Internet DRAFT - draft-tgraf-netconf-yang-push-observation-time
draft-tgraf-netconf-yang-push-observation-time
Network Working Group T. Graf
Internet-Draft Swisscom
Intended status: Standards Track B. Claise
Expires: 17 July 2024 Huawei
A. Huang Feng
INSA-Lyon
14 January 2024
Support of Network Observation Timestamping in YANG Notifications
draft-tgraf-netconf-yang-push-observation-time-00
Abstract
This document extends the YANG Notification header with the YANG
objects observation timestamping, both for the "push-update" and
"push-change-update" notifications.
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on 17 July 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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminologies . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Extend the Streaming Update Notifications . . . . . . . . . . 3
4. The "ietf-yang-push-netobs-timestamping" YANG Module . . . . 4
4.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 4
4.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
6.1. URI . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.2. YANG module name . . . . . . . . . . . . . . . . . . . . 11
7. Operational Considerations . . . . . . . . . . . . . . . . . 11
7.1. On Change Sync On Start . . . . . . . . . . . . . . . . . 11
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.1. Normative References . . . . . . . . . . . . . . . . . . 12
9.2. Informative References . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
To correlate network data among different Network Telemetry planes as
described in Section 3.1 of [RFC9232] or among different YANG push
subscription types defined in Section 3.1 of [RFC8641], network
observation timestamping describes when the state change was observed
or from when to when the data was accounted. This is essential for
understanding the timely relationship among these different planes
and YANG push subscription types.
With [I-D.tgraf-netconf-notif-sequencing] the delay between the YANG
Notification export and the arrival at the downstream system storing
the data can be measured. With network observation timestamping
described in this document, the delay between the network observation
and the data export of the YANG push publisher process can be
measured as well, extending the delay measurement scope from the time
the network observation and storing the data.
When the time bucket length in a time series database and the
periodical YANG push subscription time is identical, the eventTime of
the netconf notification message header is used for indexing, there
is variable delay between the observation time and the eventTime, and
the anchor-time as described in Section 4.2 of [RFC8641] is close to
the time bucket boundaries, a time bucket is going to have
periodically 0 or 2 measurements indexed instead of 1. Leading to
inconsistent accounting errors in the time series database. This
problem is resolved by using the observation-time instead of the
eventTime for time series database indexing.
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By extending the YANG Notification header with the YANG objects
observation-time for periodical and state-changed-observation-time
for on-change subscriptions these use cases can be addressed
accordingly.
2. Terminologies
The following terms are defined in [RFC8639] and are not redefined
here:
Publisher
Receiver
Subscription
In addition, this document defines the following terms:
Observation-time: Describes the measurement observation time for the
"push-update" notification in a "periodical" subscription.
State-changed-observation-time: Describes the time when the network
state change was observed.
3. Extend the Streaming Update Notifications
Besides the Subscription ID as described in Section 3.7 of [RFC8641],
the following network observation time metadata objects are part of
"push-update" and "push-change-update" notifications.
observation-time: Describes the measurement observation time for the
"push-update" notification in a "periodical" subscription. By
comparing the "observation-time" of two "push-update"
notifications, the collector can deduce the actual cadence of the
measurements, and compare it with the configured one.
state-changed-observation-time: Describes in the "push-change-
update" notification in a "on-change" subscription the time when
the network state change was observed after the subscription was
initially established. In case of an "on-change sync on start"
subscription it describes the time when the network state change
was observed before the subscription was established.
Figure 1 provides an example of a JSON encoded, [RFC8259], "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.
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{
"ietf-notification:notification": {
"eventTime": "2023-02-04T16:30:11.22Z",
"sysName": "example-router",
"sequenceNumber": 187653,
"ietf-yang-push:push-update": {
"id": 1011,
"observation-time": "2023-02-04T16:30:09.44Z",
"datastore-xpath-filter": "ietf-interfaces:interfaces",
"datastore-contents": {
"ietf-interfaces:interface": {
"name": {
"eth0": {
"oper-status": "up"
}
}
}
}
}
}
}
Figure 1: JSON Push Example for a subscription-modified
notification message
4. The "ietf-yang-push-netobs-timestamping" YANG Module
This YANG module augments the "ietf-yang-push" module with the
observation-time in the "push-update" and "push-change-update"
streaming update notifications.
4.1. Data Model Overview
4.1.1. Tree View
The following is the YANG tree diagram [RFC8340] for the ietf-yang-
push-netobs-timestamping YANG module
module: ietf-yang-push-netobs-timestamping
augment /yp:push-update:
+--ro observation-time? yang:date-and-time
augment /yp:push-change-update:
+--ro state-changed-observation-time? yang:date-and-time
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4.1.2. Full Tree View
The following is the YANG tree diagram [RFC8340] for the ietf-yang-
push-netobs-timestamping augmentation within the ietf-subscribed-
notifications, including the RPCs and notifications.
module: ietf-yang-push
augment /sn:establish-subscription/sn:input:
+---w (update-trigger)?
+--:(periodic)
| +---w periodic!
| +---w period centiseconds
| +---w anchor-time? yang:date-and-time
+--:(on-change) {on-change}?
+---w on-change!
+---w dampening-period? centiseconds
+---w sync-on-start? boolean
+---w excluded-change* change-type
augment /sn:establish-subscription/sn:input/sn:target:
+--:(datastore)
+-- datastore identityref
+-- (selection-filter)?
+--:(by-reference)
| +-- selection-filter-ref
| selection-filter-ref
+--:(within-subscription)
+-- (filter-spec)?
+--:(datastore-subtree-filter)
| +-- datastore-subtree-filter? <anydata>
| {sn:subtree}?
+--:(datastore-xpath-filter)
+-- datastore-xpath-filter? yang:xpath1.0
{sn:xpath}?
augment /sn:modify-subscription/sn:input:
+---w (update-trigger)?
+--:(periodic)
| +---w periodic!
| +---w period centiseconds
| +---w anchor-time? yang:date-and-time
+--:(on-change) {on-change}?
+---w on-change!
+---w dampening-period? centiseconds
augment /sn:modify-subscription/sn:input/sn:target:
+--:(datastore)
+-- datastore identityref
+-- (selection-filter)?
+--:(by-reference)
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| +-- selection-filter-ref
| selection-filter-ref
+--:(within-subscription)
+-- (filter-spec)?
+--:(datastore-subtree-filter)
| +-- datastore-subtree-filter? <anydata>
| {sn:subtree}?
+--:(datastore-xpath-filter)
+-- datastore-xpath-filter? yang:xpath1.0
{sn:xpath}?
augment /sn:subscription-started:
+--ro (update-trigger)?
+--:(periodic)
| +--ro periodic!
| +--ro period centiseconds
| +--ro anchor-time? yang:date-and-time
+--:(on-change) {on-change}?
+--ro on-change!
+--ro dampening-period? centiseconds
+--ro sync-on-start? boolean
+--ro excluded-change* change-type
augment /sn:subscription-started/sn:target:
+--:(datastore)
+-- datastore identityref
+-- (selection-filter)?
+--:(by-reference)
| +-- selection-filter-ref
| selection-filter-ref
+--:(within-subscription)
+-- (filter-spec)?
+--:(datastore-subtree-filter)
| +-- datastore-subtree-filter? <anydata>
| {sn:subtree}?
+--:(datastore-xpath-filter)
+-- datastore-xpath-filter? yang:xpath1.0
{sn:xpath}?
augment /sn:subscription-modified:
+--ro (update-trigger)?
+--:(periodic)
| +--ro periodic!
| +--ro period centiseconds
| +--ro anchor-time? yang:date-and-time
+--:(on-change) {on-change}?
+--ro on-change!
+--ro dampening-period? centiseconds
+--ro sync-on-start? boolean
+--ro excluded-change* change-type
augment /sn:subscription-modified/sn:target:
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+--:(datastore)
+-- datastore identityref
+-- (selection-filter)?
+--:(by-reference)
| +-- selection-filter-ref
| selection-filter-ref
+--:(within-subscription)
+-- (filter-spec)?
+--:(datastore-subtree-filter)
| +-- datastore-subtree-filter? <anydata>
| {sn:subtree}?
+--:(datastore-xpath-filter)
+-- datastore-xpath-filter? yang:xpath1.0
{sn:xpath}?
augment /sn:filters:
+--rw selection-filter* [filter-id]
+--rw filter-id string
+--rw (filter-spec)?
+--:(datastore-subtree-filter)
| +--rw datastore-subtree-filter? <anydata>
| {sn:subtree}?
+--:(datastore-xpath-filter)
+--rw datastore-xpath-filter? yang:xpath1.0
{sn:xpath}?
augment /sn:subscriptions/sn:subscription:
+--rw (update-trigger)?
+--:(periodic)
| +--rw periodic!
| +--rw period centiseconds
| +--rw anchor-time? yang:date-and-time
+--:(on-change) {on-change}?
+--rw on-change!
+--rw dampening-period? centiseconds
+--rw sync-on-start? boolean
+--rw excluded-change* change-type
augment /sn:subscriptions/sn:subscription/sn:target:
+--:(datastore)
+--rw datastore identityref
+--rw (selection-filter)?
+--:(by-reference)
| +--rw selection-filter-ref
| selection-filter-ref
+--:(within-subscription)
+--rw (filter-spec)?
+--:(datastore-subtree-filter)
| +--rw datastore-subtree-filter? <anydata>
| {sn:subtree}?
+--:(datastore-xpath-filter)
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+--rw datastore-xpath-filter?
yang:xpath1.0 {sn:xpath}?
rpcs:
+---x resync-subscription {on-change}?
+---w input
+---w id sn:subscription-id
notifications:
+---n push-update
| +--ro id? sn:subscription-id
| +--ro datastore-contents? <anydata>
| +--ro incomplete-update? empty
| +--ro ypnt:observation-time? yang:date-and-time
+---n push-change-update {on-change}?
+--ro id?
| sn:subscription-id
+--ro datastore-changes
| +--ro yang-patch
| +--ro patch-id string
| +--ro comment? string
| +--ro edit* [edit-id]
| +--ro edit-id string
| +--ro operation enumeration
| +--ro target target-resource-offset
| +--ro point? target-resource-offset
| +--ro where? enumeration
| +--ro value? <anydata>
+--ro incomplete-update? empty
+--ro ypnt:state-changed-observation-time?
yang:date-and-time
4.2. YANG Module
The YANG module has one leave augmenting the model of Subscription to
YANG Notifications [RFC8639].
<CODE BEGINS>
file "ietf-yang-push-netobs-timestamping@2023-03-06.yang"
module ietf-yang-push-netobs-timestamping {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-yang-push-netobs-timestamping";
prefix ypnt;
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
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}
import ietf-yang-push {
prefix yp;
reference
"RFC 8641: Subscription to YANG Notifications for Datastore Updates";
}
organization "IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http:/tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Authors: Thomas Graf
<mailto:thomas.graf@swisscom.com>
Benoit Claise
<mailto:benoit.claise@huawei.com>
Alex Huang Feng
<mailto:alex.huang-feng@insa-lyon.fr>";
description
"Defines YANG push event notification header with the observation
time in push-update and push-change-update notifications.
Copyright (c) 2023 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 Revised BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(https://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 2023-03-06 {
description
"First revision";
reference
"RFC XXXX: Support of YANG Notifications Observation Time";
}
feature yang-push-change-update-obs-timestamp {
description
"This feature indicates the YANG-push Notifications support
the observation timestamps in the push-change-update notifications.";
}
feature yang-push-update-obs-timestamp {
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description
"This feature indicates the YANG-push Notifications support
the observation timestamps in the push-update notifications.";
}
grouping yang-push-update-obs-timestamp {
description
"This grouping adds the start timestamp and the end timestamp of the
observed metrics.";
leaf observation-time {
type yang:date-and-time;
description
"This is the time when metrics started counting.";
}
}
grouping yang-push-change-update-obs-timestamp {
description
"This grouping adds the timestamp of the recorded event.";
leaf state-changed-observation-time {
type yang:date-and-time;
description
"This is the time when event happened.";
}
}
// Event notifications
augment "/yp:push-update" {
description
"This augmentation adds the start timestamp of the counted metrics
in the push-update notification.";
uses ypnt:yang-push-update-obs-timestamp;
}
augment "/yp:push-change-update" {
description
"This augmentation adds the timestamp of the event in the push-change-update
notification.";
uses ypnt:yang-push-change-update-obs-timestamp;
}
}
<CODE ENDS>
5. Security Considerations
The security considerations for the YANG notifications subscription
mechanism are described in [RFC8641]. This document adds no
additional security considerations.
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6. IANA Considerations
This document describes the URI used for the IETF XML Registry and
registers a new YANG module name.
6.1. URI
IANA is requested to add this document as a reference in the
following URI in the IETF XML Registry [RFC3688].
URI: urn:ietf:params:xml:ns:yang:ietf-yang-push-netobs-timestamping
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
Reference: RFC5277; RFC-to-be
6.2. YANG module name
This document registers the following YANG module in the YANG Module
Names Registry [RFC6020], within the "YANG Parameters" registry:
name: ietf-yang-push-netobs-timestamping
namespace:
urn:ietf:params:xml:ns:yang:ietf-yang-push-netobs-timestamping
prefix: ypnt
Reference: RFC-to-be
7. Operational Considerations
7.1. On Change Sync On Start
For "on-change sync on start" subscriptions, if the timestamp for the
network state change was observed before the subscription was
established and is not recorded in the YANG datastore, then no
timestamp should be populated to state-changed-observation-time.
8. Acknowledgements
The authors would like to thank Rob Wilton, Nick Corran, Pierre
Francois Ahmed Elhassany and Jean Quilbeuf for their review and
valuable comments.
9. References
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9.1. Normative 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>.
[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>.
9.2. Informative References
[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-13, 4 November 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
https-notif-13>.
[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-11, 11 October 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
udp-notif-11>.
[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-02, 6 October 2023,
<https://datatracker.ietf.org/doc/html/draft-tgraf-
netconf-notif-sequencing-02>.
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[RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", STD 90, RFC 8259,
DOI 10.17487/RFC8259, December 2017,
<https://www.rfc-editor.org/info/rfc8259>.
[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>.
[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>.
Authors' Addresses
Thomas Graf
Swisscom
Binzring 17
CH-8045 Zurich
Switzerland
Email: thomas.graf@swisscom.com
Benoit Claise
Huawei
Email: benoit.claise@huawei.com
Alex Huang Feng
INSA-Lyon
Lyon
France
Email: alex.huang-feng@insa-lyon.fr
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