NETCONF Working Group Q. Wu Internet-Draft B. Wu Intended status: Standards Track Huawei Expires: January 9, 2021 P. Liu H. Cai China Mobile July 8, 2020 Self-explanation data Node tag capability draft-tao-netconf-notif-node-tag-capabilities-02 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-explanation data Node tag capability which augments system capabilities model and provide additional self-explanation 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 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 January 9, 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. Wu, et al. Expires January 9, 2021 [Page 1] Internet-Draft Node Tags Capability July 2020 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 . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 4.1. Updates to the IETF XML Registry . . . . . . . . . . . . 8 4.2. Updates to the YANG Module Names Registry . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 9 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 7.1. Normative References . . . . . . . . . . . . . . . . . . 10 7.2. Informative References . . . . . . . . . . . . . . . . . 11 Appendix A. Targeted data object subscription example . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 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 Wu, et al. Expires January 9, 2021 [Page 2] Internet-Draft Node Tags Capability July 2020 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-explanation data Node tag capability which augments System Capabilities model and provide additional self-explanation 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. Wu, et al. Expires January 9, 2021 [Page 3] Internet-Draft Node Tags Capability July 2020 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 object type nodes, which performance metric nodes, which property related nodes they can push to the target recipient; o Specification of measurement precision or granularity associated with performance metric related data nodes; o Specification of operation type associated with performance metric related data nodes; o Specification of service classification information associated with data nodes; o Specification of task group information associated with a set of data nodes; o Specification of self tag name of a set of data nodes they can push to the target recipient. o Specification of data source type associated with a set of data nodes; o Specfication of multi-source aggregation assocaited with a set of data nodes; 2.1. Tree Diagram The following tree diagram [RFC8340] provides an overview of the data model. Wu, et al. Expires January 9, 2021 [Page 4] Internet-Draft Node Tags Capability July 2020 module: ietf-self-explanation-capabilities augment /sysc:system-capabilities/sysc:datastore-capabilities/ + sysc:per-node-capabilities/sys:node-selection/sys:node-selector: +--ro self-describing-attributes* [self-tag-id] +--ro self-tag-id string +--ro opm-tag tags:tag +--ro metric-precision tags:tag +--ro metric-scale tags:tag +--ro operation-type tags:tag +--ro service-tag* tags:tag +--ro task-tag* tags:tag +--ro data-source tags:tag +--ro muli-source-tag tags:tag 3. YANG Module file "ietf-self-explanation-capabilities.yang" module ietf-self-explanation-capabilities { yang-version 1.1; namespace urn:ietf:params:xml:ns:yang:ietf-self-explanation-capabilities; prefix sec; import ietf-system-capabilities { prefix sysc ; } import ietf-module-tags { prefix tags; } organization "IETF NETMOD (Network Modeling) Working Group"; contact "WG Web: WG List: Editor: Qin Wu Bo Wu Wu, et al. Expires January 9, 2021 [Page 7] Internet-Draft Node Tags Capability July 2020 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-explanation-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-explanation-capabilities namespace: urn:ietf:params:xml:ns:yang:ietf-self-explanation-capabilities prefix: sec reference: RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove this note.) 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 Wu, et al. Expires January 9, 2021 [Page 8] Internet-Draft Node Tags Capability July 2020 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:self-tag-id 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-precision o /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per- node-capabilities/sys:node-selection/sys:node-selector/sec:self- describing-attributes/sec:operation-type o /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per- node-capabilities/sys:node-selection/sys:node-selector/sec:self- describing-attributes/sec:service-tag o /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per- node-capabilities/sys:node-selection/sys:node-selector/sec:self- describing-attributes/sec:task-tag o /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per- node-capabilities/sys:node-selection/sys:node-selector/sec:self- describing-attributes/sec:data-source 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 for his major contributions to the initial modeling and use cases. 7. References Wu, et al. Expires January 9, 2021 [Page 9] Internet-Draft Node Tags Capability July 2020 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, . [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [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, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [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, . [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018, . Wu, et al. Expires January 9, 2021 [Page 10] Internet-Draft Node Tags Capability July 2020 [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . 7.2. Informative References [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . 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. Wu, et al. Expires January 9, 2021 [Page 11] Internet-Draft Node Tags Capability July 2020 +-----------+ +-----------+ | 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) | | <--------------------------------| | | | | | | 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: Wu, et al. Expires January 9, 2021 [Page 12] Internet-Draft Node Tags Capability July 2020 acme-router-notification-capabilities ietf-system-capabilities@2020-03-23 ietf-notification-capabilities@2020-03-23 ietf-data-export-capabilities@2020-03-23 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. ds:operational \ /if:interfaces/if:interface/if:statistics/if:in-errors\ bandwith metric 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. Wu, et al. Expires January 9, 2021 [Page 13] Internet-Draft Node Tags Capability July 2020 ds:operational /if:interfaces/if:interface/if:statistics/if:in-errors 500 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 Bo Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: lana.wubo@huawei.com Peng Liu China Mobile 32 Xuanwumen West St, Xicheng District Beijing 10053 Email: liupengyjy@chinamobile.com Wu, et al. Expires January 9, 2021 [Page 14] Internet-Draft Node Tags Capability July 2020 Hui Cai China Mobile 32 Xuanwumen West St, Xicheng District Beijing 10053 Email: caihui@chinamobile.com Wu, et al. Expires January 9, 2021 [Page 15]