NETCONF Working Group Z. Wang
Internet-Draft Q. Wu
Intended status: Standards Track Huawei
Expires: September 4, 2020 P. Liu
H. Cai
China Mobile
March 3, 2020
Bulk Subscription to YANG Event Notification
draft-wang-netconf-bulk-subscribed-notifications-01
Abstract
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.
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 September 4, 2020.
Copyright Notice
Copyright (c) 2020 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Model Overview . . . . . . . . . . . . . . . . . . . . . . . 4
3. Bulk Subscription YANG Module . . . . . . . . . . . . . . . . 5
4. Bulk Notification YANG Module . . . . . . . . . . . . . . . . 8
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
5.1. Updates to the IETF XML Registry . . . . . . . . . . . . 9
5.2. Updates to the YANG Module Names Registry . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Normative References . . . . . . . . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
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.
o For a dynamic subscription, the subscriber may have already had
priori knowledge about correlation relation between
subscriptions(e.g., aggregated subscribed data from multiple
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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.
o 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.
o 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].
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].
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].
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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 to YANG Event
Notification has been split into two modules:
o 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.
o 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"
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to inform the corresponding recievers of compression algorithm to
be used by the publisher.
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 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? -> /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
3. Bulk Subscription YANG Module
<CODE BEGINS> 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
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"";
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";
}
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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
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"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.";
}
}
}
}
<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.
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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.;
}
}
<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:
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---------------------------------------------------------------------
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
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network operations. These are the subtrees and data nodes and their
sensitivity/vulnerability:
o /groups/group/group-id
o /groups/group/stream
o /sn:subscriptions/sn:subscription/sn:target/sn:stream/bs:group-id
o sn:establish-subscription/sn:input/sn:target/sn:stream /bs:group-
id
7. Acknowledgements
Thanks to Eric Voit for reviewing this draft and providing important
input to this document.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
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[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of
Documents Containing YANG Data Models", BCP 216, RFC 8407,
DOI 10.17487/RFC8407, October 2018,
<https://www.rfc-editor.org/info/rfc8407>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
8.2. Informative References
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
Authors' Addresses
Michael Wang
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: wangzitao@huawei.com
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Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
Peng Liu
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing 10053
Email: liupengyjy@chinamobile.com
Hui Cai
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing 10053
Email: caihui@chinamobile.com
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