| | | (5) Publish
| | | YANG-Push
| | | Message
| | | with
(1) Discover Notif. v | | Subscr. ID
+--------------------+ Capabilities +--------------------+
| Manage YANG-Push | ---------------> | Network Node |
| Subscription | (2) Subscribe | YANG-Push Publisher|
+--------------------+ ---------------> +--------------------+
Figure 1: End to End Workflow
The workflow diagram (Figure 1) describes the steps from establishing
the YANG-Push subscription to Data Storage ingestion.
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4.1. YANG-Push Subscription
With step number (1) in the workflow diagram, the YANG-Push
notification capabilities are being discovered according to Section 3
of [RFC9196], in with step (2) a YANG-Push subscription is according
to Section 2.4 and 2.5 of [RFC8639] dynamically or statically
configured, and with step (3) subscription state change notifications
are sent according to section 2.7 from the YANG-Push publisher to the
receiver to inform which event stream filter has been applied to
which subscription ID.
When the YANG-Push subscription is managed dynamically, the YANG data
is being received on the same NETCONF session where the subscription
is being maintained. With configured subscription the YANG data is
sent to the YANG-Push receiver through a separate transport session.
[I-D.ietf-netconf-yang-notifications-versioning] adds the capability
to subscribe to a specific YANG module revision or a YANG module
which needs to be backward compatible to in step (2) and adds the
module name, revision and revision-label information into the
subscription state change notifications in step (3).
Figure 2 provides and example how to create a YANG-Push configured
subscription with NETCONF in XML [W3C.REC-xml-20081126] with UDP-
based [I-D.ietf-netconf-udp-notif] transport
========== NOTE: '\' line wrapping per RFC 8792) ===========
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config>
<target>
<running/>
</target>
<config>
<subscriptions xmlns="urn:ietf:params:xml:ns:yang:ietf\
-subscribed-notifications">
<subscription>
<id>6666</id>
<datastore xmlns="urn:ietf:params:xml:ns:yang:ietf\
-yang-push"
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf\
-datastores">ds:operational</datastore>
<datastore-xpath-filter xmlns="urn:ietf:params:xml:ns\
:yang:ietf-yang-push"
xmlns:if="urn:ietf:params:xml:ns:yang:ietf-inter\
faces">/if:interfaces</datastore-xpath-filter>
<revision xmlns="urn:ietf:params:xml:ns:yang:ietf-yang\
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-push-revision">2018-02-20</revision>
<transport xmlns:unt="urn:ietf:params:xml:ns:yang:ietf\
-udp-notif-transport">unt:udp-notif</transport>
<encoding>encode-json</encoding>
<receivers>
<receiver>
<name>subscription-specific-receiver-def</name>
<receiver-instance-ref xmlns="urn:ietf:params:xml\
:ns:yang:ietf-subscribed-notif-receivers">\
global-udp-notif-receiver-def</receiver-instance-ref>
</receiver>
</receivers>
<periodic xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push">
<period>6000</period>
</periodic>
</subscription>
<receiver-instances xmlns="urn:ietf:params:xml:ns:yang:ietf\
-subscribed-notif-receivers">
<receiver-instance>
<name>global-udp-notif-receiver-def</name>
<udp-notif-receiver xmlns="urn:ietf:params:xml:ns:yang\
:ietf-udp-notif-transport">
<address>192.0.5.1</address>
<port>12345</port>
<enable-segmentation>false</enable-segmentation>
<max-segment-size/>
</udp-notif-receiver>
</receiver-instance>
</receiver-instances>
</subscriptions>
</config>
</edit-config>
</rpc>
Figure 2: NETCONF Example to establish configured subscription
Figure 3 provides an example of a JSON encoded, [RFC7951],
subscription-started state change notification message over HTTPS-
based [I-D.ietf-netconf-https-notif] or UDP-based
[I-D.ietf-netconf-udp-notif] transport with
[I-D.tgraf-netconf-notif-sequencing],
[I-D.tgraf-netconf-yang-push-observation-time] and
[I-D.ietf-netconf-yang-notifications-versioning] as extensions for
the same subscription.
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{
"ietf-notification:notification": {
"eventTime": "2023-03-25T08:30:11.22Z",
"ietf-notification-sequencing:sysName": "example-router",
"ietf-notification-sequencing:sequenceNumber": 1,
"ietf-subscribed-notification:subscription-started": {
"id": 6666,
"ietf-yang-push:datastore": "ietf-datastores:operational",
"ietf-yang-push:datastore-xpath-filter": "/if:interfaces",
"ietf-yang-push-revision:revision": "2014-05-08",
"ietf-yang-push-revision:module-name": "ietf-interfaces",
"ietf-yang-push-revision:revision-label": "",
"ietf-distributed-notif:message-observation-domain-id": [1,2],
"transport": "ietf-udp-notif-transport:udp-notif",
"encoding": "encode-json",
"ietf-yang-push:periodic": {
"ietf-yang-push:period": 100
}
}
}
}
Figure 3: JSON YANG-Push Example for a subscription-started
notification message
4.2. YANG-Push Publisher
With step number (4) in the workflow diagram, a YANG-Push push-update
or push-change-update message, depending on wherever periodical or
on-change subscription has been established, is sent from the YANG-
Push publisher to the receiver according to Section 3.7 of [RFC8639].
[I-D.ahuang-netconf-notif-yang] defines the NETCONF notification
header specified in [RFC5277] in YANG to enable JSON and CBOR
encoding.
[I-D.tgraf-netconf-notif-sequencing] adds sysName, messagePublisherId
and sequenceNumber in the NETCONF notification header to each message
to identify from which network node and publishing process, according
to [I-D.ietf-netconf-distributed-notif] a network node with
distributed architecture could have multiple messagePublisherId's,
the message has been published from. The sequenceNumber enables to
recognize loss from the YANG-Push publisher in step (2) down to the
Data Storage Ingestion in step (12).
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[I-D.tgraf-netconf-yang-push-observation-time] adds observation
timestamp and point-in-time in the YANG-Push push-update or push-
change-update message. observation timestamp contains the timestamp
and point-in-time when the metrics where observed. See Section 3 of
[I-D.tgraf-netconf-yang-push-observation-time] for more details.
Figure 4 provides an example of a JSON encoded, [RFC7951], push-
update notification message over HTTPS-based
[I-D.ietf-netconf-https-notif] or UDP-based
[I-D.ietf-netconf-udp-notif] transport with
[I-D.tgraf-netconf-notif-sequencing] and
[I-D.tgraf-netconf-yang-push-observation-time] as extensions for the
same subscription.
========== NOTE: '\' line wrapping per RFC 8792) ===========
{
"ietf-notification:notification": {
"eventTime": "2023-03-25T08:30:11.22Z",
"ietf-notification-sequencing:sysName": "example-router",
"ietf-notification-sequencing:sequenceNumber": 1,
"ietf-yang-push:push-update": {
"id": 6666,
"ietf-yp-observation:timestamp": \
"2023-03-25T08:30:11.22Z",
"ietf-yp-observation:point-in-time": \
"current-accounting",
"datastore-contents": {
"ietf-interfaces:interfaces": [
{
"interface": {
"name": "eth0",
"type": "iana-if-type:ethernetCsmacd",
"oper-status": "up",
"mtu": 1500
}
}
]
}
}
}
}
Figure 4: JSON YANG-Push Example for a push-update notification
message
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Figure 5 provides an example of a JSON encoded, [RFC7951], push-
change-update notification message over HTTPS-based
[I-D.ietf-netconf-https-notif] or UDP-based
[I-D.ietf-netconf-udp-notif] transport with
[I-D.tgraf-netconf-notif-sequencing] and
[I-D.tgraf-netconf-yang-push-observation-time] as extensions for the
same subscription.
========== NOTE: '\' line wrapping per RFC 8792) ===========
{
"ietf-notification:notification": {
"eventTime": "2023-03-25T08:30:11.22Z",
"ietf-notification-sequencing:sysName": "example-router",
"ietf-notification-sequencing:sequenceNumber": 1,
"ietf-yang-push:push-change-update": {
"id": 2222,
"ietf-yp-observation:timestamp": \
"2023-03-25T08:30:11.22Z",
"ietf-yp-observation:point-in-time": \
"state-changed",
"datastore-contents": {
"yang-patch": {
"patch-id": "patch_54",
"comment": "Changing encoding to JSON and increasing \
the period to 10 minutes",
"edit": [
{
"edit-id": "id_change_1",
"operation": "merge",
"target": "/ietf-subscribed-notifications\:subs\
criptions/subscription[id=2222]",
"value": {
"ietf-subscribed-notifications:encoding": \
"ietf-subscribed-notifications:encode-json",
"ietf-yang-push:periodic": {
"period": 60000
}
}
}
]
}
}
}
}
}
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Figure 5: JSON YANG-Push Example for a push-change-update
notification message
4.3. YANG-Push Receiver
For all the YANG modules and revisions of each sysName and
subscription ID in the subscription state change notification
received in step number (3) in the workflow diagram, all the YANG
module dependencies need to be determined through the YANG Library
[RFC8525], and then through NETCONF <get-schema> rpc calls according
to [RFC6022] all YANG modules need to be retrieved as described in
step (4) in the workflow diagram.
[I-D.lincla-netconf-yang-library-augmentation] extends the YANG
Library so that not only the submodule but also the augmentation list
can be obtained.
Figure 9 in Section 4.1 and YANG module in Section 5 of [RFC8641]
defines the payload of YANG-push notifications where "datastore-
contents" or the "value" of a "push-change-update") is "anydata".
[RFC7950] Section 7.10 states that anydata represents an unknown set
of nodes that can be modeled with YANG, and the model is not known at
design time and that the model of the unknown set of nodes can be
signaled through another protocol. This poses and issue in the
schema validation of YANG-Push notifications and will be further
clarified in point number (1) and (2) in Appendix B.
4.4. YANG Schema Registry
The schema registry SHOULD support YANG as the format for defining
schema. For each schema registered into the schema registry, a
schema ID is returned. That schema ID can be used when interacting
with the Message Broker to indicate the schema to use with the
message.”
Confluent Schema Registry is pluggable. Currently Supports AVRO,
JSON Schema and Protobuf. The YANG support is being developed at
[Yak24] as part of this architecture. Enable to register, obtain and
compare [YSR24] YANG Schemas. One YANG Schema with all its
augmentations is being registered per YANG-Push subscription ID. for
each YANG Schema a locally significant Schema ID is being issued as
described in step (7) in the workflow diagram.
curl -X POST -H "Content Type: application/vnd.schemaregistry.v1+json"
-d @ietf-interfaces@2018-02-20.json
http://localhost:8081/subjects/ietf-interfaces/
Figure 6: Register ietf-interfaces.yang into YANG Schema Registry
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curl http://localhost:8081/subjects/ subjects/ | jq
Figure 7: List all subjects YANG Schema Registry
curl http://localhost:8081/subjects/ietf-interfaces/versions
Figure 8: List versions of a given subject in YANG Schema Registry
curl http://localhost:8081/subjects/ietf-interfaces/versions/1
Figure 9: Retrieve schema of a specific subject and version in
YANG Schema Registry
4.5. YANG Message Broker Producer
The previously issued Schema ID is prefixed to the previously in
Section 4.3 described metadata augmented YANG push push-update
message and serialized to a Message Broker topic in step (8) of the
workflow diagram.
4.6. YANG Message_Broker Consumer
From the Message Broker topic the message is being consumed and the
prefixed Schema ID is being used in step (10) of the workflow diagram
to retrieve the YANG Schema to validate the Schema integrity of the
message.
In order to valida Schema integrity, the event stream filter of the
subscription ID in the subscription started or modified message is
needed to apply [I-D.aelhassany-anydata-validation] on the YANG
schema tree.
4.7. YANG Data Consumer
The data storage ingestion specifications are being derived with the
in Section 4.6 already retrieved Schema ID and YANG-Push push-update
messages can be now ingested and indexed into the data storage table
according to their schema in step (12).
4.8. YANG Data Storage
The YANG data is being ingested in step (12)according to the
previously defined ingestion specification and indexed with the
timestamp defined in observation timestamp as defined in
[I-D.tgraf-netconf-yang-push-observation-time]. A network operator
is now able to query the previously subscribed YANG data.
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5. Implementation Status
Note to the RFC-Editor: Please remove this section before publishing.
This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their
features. Readers are advised to note that other implementations may
exist.
According to [RFC7942], "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature.
It is up to the individual working groups to use this information as
they see fit".
5.1. YANG Schema Registry Extension
Ahmed Elhassany is developing a YANG Schema Extension in Confluent
Schema Registry.
The source code can be obtained here: [YSR24], the progress report
here: [YSRPR24], and was validated at the IETF 117 hackathon.
5.2. YANG-Push Receiver Parsing Library
Zhuoyao Lin developed as part of her internship a library to parse
YANG-Push subscription notifications, identify YANG module
dependencises with YANG Library [RFC8525] and obtain with NETCONF
<get-schema> rpc calls [RFC6022] all YANG modules from YANG-Push
publisher.
The source code can be obtained here: [LYP23] and was validated at
the IETF 117 hackathon.
5.3. YANG Library Augmented-by Addition
Zhuoyao Lin implemented
[I-D.lincla-netconf-yang-library-augmentation] in order to discover
augmented-by YANG modules in YANG Library [RFC8525].
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The source code can be obtained here: [YLA24] and was validated at
the IETF 119 hackathon.
6. Security Considerations
TBD
7. Acknowledgements
The authors would like to thank Yannick Buchs, Benoit Claise, Mohamed
Boucadair, Dhruv Dhody, Qin Wu, Andy Bierman, Feng Chong, Holger
Keller, Kristian Larsson and Ignacio Dominguez Martinez-Casanueva for
their review and valuable comments. Alex Huang Feng, Jean Quilbeuf
and huoyao Lin for review and contributing code and providing
examples and inputs to the open points.
8. References
8.1. Normative References
[I-D.aelhassany-anydata-validation]
Elhassany, A., "Validating anydata in YANG Library
context", Work in Progress, Internet-Draft, draft-
aelhassany-anydata-validation-01, 17 March 2024,
<https://datatracker.ietf.org/doc/html/draft-aelhassany-
anydata-validation-01>.
[I-D.ahuang-netconf-notif-yang]
Feng, A. H., Francois, P., Graf, T., and B. Claise, "YANG
model for NETCONF Event Notifications", Work in Progress,
Internet-Draft, draft-ahuang-netconf-notif-yang-05, 18
June 2024, <https://datatracker.ietf.org/doc/html/draft-
ahuang-netconf-notif-yang-05>.
[I-D.ietf-netconf-yang-notifications-versioning]
Graf, T., Claise, B., and A. H. Feng, "Support of
Versioning in YANG Notifications Subscription", Work in
Progress, Internet-Draft, draft-ietf-netconf-yang-
notifications-versioning-05, 16 June 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
yang-notifications-versioning-05>.
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[I-D.lincla-netconf-yang-library-augmentation]
Lin, Z., Claise, B., and I. D. Martinez-Casanueva,
"Augmented-by Addition into the IETF-YANG-Library", Work
in Progress, Internet-Draft, draft-lincla-netconf-yang-
library-augmentation-01, 4 March 2024,
<https://datatracker.ietf.org/doc/html/draft-lincla-
netconf-yang-library-augmentation-01>.
[I-D.tgraf-netconf-notif-sequencing]
Graf, T., Quilbeuf, J., and A. H. Feng, "Support of
Hostname and Sequencing in YANG Notifications", Work in
Progress, Internet-Draft, draft-tgraf-netconf-notif-
sequencing-06, 29 June 2024,
<https://datatracker.ietf.org/doc/html/draft-tgraf-
netconf-notif-sequencing-06>.
[I-D.tgraf-netconf-yang-push-observation-time]
Graf, T., Claise, B., and A. H. Feng, "Support of
Observation Timestamp in YANG-Push Notifications", Work in
Progress, Internet-Draft, draft-tgraf-netconf-yang-push-
observation-time-02, 3 July 2024,
<https://datatracker.ietf.org/doc/html/draft-tgraf-
netconf-yang-push-observation-time-02>.
[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>.
[RFC6022] Scott, M. and M. Bjorklund, "YANG Module for NETCONF
Monitoring", RFC 6022, DOI 10.17487/RFC6022, October 2010,
<https://www.rfc-editor.org/info/rfc6022>.
[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>.
[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>.
[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>.
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[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>.
[RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu,
"Handling Long Lines in Content of Internet-Drafts and
RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020,
<https://www.rfc-editor.org/info/rfc8792>.
[RFC9196] Lengyel, B., Clemm, A., and B. Claise, "YANG Modules
Describing Capabilities for Systems and Datastore Update
Notifications", RFC 9196, DOI 10.17487/RFC9196, February
2022, <https://www.rfc-editor.org/info/rfc9196>.
[RFC9254] Veillette, M., Ed., Petrov, I., Ed., Pelov, A., Bormann,
C., and M. Richardson, "Encoding of Data Modeled with YANG
in the Concise Binary Object Representation (CBOR)",
RFC 9254, DOI 10.17487/RFC9254, July 2022,
<https://www.rfc-editor.org/info/rfc9254>.
8.2. Informative References
[Atl15] Hortonworks, "Apache Atlas", Apache Software Foundation,
May 2015, <https://atlas.apache.org/>.
[Con18] Yokota, R., "Confluent Schema Registry", Confluent
Community and Apache Software Foundation, December 2018,
<https://github.com/confluentinc/schema-registry/>.
[ConDoc18] Yokota, R., "Confluent Schema Registry Documentation",
Confluent Community and Apache Software Foundation,
December 2018,
<https://docs.confluent.io/platform/current/schema-
registry/>.
[Deh22] Dehghani, Z., "Data Mesh", O'Reilly Media,
ISBN 9781492092391, March 2022,
<https://www.oreilly.com/library/view/data-
mesh/9781492092384/>.
[I-D.ietf-netconf-distributed-notif]
Zhou, T., Zheng, G., Voit, E., Graf, T., and P. Francois,
"Subscription to Distributed Notifications", Work in
Progress, Internet-Draft, draft-ietf-netconf-distributed-
notif-09, 28 April 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
distributed-notif-09>.
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[I-D.ietf-netconf-https-notif]
Jethanandani, M. and K. Watsen, "An HTTPS-based Transport
for YANG Notifications", Work in Progress, Internet-Draft,
draft-ietf-netconf-https-notif-15, 1 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
https-notif-15>.
[I-D.ietf-netconf-udp-notif]
Zheng, G., Zhou, T., Graf, T., Francois, P., Feng, A. H.,
and P. Lucente, "UDP-based Transport for Configured
Subscriptions", Work in Progress, Internet-Draft, draft-
ietf-netconf-udp-notif-14, 4 July 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
udp-notif-14>.
[Kaf11] Narkhede, N., "Apache Kafka", Apache Software Foundation,
January 2011, <https://kafka.apache.org/>.
[LYP23] Lin, Z., "libyangpush", Apache Software Foundation,
September 2023,
<https://github.com/network-analytics/libyangpush/>.
[Rab07] VMware, "RabbitMQ", Mozilla Public License, February 2007,
<https://rabbitmq.com/>.
[RFC3535] Schoenwaelder, J., "Overview of the 2002 IAB Network
Management Workshop", RFC 3535, DOI 10.17487/RFC3535, May
2003, <https://www.rfc-editor.org/info/rfc3535>.
[RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event
Notifications", RFC 5277, DOI 10.17487/RFC5277, July 2008,
<https://www.rfc-editor.org/info/rfc5277>.
[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>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016,
<https://www.rfc-editor.org/info/rfc7942>.
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[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/info/rfc7951>.
[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>.
[RFC8525] Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K.,
and R. Wilton, "YANG Library", RFC 8525,
DOI 10.17487/RFC8525, March 2019,
<https://www.rfc-editor.org/info/rfc8525>.
[RFC8640] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
E., and A. Tripathy, "Dynamic Subscription to YANG Events
and Datastores over NETCONF", RFC 8640,
DOI 10.17487/RFC8640, September 2019,
<https://www.rfc-editor.org/info/rfc8640>.
[RFC9232] Song, H., Qin, F., Martinez-Julia, P., Ciavaglia, L., and
A. Wang, "Network Telemetry Framework", RFC 9232,
DOI 10.17487/RFC9232, May 2022,
<https://www.rfc-editor.org/info/rfc9232>.
[W3C.REC-xml-20081126]
Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and
F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth
Edition)", World Wide Web Consortium Recommendation REC-
xml-20081126, November 2008,
<https://www.w3.org/TR/2008/REC-xml-20081126>.
[Yak24] Feng, F., "Yangkit", Apache Software Foundation, February
2024, <https://github.com/yang-central/yangkit/>.
[YLA24] Lin, Z., "libyangpush", Apache Software Foundation, March
2024, <https://github.com/Zephyre777/draft-lincla-netconf-
yang-library-augmentation/>.
[YSR24] Elhassany, A., "YANG Schema Registry Extension", Apache
Software Foundation, February 2024,
<https://github.com/confluentinc/schema-registry-yang-
format/>.
[YSRPR24] Elhassany, A., "YANG Schema Registry Extension Progress
Report", February 2024, <https://github.com/network-
analytics/draft-daisy-kafka-yang-integration/blob/main/
YANG%20Schema%20registry%20integration.pdf>.
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Appendix A. Project Milestones
IETF 115:
* Official Project Kickoff.
* [I-D.ietf-netconf-yang-notifications-versioning] extends schema
reference in subscription state change notification.
IETF 116:
* YANG module with augmentations can be registered in Confluent
Schema Registry with YANG extension [Yak24].
* [I-D.tgraf-netconf-notif-sequencing] extends NETCONF notification
header with sysName, messagePublisherId and sequenceNumber.
* [I-D.tgraf-netconf-yang-push-observation-time] extends YANG-Push
push-update or push-change-update message with observation-time or
state-changed-observation-time.
* [I-D.ahuang-netconf-notif-yang] defines the NETCONF notification
header specified in [RFC5277] in YANG.
IETF 118:
* All relevant YANG modules for a subscribed xpath can be determined
through the YANG Library [RFC8525] and retrieved throug NETCONF
<get-schema> rpc calls according to [RFC6022]. Gap in YANG
library addressed in
[I-D.lincla-netconf-yang-library-augmentation].
IETF 119:
* [I-D.aelhassany-anydata-validation] addresses that anydata modeled
nodes can be validated with YANG Library RFC 8525. 6WIND VSR and
Huawei VRP YANG-Push publisher and open-source
[I-D.lincla-netconf-yang-library-augmentation] implementation
validated at hackathon.
IETF 120:
* 6WIND VSR, Huawei VRP and Cisco IOS XR YANG-Push publisher and
[I-D.aelhassany-anydata-validation] implementation validated at
hackathon.
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* [I-D.tgraf-netconf-yang-push-observation-time] merges both
timestamps for periodical and on-change YANG-Push subscriptions
into one observation timestamp and adding a decleration point-in-
time to describe when the observation was observed.
Appendix B. Open Points
Lists all current open points to be either further researched and
clarified or tested with running code.
Note to the RFC-Editor: Please remove this section before publishing.
Open Point 1:
Figure 9 in Section 4.1 and YANG module in Section 5 of [RFC8641]
define the payload of YANG-push notifications where "datastore-
contents" or the "value" of a "push-change-update") is "anydata".
[RFC7950] Section 7.10 states that anydata represents an unknown
set of nodes that can be modeled with YANG, and the model is not
known at design time and that the model of the unknown set of
nodes can be signaled through another protocol. How to exchange
the anydata modeled nodes between the YANG-Push publisher and the
receiver given that the data nodes contained in anydata subtree is
potentially incomplete (filtered out by xpath or subtree). How
can a YANG-Push receiver validate the content of anydata nodes?
[I-D.aelhassany-anydata-validation] addresses this by using YANG
Library [RFC8525] as mechanism to exchange the YANG model of the
nodes contained in anydata.
Open Point 2:
The NETCONF Notification structure is defined in [RFC5277] using a
XSD Schema. For YANG-push [RFC8641], this XSD Schema has been
proposed using YANG 1.1 [RFC7950] modeling language in
[I-D.ahuang-netconf-notif-yang]. Examples of notifications
encoded in XML are provided in Section 5 of [RFC5277]. In YANG-
JSON [RFC7951], the specification does not provide any examples on
how notifications should be encoded. In YANG-CBOR [RFC9254],
notifications are considered "container-like" instances and
examples does not show consistency with XML-based and YANG-JSON
encoding notifications. Assumptions are being made in
[I-D.ahuang-netconf-notif-yang] providing examples of YANG-JSON
and YANG-CBOR encoded notifications. The notification structure
needs consistency accross YANG encodings. Confirm findings and
propose how to be addressed.
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Open Point 3:
Test with running code wherever with
[I-D.ietf-netconf-yang-notifications-versioning] and
[I-D.lincla-netconf-yang-library-augmentation] all datastore-
subtree-filter or datastore-xpath-filter referenced YANG modules
and their dependencies can be fully indentified.
Authors' Addresses
Thomas Graf
Swisscom
Binzring 17
CH-8045 Zurich
Switzerland
Email: thomas.graf@swisscom.com
Ahmed Elhassany
Swisscom
Binzring 17
CH- Zuerich 8045
Switzerland
Email: ahmed.elhassany@swisscom.com
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