Internet DRAFT - draft-tao-netconf-notif-node-tag-capabilities
draft-tao-netconf-notif-node-tag-capabilities
NETCONF Working Group Q. Wu
Internet-Draft Q. Ma
Intended status: Standards Track Huawei
Expires: May 2, 2021 P. Liu
Y. Fu
China Mobile
October 29, 2020
Self describing data Node tag capability
draft-tao-netconf-notif-node-tag-capabilities-03
Abstract
Before a client application subscribes to updates from a datastore,
server capabilities related to "Subscription to YANG Datastores" can
be advertised using YANG Instance Data format. These server
capabilities can be documented at implement time or reported at run-
time.
This document proposes a YANG module for self describing data Object
tag capability which augments system capabilities model and provide
additional self describing data node attributes associated with node
selectors within per-node capabilities.
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 2, 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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 . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Self-explanation data Node tag capability . . . . . . . . . . 3
2.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 4
3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
4.1. Updates to the IETF XML Registry . . . . . . . . . . . . 6
4.2. Updates to the YANG Module Names Registry . . . . . . . . 6
5. Security Considerations . . . . . . . . . . . . . . . . . . . 7
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.1. Normative References . . . . . . . . . . . . . . . . . . 7
7.2. Informative References . . . . . . . . . . . . . . . . . 9
Appendix A. Targeted data object subscription example . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction
As described in [I-D.netconf-notification-capabilities], a server
supporting YANG-Push MAY have a number of capabilities such as
o Supported (reporting) periods for periodic subscriptions;
o Maximum number of objects that can be sent in an update;
o Supported dampening periods for on-change subscriptions;
o The set of data nodes for which on-change notification is
supported.
Notification capability model defined in [I-D.netconf-notification-
capabilities] allows a client to discover basic system capability and
YANG-Push related capabilities both at implementation-time and run-
time. Without using this notification capability, it might lead to
unexpected failures or additional message exchanges for NETCONF
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clients to discover data objects with specific capability supported
by a NETCONF server.
When all telemetry data on the server subscribed by a particular
subscriber is huge, it becomes more likely that a burst of streamed
data may temporarily overwhelm a receiver and consume expensive
computing and storage resource. Accordingly, there is a need for
filtering subscribed telemetry data on a server based on server
capabilities, which can greatly reduce the amount of data to be
streamed out to the destination.
However without telemetry data classification or prior knowledge of
data objects correlation relationship, it is difficult for NETCONF
clients to automatically select target data objects that are of
interest to the client applications, e.g., identify a set of objects
from different YANG data modules which have a common characteristic,
collect specific object type nodes for multiple dimensional network
visibility analysis.
This document proposes a YANG module for self describing data Node
tag capability which augments System Capabilities model and provide
additional self describing data node tag attributes associated with
node selector for queries filtering.
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.
2. Self-explanation data Node tag capability
The YANG module ietf-notification-capabilities defined in [I-
D.netconf-notification-capabilities] specifies the following server
capabilities related to YANG Push:
o A set of capabilities related to the amount of notifications the
server can send out
o Specification of which data nodes support on-change notifications.
o Capability values can be specified on server level, datastore
level or on specific data nodes (and their contained sub-tree) of
a specific datastore. Capability values on a smaller, more
specific part of the server's data always override more generic
values.
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o On-change capability is not specified on a server level as
different datastores usually have different on-change
capabilities. On a datastore level on-change capability for
configuration and state data can be specified separately.
These server capabilities can be provided either at implementation
time or reported at run time.
This document augments system capabilities model and provide
additional data node self explaination tag attributes associated with
node selector within per-node capabilities:
o Specification of which data objects (e.g., data object tagged with
object tag, property subobject tag, metri subobject tag) they can
push to the target recipient;
o Specification of metric group tag associated with a set of metric
subobjects;
o Specfication of multi-source aggregation tag assocaited with
specific metric subobject;
2.1. Tree Diagram
The following tree diagram [RFC8340] provides an overview of the data
model.
module: ietf-self-describing-capabilities
augment /sysc:system-capabilities/sysc:datastore-capabilities/ +
sysc:per-node-capabilities/sys:node-selection/sys:node-selector:
+--ro self-describing-attributes
+--ro opm-tag* tags:tag
+--ro metric-group tags:tag
+--ro muli-source-tag tags:tag
3. YANG Module
<CODE BEGINS> file "ietf-self-describing-capabilities.yang"
module ietf-self-describing-capabilities {
yang-version 1.1;
namespace urn:ietf:params:xml:ns:yang:ietf-self-description-capabilities;
prefix sdc;
import ietf-system-capabilities { prefix sysc ; }
import ietf-module-tags { prefix tags; }
organization
"IETF NETMOD (Network Modeling) Working Group";
contact
"WG Web: <https://tools.ietf.org/wg/netconf/>
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WG List: <mailto:netconf@ietf.org>
Editor: Qin Wu
<mailto:bill.wu@huawei.com>
Qiufang Ma
<mailto:maqiufang1@huawei.com>
Peng Liu
<liupengyjy@chinamobile.com>
Hui Cai
<caihui@chinamobile.com>";
description
"This module defines an extension to System Capabilities model
and provides additional self explaination data node tag attributes
associated with node selector for queries filtering.
Copyright (c) 2020 IETF Trust and the persons identified as
authors of the code. 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 XXXX;
see the RFC itself for full legal notices.";
revision 2020-07-08 {
description
"Initial revision";
reference
"RFC XXXX";
}
augment "/sysc:system-capabilities/sysc:datastore-capabilities" +
"/sysc:per-node-capabilities" +
"/sysc:node-selection/sysc:node-selector" {
description "Allows per-node capabilities have additional self-explanation attributes";
container self-describing-attributes {
description "self describing attributes for specific data node.";
leaf-list opm-tag {
type tags:tag;
description
"Object, Property and Metric(OPM) Tags associated with
specific data object within YANG module.
See the IANA 'YANG Data Node Tag Prefixes' registry
for reserved prefixes and the IANA
'IETF YANG Data Node Tags' registry for IETF tags.";
}
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leaf metric-group {
type tags:tag;
description
"The metric-group can be used to provide correlation between
different performance metric information associated with YANG
data node.";
}
leaf multi-source-tag {
type tags:tag;
description
"The multiple source tag can be used to aggregate peformance
metric from different sources.";
}
}
}
}
<CODE ENDS>
4. IANA Considerations
4.1. Updates to the IETF XML Registry
This document registers a URI in the "IETF XML Registry" [RFC3688].
Following the format in [RFC3688], the following registration has
been made:
URI:
urn:ietf:params:xml:ns:yang:ietf-self-describing-capabilities
Registrant Contact:
The IESG.
XML:
N/A; the requested URI is an XML namespace.
4.2. Updates to the YANG Module Names Registry
This document registers one YANG module in the "YANG Module Names"
registry [RFC6020]. Following the format in [RFC6020], the following
registration has been made:
name:
ietf-self-describing-capabilities
namespace:
urn:ietf:params:xml:ns:yang:ietf-self-describing-capabilities
prefix:
sec
reference:
RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove
this note.)
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5. 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:
o /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-
node-capabilities/sys:node-selection/sys:node-selector/sec:self-
describing-attributes/sec:opm-tag
o /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-
node-capabilities/sys:node-selection/sys:node-selector/sec:self-
describing-attributes/sec:metric-group
o /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-
node-capabilities/sys:node-selection/sys:node-selector/sec:self-
describing-attributes/sec:multi-source-tag
6. Contributors
The authors would like to thank Ran Tao, Hui Cai for his major
contributions to the initial modeling and use cases.
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,
<https://www.rfc-editor.org/info/rfc2119>.
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[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>.
[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>.
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7.2. 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>.
Appendix A. Targeted data object subscription example
The following subsections provides targeted data object subscription
example. The subscription "id" values of 22 used below is just an
example. In production, the actual values of "id" might not be small
integers.
+-----------+ +-----------+
| Subscriber| | Publisher |
+------+----+ +-----+-----+
| |
| |
|Telemery data Tagging Advertisement
| (node-selector, opm-tag = metric)
|<---------------------------------|
| |
| establish-subscription |
| (datasore,node-selector) |
|--------------------------------->|
| |
| |
| |
| RPC Reply: OK, id = 22 |
|<---------------------------------|
| |
| |
| |
| Notification Message (for 22) |
| <--------------------------------|
| |
| |
| |
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The publisher advertise telemetry data node capability to the
subscriber to instruct the receiver to subscribe targeted data object
with specific characteristics (e.g., performance metric related data
object) and specific data path corresponding to the targeted data
object.
The following XML example [W3C.REC-xml-20081126] illustrates the
advertisment of the list of available target objects:
<?xml version="1.0" encoding="UTF-8"?>
<instance-data-set xmlns=\
"urn:ietf:params:xml:ns:yang:ietf-yang-instance-data">
<name>acme-router-notification-capabilities</name>
<content-schema>
<module>ietf-system-capabilities@2020-03-23</module>
<module>ietf-notification-capabilities@2020-03-23</module>
<module>ietf-data-export-capabilities@2020-03-23</module>
</content-schema>
<!-- revision date, contact, etc. -->
<description>Defines the notification capabilities of an acme-router.
The router only has running, and operational datastores.
Every change can be reported on-change from running, but
only config=true nodes and some config=false data from operational.
Statistics are not reported based on timer based trigger and counter
threshold based trigger.
</description>
<content-data>
<system-capabilities \
xmlns="urn:ietf:params:xml:ns:yang:ietf-system-capabilities" \
xmlns:inc=\
"urn:ietf:params:xml:ns:yang:ietf-notification-capabilities" \
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
<datastore-capabilities>
<datastore>ds:operational</datastore>
<per-node-capabilities>
<node-selector>\
/if:interfaces/if:interface/if:statistics/if:in-errors\
</node-selector>
<sec:self-describing-capabilities>
<sec:opm-tag>metric</sec:opm-tag>
<sec:metric-group>loss</sec:metric-group>
</sec:self-describing-capabilities>
</per-node-capabilities>
</datastore-capabilities>
</system-capabilities>
</content-data>
</instance-data-set>
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With telemetry data tagging information carried in the Telemetry data
Tagging Advertisement, the subscriber identifies targeted data object
and associated data path to the datastore node and sends a establish-
subscription RPC to subscribe specific data objects that are
interests to the client application from the publisher.
<netconf:rpc message-id="101"
xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">
<establish-subscription
xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"
xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">
<yp:datastore
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
ds:operational
</yp:datastore>
<yp:datastore-xpath-filter
xmlns:ex="https://example.com/sample-data/1.0">
/if:interfaces/if:interface/if:statistics/if:in-errors
</yp:datastore-xpath-filter>
<yp:periodic>
<yp:period>500</yp:period>
</yp:periodic>
</establish-subscription>
</netconf:rpc>
The publisher returns specific object type of operational state
related to the subscriber.
Authors' Addresses
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
Qiufang Ma
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: maqiufang1@huawei.com
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Peng Liu
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing 10053
Email: liupengyjy@chinamobile.com
Yuexia Fu
China Mobile
32 Xuanwumen West St, Xicheng District
Beijing 10053
Email: yuexiafu@chinamobile.com
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