]> Telemetry Data Export capability Huawei
101 Software Avenue, Yuhua District Nanjing Jiangsu 210012 China bill.wu@huawei.com
Huawei
101 Software Avenue, Yuhua District Nanjing Jiangsu 210012 China maqiufang1@huawei.com
China Mobile
32 Xuanwumen West St, Xicheng District Beijing 10053 gengliang@chinamobile.com
China Mobile
32 Xuanwumen West St, Xicheng District Beijing 10053 liupengyjy@chinamobile.com
OPS Area NETCONF Working Group 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.
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: A set of capabilities related to the amount of notifications the server can send out Specification of which data nodes support on-change notifications. 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. 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 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: Specification of transport protocol the client can use to establish transport connection; Specification of encoding selection(e.g., XML or JSON, to binary) of Data Modeled with YANG; Specification of secure transport mechanisms that are needed by the client to communicate with the server; Specification of the type of data compression algorithm (e.g., lossless data compression) the client can use for file compression and decompression Specification of the notification message encapsulation type, either one notification per message or multiple notifications per message. Specification of the update trigger type such as adaptive interval trigger, timer event based trigger, count threshold trigger, redundant suppression.
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: /sysc:system-capabilities/dec:transport-protocol /sysc:system-capabilities/dec:encoding-format /sysc:system-capabilities/dec:secure-transport /sysc:system-capabilities/dec:compression-mode /sysc:system-capabilities/inc:subscription-capabilities/dec:message-bundling-support /sysc:system-capabilities/inc:subscription-capabilities/dec:subscription-mode /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-node-capabilities/dec:sampling-interval
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>
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>