| Internet-Draft | Data Export Capability | October 2020 |
| Wu, et al. | Expires 2 May 2021 | [Page] |
This document proposes a YANG module for telemetry data export capability which augments system Capabilities model and provides additional telemetry data export attributes associated with system capability for transport dependent capability negotiation.¶
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This Internet-Draft will expire on 2 May 2021.¶
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 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.¶
Notification capability model defined in [I-D.netconf-notification-capabilities] allows a client to discover a set of capabilities supported by the server (e.g., basic system capability and YANG-Push related capabilities) both at implementation-time and run-time. These "capabilities" permit the client to adjust its behavior to take advantage of the features exposed by the device.¶
However pre-configuration for some transport specific parameters (e.g., transport protocol, encoding format, encryption by the client is still inevitable, which may cause unexpected failure and additional message exchange between client and server.¶
This document proposes a YANG module for telemetry data export capability which augments System Capabilities model and provide additional data export attributes for transport dependent capability negotiation.¶
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.¶
The YANG module ietf-notification-capabilities defined in [I-D.netconf-notification-capabilities] specify the following server capabilities related to YANG Push:¶
These server capabilities are transport independent and session level capabilities and can be provided either at implementation time or reported at run time.¶
This document augments system Capabilities model and provides additional data export attributes associated with system capabilities:¶
The following tree diagram [RFC8340] provides an overview of the data model.¶
module: ietf-data-export-capabilities
augment /sysc:system-capabilities:
+--ro data-export-capabilities
+--ro transport-protocol? identityref
+--ro encoding-format? identityref
+--ro security-protocol? identityref
+--ro compression-mode? identityref
augment /sysc:system-capabilities/inc:subscription-capabilities:
+--ro data-export-capabilities
+--ro message-bundling-support? boolean
augment /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-node-capabilities:
+--ro data-export-capabilities
+--ro adaptive-interval-support boolean
+--ro timer-event-support? boolean
+--ro counter-threshold-support? boolean
+--ro suppress-redundant? boolean¶
<CODE BEGINS> file "ietf-data-export-capabilities.yang"
module ietf-data-export-capabilities {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities";
prefix dec;
import ietf-system-capabilities {
prefix sysc;
}
import ietf-notification-capabilities {
prefix inc;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <https://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Editor: Qin Wu
<mailto:bill.wu@huawei.com";
description
"This module defines an extension to System Capability and YANG Push
Notification Capabilities model and provides additional data export
attributes for transport dependent capability negotiation.
Copyright (c) 2019 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 2020-07-03 {
description
"Initial revision.";
reference
"RFC XXXX: Telemetry Data Export capability";
}
identity transport-protocol {
description
"Base identity for transport protocol type.";
}
identity tcp {
base transport-protocol;
description
"Identity for tcp transport protocol.";
}
identity udp {
base transport-protocol;
description
"Identity for udp transport protocol.";
}
identity grpc {
base transport-protocol;
description
"Identity for grpc transport protocol.";
}
identity security-protocol {
description
"Base identity for security protocol type.";
}
identity tls {
base security-protocol;
description
"Identity for tls security protocol.";
}
identity ssh {
base security-protocol;
description
"Identity for ssh transport protocol.";
}
identity encoding-format {
description
"Base identity for encoding format type.";
}
identity xml {
base encoding-format;
description
"Identity for xml encoding format.";
}
identity json {
base encoding-format;
description
"Identity for json encoding format.";
}
identity gpb {
base encoding-format;
description
"Identity for gpb encoding format.";
}
identity cbor {
base encoding-format;
description
"Identity for cbor encoding format.";
}
identity compression-mode {
description
"Base identity for compression mode.";
}
identity gzip {
base security-protocol;
description
"Identity for gzip compression mode.";
}
identity deflate {
base security-protocol;
description
"Identity for deflate compression mode.";
}
identity subscription-mode {
description
"Base identity for subscription mode.";
}
identity periodic {
base subscription-mode;
description
"Identity for periodic subscription mode.";
}
identity on-change {
base subscription-mode;
description
"Identity for on change subscription mode.";
}
identity event {
base subscription-mode;
description
"Identity for event based subscription mode.";
}
typedef centiseconds {
type uint32;
description
"A period of time, measured in units of 0.01 seconds.";
}
augment "/sysc:system-capabilities" {
description
"Add system level capability.";
container data-export-capabilities {
description
"Capabilities related to telemetry data export capability negotiation.";
leaf transport-protocol {
type identityref {
base transport-protocol;
}
description
"Type of transport protocol.";
}
leaf encoding-format {
type identityref {
base encoding-format;
}
description
"Type of encoding format.";
}
leaf security-protocol {
type identityref {
base security-protocol;
}
description
"Type of secure transport.";
}
leaf compression-mode {
type identityref {
base compression-mode;
}
description
"Type of compression mode.";
}
}
}
augment "/sysc:system-capabilities/inc:subscription-capabilities" {
description
"Add subscription level capability.";
container data-export-capabilities {
description
"Capabilities related to telemetry data export capability negotiation.";
leaf message-bundling-support {
type boolean;
default "false";
description
"Enables message bundling support.";
}
}
}
augment "/sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-node-capabilities" {
description
"Add datastore and node level capability.";
container data-export-capabilities {
description
"Capabilities related to telemetry data export capability negotiation.";
leaf adaptive-interval-support {
type boolean;
default "false";
description
"Set to true if one event stream supports multiple period intervals and
allows period interval switching. Set to false if the event stream doesn't
support period interval switching.";
}
leaf timer-event-support {
type boolean;
default "false";
description
"Set to true if timer event is supported, i.e.,, schedule a specific event
periodically with specified start time, duration, repeat option, repeat
interval.";
}
leaf counter-threshold-support {
type boolean;
default "false";
description
"Set to true if the subscription mode is event based
subscription mode and counter based trigger is support
(i.e., named counter crosses a specified threshold).
Set to false if event based subscription mode is not
supported.";
}
leaf suppress-redundant {
type boolean;
default "false";
description
"Suppress dupplicated data objects to be sent during each update interval.";
}
}
}
}
<CODE ENDS>¶
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-data-export-capabilities
Registrant Contact:
The IESG.
XML:
N/A; the requested URI is an XML namespace.¶
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-data-export-capabilities
namespace:
urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities
prefix:
dec
reference:
RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove
this note.)¶
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:¶
The authors would like to thank Ran Tao for his major contributions to the initial modeling and use cases.¶
The following instance-data example describes the notification capabilities of a hypothetical "acme-router". The router implements the 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. Interface statistics are reported only when both adaptive-interval-support and count-threshold-support are set to true.¶
<CODE BEGINS> file "acme-router-notification-capabilities.xml"
========== NOTE: '\' line wrapping per BCP YYY (RFC YYYY) ===========
<?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\
</node-selector>
<inc:subscription-capabilities>
<inc:minimum-dampening-period>5
</inc:minimum-dampening-period>
<inc:on-change-supported>\
state-changes\
</inc:on-change-supported>
</inc:subscription-capabilities>
</per-node-capabilities>
<per-node-capabilities>
<node-selector>\
/if:interfaces/if:interface/if:statistics/if:out-octets\
</node-selector>
<dec:data-export-capabilities>
<dec:adaptive-interval-support>false</dec:adaptive-interval-support>
<dec:threshold-event-support>false</dec:threshold-event-support>
</dec:data-export-capabilities>
</per-node-capabilities>
</per-node-capabilities>
<per-node-capabilities>
<node-selector>\
/if:interfaces/if:interface/if:statistics/if:in-errors\
</node-selector>
<dec:data-export-capabilities>
<dec:adaptive-interval-support>true</dec:adaptive-interval-support>
<dec:threshold-event-support>true</dec:threshold-event-support>
</dec:data-export-capabilities>
</per-node-capabilities>
</datastore-capabilities>
</system-capabilities>
</content-data>
</instance-data-set>
<CODE ENDS>¶
The client configure adaptive subscription parameters on the server. The adaptive subscription configuration parameters require the server to scan all interface of specific type every 5 seconds up to 30 seconds if the value of interface in-errors is greater than 1000; If the interface in-errors value is less than 1000, switch to 60 seconds period value, and then scan all client every 60 seconds up to 360 seconds. 30 seconds and 360 seconds can be seen as time window. The time window lenght is 6 period values. Irrespective of period value set for adaptive subscription, 6 event records during the time window should be generated for the same subscription and send to the receivers.¶
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config>
<target>
<running/>
</target>
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<top xmlns="http://example.com/schema/1.2/config">
<yp:datastore
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
ds:running
</yp:datastore>
<yp:datastore-xpath-filter
xmlns:ex="https://example.com/sample-data/1.0">
/if:ietf-interfaces
</yp:datastore-xpath-filter>
<as:adaptive-subscriptions
xmlns:as="urn:ietf:params:xml:ns:yang:ietf-adaptive-subscription">
<as:data-path>/if:interfaces/if:interface/if:statistics</as:data-path>
<as:target>in-errors</as:target>
<as:adaptive-period>
<as:condition-expression>in-errors < 1000</as:condition-expressioni>
<as:watermark>1000</as:watermark>
<as:period>5</as:period>
<as:count>12</as:count>
</as:adaptive-period>
<as:adaptive-period>
<as:condition-expression>in-errors < 1000</as:condition-expressioni>
<as:watermark>1000</as:watermark>
<as:period>60</as:period>
<as:count>12</as:count>
</as:adaptive-period>
</as:adaptive-subscriptions>
</top>
</config>
</edit-config>
</rpc>¶