Skip to main content

An Architecture for YANG-Push to Message Broker Integration
draft-netana-nmop-yang-message-broker-integration-00

Document Type Active Internet-Draft (candidate for nmop WG)
Authors Thomas Graf , Ahmed Elhassany
Last updated 2024-04-22
Replaces draft-netana-nmop-yang-kafka-integration
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Formats
Additional resources Mailing list discussion
Stream WG state Call For Adoption By WG Issued
Document shepherd (None)
IESG IESG state I-D Exists
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-netana-nmop-yang-message-broker-integration-00
NMOP                                                             T. Graf
Internet-Draft                                              A. Elhassany
Intended status: Informational                                  Swisscom
Expires: 24 October 2024                                   22 April 2024

      An Architecture for YANG-Push to Message Broker Integration
          draft-netana-nmop-yang-message-broker-integration-00

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
   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 24 October 2024.

Graf & Elhassany         Expires 24 October 2024                [Page 1]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

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
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Document Scope  . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Origins of YANG-Push  . . . . . . . . . . . . . . . . . .   5
     1.4.  Origins of Apache Kafka . . . . . . . . . . . . . . . . .   5
   2.  Motivation  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     2.1.  Automatic Onboarding  . . . . . . . . . . . . . . . . . .   6
     2.2.  Preserve Schema . . . . . . . . . . . . . . . . . . . . .   6
     2.3.  Preserve Semantic Information . . . . . . . . . . . . . .   6
     2.4.  Standardize Data Processing Integration . . . . . . . . .   6
   3.  Elements of the Architecture  . . . . . . . . . . . . . . . .   6
     3.1.  YANG-Push Subscription  . . . . . . . . . . . . . . . . .   7
     3.2.  YANG-Push Publisher . . . . . . . . . . . . . . . . . . .  10
     3.3.  YANG-Push Receiver  . . . . . . . . . . . . . . . . . . .  12
     3.4.  YANG Schema Registry  . . . . . . . . . . . . . . . . . .  13
     3.5.  YANG Message Broker Producer  . . . . . . . . . . . . . .  14
     3.6.  YANG Message_Broker Consumer  . . . . . . . . . . . . . .  14
     3.7.  YANG Time Series Database Ingestion . . . . . . . . . . .  14
   4.  Project Milestones  . . . . . . . . . . . . . . . . . . . . .  14
   5.  Open Points . . . . . . . . . . . . . . . . . . . . . . . . .  15
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  16
   7.  Implementation Status . . . . . . . . . . . . . . . . . . . .  16
     7.1.  YANG Schema Registry Extension  . . . . . . . . . . . . .  16
     7.2.  YANG-Push Receiver Parsing Library  . . . . . . . . . . .  16
     7.3.  YANG Library Augmented-by Addition  . . . . . . . . . . .  17
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  17
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  17
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  19
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  21

Graf & Elhassany         Expires 24 October 2024                [Page 2]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

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 is needed to perform a data
   transformation to make a Message Broker and its data processing
   components with YANG notifications interoparable.

1.1.  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].

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.

   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.

Graf & Elhassany         Expires 24 October 2024                [Page 3]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   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

   *  Schema Registry

   *  Subject

Graf & Elhassany         Expires 24 October 2024                [Page 4]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

1.3.  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] has 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.

   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.

1.4.  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.

2.  Motivation

   There are four main objectives for native YANG-Push notifications and
   YANG Schema integration into a Message Broker.

Graf & Elhassany         Expires 24 October 2024                [Page 5]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

2.1.  Automatic Onboarding

   Automate the Data Mesh onboarding of newly subscribed YANG metrics.

2.2.  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 the user but also for an automated closed loop operation
   action.

2.3.  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.

2.4.  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.

3.  Elements of the Architecture

   The architecture consists of 6 elements.  Figure 1 gives an overview
   on the workflow.

Graf & Elhassany         Expires 24 October 2024                [Page 6]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   +------------------------------------------------------------+
   |                    Time Series Database                    |
   +------------------------------------------------------------+
                                  ^
                                  | (11) Ingest Data
                                  | According to Schema
   +------------------------------------------------------------+
   |                Time Series Database Ingestion              |
   +------------------------------------------------------------+
(9) Get  |  ^                                   ^ (8) Validate serialized Message
 Schema  |  |                                   | Against Schema on Consumer
         |  |                                   |
         |  |                                   |
         |  | (10) Issue                        | (7) Serialize YANG-Push Message
         v  | Schema             (5) Post       | annotated Schema ID
   +--------------------+          Schema  +--------------------+
   |       YANG         | <--------------  |  Data Collection   |
   |  Schema Registry   | -------------->  | YANG-Push Receiver |
   +--------------------+ (6) Issue        +--------------------+
                          Schema ID     (3) Get |  ^ (2) Receive YANG-Push
                                         Schema |  | Subscription Start Message
                                                |  |   ^
                                                |  |   |
                                                |  |   | (4) Publish YANG-Push
                                                v  |   | Message with Subscription ID
   +--------------------+                  +--------------------+
   |      Network       | (1) Subscribe    |   Network Node     |
   |   Orchestration    | ---------------> | YANG-Push Publisher|
   +--------------------+                  +--------------------+

                    Figure 1: End to End Workflow

   The workflow diagram (Figure 1) describes the steps from establishing
   the YANG-Push subscription to Time Series Database ingestion.

3.1.  YANG-Push Subscription

   With step number (1) in the workflow diagram, a YANG-Push
   subscription is according to Section 2.4 and 2.5 of [RFC8639]
   dynamically or statically configured, and with step (2) 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.

Graf & Elhassany         Expires 24 October 2024                [Page 7]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   [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 (1) and adds the
   module name, revision and revision-label information into the
   subscription state change notifications in step (2).

   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

Graf & Elhassany         Expires 24 October 2024                [Page 8]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

<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-interfaces">/if:interfaces</datastore-xpath-filter>
          <revision xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-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

Graf & Elhassany         Expires 24 October 2024                [Page 9]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   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 for the same subscription.

   {
     "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

3.2.  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.

Graf & Elhassany         Expires 24 October 2024               [Page 10]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   [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 (1) down to the
   Time Series Database Ingestion in step (11).

   [I-D.tgraf-netconf-yang-push-observation-time] adds observation-time
   or state-changed-observation-time in the YANG-Push push-update or
   push-change-update message, depending on wherever periodical or on-
   change subscription has been established.  observation-time describes
   when the operational metrics was obtained from the YANG datastore.
   Where state-changed-observation-time describes when the network state
   change was observed.

   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 for the same subscription.

{
  "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-yang-push-netobs-timestamping:observation-time": "2023-03-25T08:30:11.22Z",
      "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

Graf & Elhassany         Expires 24 October 2024               [Page 11]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   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 for the same subscription.

{
  "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-yang-push-netobs-timestamping:state-changed-observation-time": "2023-03-25T08:30:11.22Z",
      "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:subscriptions/subscription[id=2222]",
              "value": {
                "ietf-subscribed-notifications:encoding": "ietf-subscribed-notifications:encode-json",
                "ietf-yang-push:periodic": {
                  "period": 60000
                }
              }
            }
          ]
        }
      }
    }
  }
}

      Figure 5: JSON YANG-Push Example for a push-change-update
                         notification message

3.3.  YANG-Push Receiver

   For all the YANG modules and revisions of each 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 (3) in the workflow
   diagram.

Graf & Elhassany         Expires 24 October 2024               [Page 12]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   [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 Section 5.

3.4.  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 (6) 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

   curl http://localhost:8081/subjects/ ubjects/ | 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

Graf & Elhassany         Expires 24 October 2024               [Page 13]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

3.5.  YANG Message Broker Producer

   The previously issued Schema ID is prefixed to the previously in
   Section 3.3 described metadata augmented YANG push push-update
   message and serialized to a Message Broker topic in step (7) of the
   workflow diagram.

3.6.  YANG Message_Broker Consumer

   From the Message Broker topic the message is being consumed and the
   prefixed Schema ID is being used in step (9) of the workflow diagram
   to retrieve the YANG Schema to validate the Schema integrity of the
   message.

3.7.  YANG Time Series Database Ingestion

   The time series database ingestion specifications are being derived
   with the in Section 3.6 already retrieved Schema ID and YANG-Push
   push-update messages can be now ingested and indexed into the
   database table according to their schema.

4.  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:

Graf & Elhassany         Expires 24 October 2024               [Page 14]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   *  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.

5.  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]
      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.  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

Graf & Elhassany         Expires 24 October 2024               [Page 15]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

      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.

   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.

6.  Security Considerations

   TBD

7.  Implementation Status

   Note to the RFC-Editor: Please remove this section before publishing.

7.1.  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.

7.2.  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.

Graf & Elhassany         Expires 24 October 2024               [Page 16]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

7.3.  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].

   The source code can be obtained here: [YLA24] and was validated at
   the IETF 119 hackathon.

8.  Acknowledgements

   The authors would like to thank Yannick Buchs and Benoit Claise for
   their review and valuable comments.  Alex Huang Feng, Jean Quilbeuf
   and Zhuoyao Lin for review and contributing code and providing
   examples and inputs to the open points.

9.  References

9.1.  Normative References

   [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/>.

   [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-04, 21
              January 2024, <https://datatracker.ietf.org/doc/html/
              draft-ahuang-netconf-notif-yang-04>.

   [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-

Graf & Elhassany         Expires 24 October 2024               [Page 17]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

              notifications-versioning-04, 14 April 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              yang-notifications-versioning-04>.

   [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-03, 14 January 2024,
              <https://datatracker.ietf.org/doc/html/draft-tgraf-
              netconf-notif-sequencing-03>.

   [I-D.tgraf-netconf-yang-push-observation-time]
              Graf, T., Claise, B., and A. H. Feng, "Support of Network
              Observation Timestamping in YANG Notifications", Work in
              Progress, Internet-Draft, draft-tgraf-netconf-yang-push-
              observation-time-01, 14 April 2024,
              <https://datatracker.ietf.org/doc/html/draft-tgraf-
              netconf-yang-push-observation-time-01>.

   [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/>.

   [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>.

Graf & Elhassany         Expires 24 October 2024               [Page 18]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   [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>.

   [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>.

   [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>.

   [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>.

   [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>.

9.2.  Informative References

   [Atl15]    Hortonworks, "Apache Atlas", Apache Software Foundation,
              May 2015, <https://atlas.apache.org/>.

Graf & Elhassany         Expires 24 October 2024               [Page 19]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   [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-08, 6 October 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              distributed-notif-08>.

   [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-12, 21 January 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              udp-notif-12>.

   [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>.

Graf & Elhassany         Expires 24 October 2024               [Page 20]
Internet-Draft   YANG-Push to Message Broker Integration      April 2024

   [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>.

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

Graf & Elhassany         Expires 24 October 2024               [Page 21]