draft-wang-netconf-bulk-subscribed-notifications-01.xml

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<rfc category="std"
     docName="draft-wang-netconf-bulk-subscribed-notifications-01"
     ipr="trust200902">
  <front>
    <title abbrev="Bulk Subscription">Bulk Subscription to YANG Event
    Notification</title>

    <author fullname="Michael Wang" initials="Z." surname="Wang">
      <organization>Huawei</organization>

      <address>
        <postal>
          <street>101 Software Avenue, Yuhua District</street>

          <city>Nanjing</city>

          <region>Jiangsu</region>

          <code>210012</code>

          <country>China</country>
        </postal>

        <email>wangzitao@huawei.com</email>
      </address>
    </author>

    <author fullname="Qin Wu" initials="Q." surname="Wu">
      <organization>Huawei</organization>

      <address>
        <postal>
          <street>101 Software Avenue, Yuhua District</street>

          <city>Nanjing</city>

          <region>Jiangsu</region>

          <code>210012</code>

          <country>China</country>
        </postal>

        <email>bill.wu@huawei.com</email>
      </address>
    </author>

    <author fullname="Peng Liu" initials="P." surname="Liu">
      <organization>China Mobile</organization>

      <address>
        <postal>
          <street>32 Xuanwumen West St, Xicheng District</street>

          <city>Beijing</city>

          <code>10053</code>
        </postal>

        <email>liupengyjy@chinamobile.com</email>
      </address>
    </author>

    <author fullname="Hui Cai" initials="H." surname="Cai">
      <organization>China Mobile</organization>

      <address>
        <postal>
          <street>32 Xuanwumen West St, Xicheng District</street>

          <city>Beijing</city>

          <code>10053</code>
        </postal>

        <email>caihui@chinamobile.com</email>
      </address>
    </author>

    <date year="2020"/>

    <area>OPS Area</area>

    <workgroup>NETCONF Working Group</workgroup>

    <abstract>
      <t>This document defines a YANG data model and associated mechanism that
      allows subscriber applications to bulk subscribe to publishers' event
      streams based on group identifier. This allows the publishers to report
      multiple notifications in a single bundling message.</t>
    </abstract>
  </front>

  <middle>
    <section anchor="intro" title="Introduction">
      <t>The Subscription to YANG Notifications specification [RFC8639] uses a
      "stream" name in subscription protocol operation for identifying the
      targeted event stream against which the subscription is applied and
      supports multiple subscriptions on a single transport session.
      Notification Message Headers and Bundles
      [I-D.ietf-netconf-notification-messages] allows multiple notifications
      bundled into one transportable message. However the subscription
      protocol operation doesn't provide specific criteria to classify
      subscriptions and therefore lacks the capability to explicitly indicate
      which specific subscription associated with the notification should be
      bundled together,e.g., subscription A and B are bundled based on their
      relationship with a set of YANG data models while subscription C and D
      are bundled based on "transport" and "encoding" parameters,both bundled
      groups are transported in the same transport session. A group identifier
      associated with a set of subscriptions or YANG data models enables the
      ability to perform encapsulation operation on a set of subscriptions
      with common characteristics via a single transaction. The group
      identifier provides a more optimal mechanism for notification
      encapsulation which would otherwise require multiple atomic transactions
      on a per subscription (i.e., one message per notification) basis.
      Following are some of the use-cases where such identifier can be
      used.<list style="symbols">
          <t>For a dynamic subscription, the subscriber may have already had
          priori knowledge about correlation relation between
          subscriptions(e.g., aggregated subscribed data from multiple
          sources). With this priori knowledge,it might send a bundle
          subscription RPC request to indicate what specific notifications
          associated with the subscription must be bundled together.</t>

          <t>For a configured subscription, self-explanation data Node tag
          capability advertisment describing correlation between data nodes in
          different YANG data model from different publisher can be used to
          further establish correlation relation between subscriptions. The
          correlation relation between subscriptions can be configured back
          onto publisher, which help determine which notifications can be
          bundles and which notifications are not.</t>

          <t>With the above bundle subscription indication from subscription
          to the publisher, multiple notifications corresponding to the
          request protocol operation for those notifications are bundled into
          one transportable message using Notification Message Headers and
          Bundles defined in [I-D.ietf-netconf-notification-messages].</t>
        </list></t>

      <t>This document defines a YANG data model and associated mechanism that
      classify subscription based on various different filtering criteria and
      allow subscriber applications to bulk subscribe/unsubscribe to
      publishers' event streams based on group identifier. This allows the
      publishers to report multiple notification in a single bundling message
      defined in [I-D.ietf-netconf-notification-messages].</t>

      <section title="Terminology">
        <t>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.</t>

        <t>This document uses the following terms:<list style="hanging">
            <t hangText="Event:">Something that happens which may be of
            interest or trigger the invocation of the rule. A fault, an alarm,
            a change in network state, network security threat, hardware
            malfunction, buffer untilization crossing a threshold, network
            connection setup, an external input to the system, for example
            [RFC3877].</t>

            <t hangText="Client:">Defined in [RFC8342].</t>

            <t hangText="Configuration: ">Defined in [RFC8342].</t>

            <t hangText="Configured subscription:">Defined in [RFC8639]</t>

            <t hangText="Configuration datastore:  ">Defined in [RFC8342].</t>

            <t hangText="Event record: ">A set of information detailing an
            event [RFC8639].</t>

            <t hangText="Event stream: ">A continuous, chronologically ordered
            set of events aggregated under some context [RFC8639].</t>

            <t hangText="Notification message: ">Information intended for a
            receiver indicating that one or more events have occurred
            [RFC8639].</t>

            <t hangText="Publisher:">An entity responsible for streaming
            notification messages per the terms of a subscription
            [RFC8639].</t>

            <t hangText="Receiver:">A target to which a publisher pushes
            subscribed event records. For dynamic subscriptions, the receiver
            and subscriber are the same entity [RFC8639].</t>

            <t hangText="Subscriber: ">A client able to request and negotiate
            a contract for the generation and push of event records from a
            publisher. For dynamic subscriptions, the receiver and subscriber
            are the same entity [RFC8639].</t>

            <t hangText="Subscription:">A contract with a publisher,
            stipulating the information that one or more receivers wish to
            have pushed from the publisher without the need for further
            solicitation [RFC8639].</t>
          </list></t>
      </section>
    </section>

    <!-- intro -->

    <section title="Model Overview">
      <t>The YANG data model for the Bulk Subscriptions to YANG Event
      Notification has been split into two modules:<list style="symbols">
          <t>The ietf-bulk-subscription.yang module defines a list for
          classifying different subscriptions corresponding to event streams
          into groups. Each group is associated with a group identifier and a
          set of subscriptions. A set of subscription is identified by a
          "group-id" string. This string is used both as an index within the
          bulk subscription module. It associate a specific bundle group with
          a group of subscriptions and a set of YANG data models, as shown in
          the subscription augmentation. In
          addition,ietf-subscribed-notifications.yang module defined in
          [RFC8639] is augmented with "max-bundle-latency" and
          "compression-algorithm" to enhance QoS feature and provide
          additional subscription bundle classification criteria.</t>

          <t>The ietf-bulk-notification.yang module augment the YANG structure
          of ietf-notification-messages.yang
          [draft-ietf-netconf-notification-messages], a "group-id" is added to
          the "message-header" of the ietf-notification-messages.yang to
          indicate the group to which a set of notifications belongs. In
          addition, "compression-algorithm" parameer is augmented to
          "message-header" to inform the corresponding recievers of
          compression algorithm to be used by the publisher.</t>
        </list></t>

      <t>The following tree diagrams [RFC8340] provide an overview of the data
      model for "ietf-bulk-subscription.yang" module and the
      "ietf-bulk-notification.yang" module.</t>

      <figure>
        <artwork>module: ietf-bulk-subscription
  +--rw bundle-groups
     +--rw bundle-group* [group-id]
        +--rw group-id    string
        +--rw subscription-id*     leafref 
        +--rw yang-module*         yang:yang-identifier 
  
  augment /sn:subscriptions/sn:subscription:
     +--rw max-bundle-latency      uint32
     +--rw compression-algorithm  string   
  +---x bundle-subscription
     +---input
        +---w group-id?        -&gt; /bundle-groups/bundle-group/group-id
        +---w max-bundle-latency      uint32
        +---w compression-algorithm   string
        +---w subscription-id*        subscription-id
        +---w masked-subscription-id* subscription-id

module: ietf-bulk-notification
     augment-structure /nm:message/nm:message-header:
        +--rw group-id?    string
        +--rw compression-algorithm string</artwork>
      </figure>
    </section>

    <section title="Bulk Subscription YANG Module">
      <figure>
        <artwork>  &lt;CODE BEGINS&gt; file "ietf-bulk-subscription@2019-09-23.yang"
module ietf-bulk-subscription {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-bulk-subscription";
  prefix bs;

  import ietf-subscribed-notifications {
    prefix sn;
  }
  import ietf-yang-types {
    prefix yang;
  }

  organization
    "IETF NETCONF (Network Configuration) Working Group";
  contact
    "";
  description
    "NETCONF Protocol Data Types and Protocol Operations.

     Copyright (c) 2011 IETF Trust and the persons identified as
     the document authors.  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
     (http://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC 6241; see
     the RFC itself for full legal notices.";

  revision 2019-09-23 {
    description
      "Initial revision";
       reference "RFC XXXX: Bulk Subscription to YANG Event Notification";
  }
  identity encode-cbor {
    base sn:encoding;
    description
      "Encode data using cbor.";
  }
  identity encode-gpb {
    base sn:encoding;
    description
      "Encode data using gpb.";
  }
  container bundle-groups {
    list bundle-group {
      key "group-id";
      leaf group-id {
        type string;
        description
          "This group ID is used as an index within the bulk subscription module
           , which indicates subscription classification criteria.";
      }
      leaf-list subscription-id {
        type leafref {
         path "/sn:subscriptions/sn:subscription/sn:id";
        }
        description
          "subscription-id";
      }
    leaf-list yang-module {
      type yang:yang-identifier;
      description
        "Name of the YANG module list supported by the publisher.";
    }
      description
        "List for group that classify different subscriptions into groups.";
    }
    leaf compression-algorithm {
      type string;
      description
        "The technology with which an originator compress bytestream 
         contents.";
    }
    description
      "Container for subscription group.";
  }
  augment "/sn:subscriptions/sn:subscription" {
      leaf max-bundle-latency {
      type uint32;
      units centiseconds;
      default 400;
      description
      "The maximum latency before a specific YANG Notifications generated 
       must egress a publisher.";  
     }
    leaf compression-algorithm {
      type string;
      description
        "The technology with which an originator compress bytestream 
         contents.";
    }
    description
      "Augment the subscribed-notifications module with transport specific inforamtion.";
  }

  rpc bundle-subscription {
   description
    "Bundle subscription. This paremeter indicates what subscription must be bundled together.";   
    input {
     leaf group-id {
      type string;
      description
      "This group ID is used as an index within the bulk subscription module";
      }
    leaf-list subscription-id {
      type uint32;
      description
       "Subscription-id paremeter indicates what subscription must be bundled together.";
      }
   leaf-list mask-subscription-id {
      type uint32;
      description
       "Mask subscription-id paremeter indicates what subscription must 
        not be bundled together.";
      } 
     leaf max-bundle-latency {
      type uint32;
      units centiseconds;
      default 400;
      description
      "The maximum latency before a specific YANG Notifications generated 
       must egress a publisher.";  
     }
    leaf compression-algorithm {
      type string;
      description
        "The technology with which an originator compress bytestream 
         contents.";
    }
    }
  }
}
&lt;CODE ENDS&gt;</artwork>
      </figure>
    </section>

    <section title="Bulk Notification YANG Module">
      <figure>
        <artwork>&lt;CODE BEGINS&gt; file "ietf-bulk-notification@2019-09-23.yang"
module ietf-bulk-notification {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-bulk-notification";
  prefix bn;

  import ietf-yang-structure-ext {
    prefix sx;
  }
  import ietf-notification-messages {
    prefix nm;
  }

  organization
    "IETF NETCONF (Network Configuration) Working Group";
  contact
    "";
  description
    "NETCONF Protocol Data Types and Protocol Operations.

     Copyright (c) 2011 IETF Trust and the persons identified as
     the document authors.  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
     (http://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC 6241; see
     the RFC itself for full legal notices.";

  revision 2019-09-23 {
    description
      "Initial revision";
    reference
      "RFC XXXX: Bulk Subscription to YANG Event Notification";
  }

  sx:augment-structure "/nm:message/nm:message-header" {
     leaf group-id {
      type string;
      description
        "To identify the group to which a set of notifications belongs.";
    }
    leaf compression-algorithm {
      type string;
      description
        "The technology with which an originator compress bytestream 
         contents.";
    }
    description
      "Group related informations are added to the 'message-header' of 
       the ietf-notification-messages to identify the group to which a 
       set of notifications belongs." and compression algorithms used by
       the publisher.;
  }
}
&lt;CODE ENDS&gt;</artwork>
      </figure>
    </section>

    <section title="IANA Considerations">
      <section anchor="xml" title="Updates to the IETF XML Registry">
        <t>This document registers two URIs in the IETF XML registry
        [RFC3688]. Following the format in [RFC3688], the following
        registrations are requested to be made:</t>

        <figure>
          <artwork>   ---------------------------------------------------------------------
      URI: urn:ietf:params:xml:ns:yang:ietf-bulk-subscription
      Registrant Contact: The IESG.
      XML: N/A, the requested URI is an XML namespace.

      URI: urn:ietf:params:xml:ns:yang:ietf-bulk-notification
      Registrant Contact: The IESG.
      XML: N/A, the requested URI is an XML namespace.
   ---------------------------------------------------------------------</artwork>
        </figure>
      </section>

      <section anchor="module"
               title="Updates to the YANG Module Names Registry">
        <t>This document registers two YANG modules in the YANG Module Names
        registry [RFC7950]. . Following the format in [RFC6020], the following
        registration has been made:</t>

        <figure>
          <artwork>   ---------------------------------------------------------------------
      Name:         ietf-bulk-subscription
      Namespace:    urn:ietf:params:xml:ns:yang:ietf-bulk-subscription
      Prefix:       trig
      Reference:    RFC xxxx

      Name:         ietf-bulk-notification
      Namespace:    urn:ietf:params:xml:ns:yang:ietf-bulk-notification
      Prefix:       evt
      Reference:    RFC xxxx
   ---------------------------------------------------------------------</artwork>
        </figure>
      </section>
    </section>

    <section anchor="security" title="Security Considerations">
      <t>The YANG module specified in this document defines a 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].</t>

      <t>The NETCONF 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.</t>

      <t>There are a number of data nodes defined in this YANG module that are
      writable/creatable/deletable (i.e., config true, which is the default).
      These data nodes may be considered sensitive in some network
      environments. Write operations (e.g., edit-config) to these data nodes
      without proper protection can have a negative effect on network
      operations. These are the subtrees and data nodes and their
      sensitivity/vulnerability:<list style="symbols">
          <t>/groups/group/group-id</t>

          <t>/groups/group/stream</t>

          <t>/sn:subscriptions/sn:subscription/sn:target/sn:stream/bs:group-id</t>

          <t>sn:establish-subscription/sn:input/sn:target/sn:stream
          /bs:group-id</t>
        </list></t>
    </section>

    <section title="Acknowledgements">
      <t>Thanks to Eric Voit for reviewing this draft and providing important
      input to this document.</t>
    </section>

    <!---->
  </middle>

  <back>
    <references title="Normative References">
      <?rfc include="reference.RFC.2119.xml"?>

      <?rfc include="reference.RFC.8174.xml"?>

      <?rfc include="reference.RFC.7950.xml"?>

      <?rfc include="reference.RFC.8342.xml"?>

      <?rfc include="reference.RFC.8407.xml"?>

      <?rfc include="reference.RFC.8126.xml"?>

      <?rfc include="reference.RFC.8040.xml"?>

      <?rfc include="reference.RFC.6241.xml"?>

      <?rfc include="reference.RFC.6242.xml"?>

      <?rfc include="reference.RFC.8341.xml"?>

      <?rfc include="reference.RFC.8446.xml"?>
    </references>

    <references title="Informative References">
      <?rfc include="reference.RFC.3688.xml"?>

      <?rfc include="reference.RFC.6020.xml"?>

      <?rfc include="reference.RFC.8340.xml"?>
    </references>
  </back>
</rfc>