NETCONF Working Group Z. Wang
Internet-Draft Q. Wu
Intended status: Standards Track Huawei
Expires: May 6, 2020 November 3, 2019

Bulk Subscription to YANG Event Notification
draft-wang-netconf-bulk-subscribed-notifications-00

Abstract

This document defines a YANG data model and associated mechanism that allows subscriber applications to bulk subscribe to publishers' event streams based on their requirements. And it also allows the publishers to report multiple event streams or subscriptions into a single notification message based on group identifier affiliation.

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 May 6, 2020.

Copyright Notice

Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.


Table of Contents

1. Introduction

The Subscription to YANG Notifications specification [RFC8639] uses A "stream" name in dynamic subscription protocol operation for identifying the targeted event stream against which the subscription is applied. Notification Message Headers and Bundles [I-D. ietf-netconf-notification-messages] uses subscription-id for identifying the targeted subscription. However the dynamic subscription protocol operation lack the capability to identify a set of event streams or a set of subscriptions which have a common characteristic. A group identifier associated with an event stream enables the ability to perform protocol operation on a set of event stream via a single transaction. The group identifier provides a more optimal mechanism for protocol operation which would otherwise require multiple atomic transactions on a per event stream basis. Following are some of the use-cases where such identifier can be used.

This document defines a YANG data model and associated mechanism that allows subscriber applications to bulk subscribe to publishers' event streams based on their requirements. And it also allows the publishers to report multiple event streams or subscriptions into a single notification message based on group identifier affiliation.

1.1. 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 uses the following terms:

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].
Client:
Defined in [RFC8342].
Configuration:
Defined in [RFC8342].
Configured subscription:
Defined in [RFC8639]
Configuration datastore:
Defined in [RFC8342].
Event record:
A set of information detailing an event [RFC8639].
Event stream:
A continuous, chronologically ordered set of events aggregated under some context [RFC8639].
Notification message:
Information intended for a receiver indicating that one or more events have occurred [RFC8639].
Publisher:
An entity responsible for streaming notification messages per the terms of a subscription [RFC8639].
Receiver:
A target to which a publisher pushes subscribed event records. For dynamic subscriptions, the receiver and subscriber are the same entity [RFC8639].
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].
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].

2. Model Overview

The YANG data model for the Bulk Subscriptions and Notifications has been split into two modules:

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.

module: ietf-bulk-subscription
  +--rw groups
     +--rw group* [group-id]
        +--rw group-id    string
        +--rw stream*     string

  augment /sn:subscriptions/sn:subscription/sn:target:
    +--:(stream-group)
       +--rw group-id?   -> /groups/group/group-id
  augment /sn:establish-subscription/sn:input/sn:target:
    +--:(stream-group)
       +-- group-id?   -> /groups/group/group-id


module: ietf-bulk-notification
     augment-structure /nm:message/nm:message-header:
       +--rw message-type identityref
       +--rw group-id?    string

3. Bulk Subscription YANG Module

  <CODE BEGINS> file "ietf-bulk-subscription@2019-10-14.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 2019-10-14 {
    description
      "Initial revision";
    reference
      "FOO";
  }

  container groups {
    list group {
      key "group-id";
      leaf group-id {
        type string;
        description
          "This group ID is used as an index within the bulk subscription module";
      }
      leaf-list stream {
        type string;
        description
          "A continuous, chronologically ordered set of events aggregated under some context";
      }
      description
        "List for group that classify different event streams into groups.";
    }
    description
      "Container for event stream group";
  }
  augment "/sn:subscriptions/sn:subscription/sn:target" {
   case stream-group {
    leaf group-id {
      type leafref {
        path "/bs:groups/bs:group/bs:group-id";
      }
      description
        "This group ID is used to associate subscription with a group of streams";
    }
    description
      "Augment the subscribed-notifications module with event stream group inforamtion.";
   }
  }
  augment "/sn:establish-subscription/sn:input/sn:target" {
   case stream-group {
    leaf group-id {
      type leafref {
        path "/bs:groups/bs:group/bs:group-id";
      }
      description
        "This group ID is used to associate subscription with a group of streams";
    }
    description
      "Augment the establish-subscription RPC with event stream group inforamtion.";
   }
  }
}

  <CODE ENDS>

4. Bulk Notification YANG Module

<CODE BEGINS> 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
      "FOO";
  }
  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.";
    }
    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.";
  }
}
<CODE ENDS>

5. IANA Considerations

5.1. Updates to the IETF XML Registry

This document registers two URIs in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registrations are requested to be made:

   ---------------------------------------------------------------------
      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.
   ---------------------------------------------------------------------

5.2. Updates to the YANG Module Names Registry

This document registers two YANG modules in the YANG Module Names registry [RFC7950]. . Following the format in [RFC6020], the following registration has been made:

   ---------------------------------------------------------------------
      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
   ---------------------------------------------------------------------

6. Security Considerations

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].

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.

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:

7. References

7.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011.
[RFC7950] Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016.
[RFC8040] Bierman, A., Bjorklund, M. and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017.
[RFC8126] Cotton, M., Leiba, B. and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K. and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018.
[RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018.

7.2. Informative References

[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010.
[RFC8340] Bjorklund, M. and L. Berger, "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018.

Authors' Addresses

Michael Wang Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China EMail: wangzitao@huawei.com
Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China EMail: bill.wu@huawei.com