My confusion, sorry, I was thinking “mandatory”. Must statements on opstate are useful, but less important.
Kent > On Nov 6, 2023, at 5:26 PM, Kent Watsen <[email protected]> wrote: > > “Must” statements on opstate usefully helps clients know when certain values > will always appear, enabling better optimization and usability. > > E.g., for Syslog messages, there must always be a timestamp, severity, and a > message. It would be unhelpful for the server to not declare its intention > to always send these fields. > > Kent > > >> On Nov 6, 2023, at 10:49 AM, Jason Sterne (Nokia) <[email protected]> >> wrote: >> >> +1 on what Jurgen and Rob are pointing out here. >> >> I'm not sure it makes a ton of sense to actually have a lot of "must" >> statements in state models. We could consider discouraging them? (but we >> need to continue *allowing* them). >> >> Jason >> >>> -----Original Message----- >>> From: netmod <[email protected]> On Behalf Of Rob Wilton >>> (rwilton) >>> Sent: Thursday, November 2, 2023 5:17 AM >>> To: Jürgen Schönwälder <[email protected]>; >>> [email protected] >>> Cc: [email protected] >>> Subject: Re: [netmod] draft-ietf-netmod-rfc8407bis: must + error-message >>> for "config false" >>> >>> >>> CAUTION: This is an external email. Please be very careful when clicking >>> links or opening attachments. See the URL nok.it/ext for additional >>> information. >>> >>> >>> >>> Specifically regarding MUST statements on state date, RFC 8342 section 5.3, >>> also has this statement (which effectively aligns to Jürgen's last >>> paragraph): >>> >>> <operational> SHOULD conform to any constraints specified in the data >>> model, but given the principal aim of returning "in use" values, it >>> is possible that constraints MAY be violated under some circumstances >>> (e.g., an abnormal value is "in use", the structure of a list is >>> being modified, or remnant configuration (see Section 5.3.1) still >>> exists). Note that deviations SHOULD be used when it is known in >>> advance that a device does not fully conform to the <operational> >>> schema. >>> >>> Only semantic constraints MAY be violated. These are the YANG >>> "when", "must", "mandatory", "unique", "min-elements", and >>> "max-elements" statements; and the uniqueness of key values. >>> >>> Syntactic constraints MUST NOT be violated, including hierarchical >>> organization, identifiers, and type-based constraints. If a node in >>> <operational> does not meet the syntactic constraints, then it >>> MUST NOT be returned, and some other mechanism should be used to >>> flag >>> the error. >>> >>> Regards, >>> Rob >>> >>> >>> -----Original Message----- >>> From: netmod <[email protected]> On Behalf Of Jürgen >>> Schönwälder >>> Sent: Wednesday, November 1, 2023 7:46 AM >>> To: [email protected] >>> Cc: [email protected] >>> Subject: Re: [netmod] draft-ietf-netmod-rfc8407bis: must + error-message >>> for "config false" >>> >>> Here is what RFC 7950 says: >>> >>> 7.5.4.1. The "error-message" Statement >>> >>> The "error-message" statement, which is optional, takes a string as >>> an argument. If the constraint evaluates to "false", the string is >>> passed as <error-message> in the <rpc-error> in NETCONF. >>> >>> Since state data is not (directly) modified by processing RPCs, which >>> <rpc-error> would carry the <error-message>? If the answer is 'none', >>> then why define an <error-message> for state data? >>> >>> My take has always been that operational state data should report as >>> much as possible the true state of the device - even if the current >>> state violates certain constraints. The entity to check constraints >>> would be a managing system, not the managed system. That said, the >>> wording in section 7.5.4.1 indicates that the designers had servers >>> processing RPCs in mind. >>> >>> /js >>> >>> On Tue, Oct 31, 2023 at 10:40:15AM +0000, >>> [email protected] wrote: >>>> Hi all, >>>> >>>> In the context of >>>> https://datatracker.ietf.org/doc/draft-ietf-pce-pcep-yang/, >>> Dhruv has received in the past a comment about the use of "must + error- >>> message" for "config false" data nodes. He reported that comment at >>> https://mailarchive.ietf.org/arch/msg/yang- >>> doctors/gWnXnyNHPVv_nZB1PQjThAwP1JY/, but without any follow-up. >>>> >>>> rfc7950#section-8.1 includes a provision for the use of "must" for state >>> data, but silent about the use of error-message. Some guidance for authors >>> may be useful here. >>>> >>>> The following options are being considered: >>>> >>>> (1) Remove both must and error-message for config false data nodes >>>> (2) Remove error-message but keep the must >>>> (3) keep both >>>> >>>> I think that (3) is OK as this is a formal way to detect anomalies in state >>> data, but I'm open to hear what the WG thinks. >>>> >>>> Opinions whether we need to include a mention about this in draft-ietf- >>> netmod-rfc8407bis are welcome. >>>> >>>> Thank you. >>>> >>>> Cheers, >>>> Med >>>> >>>> >>> __________________________________________________________________ >>> __________________________________________ >>>> Ce message et ses pieces jointes peuvent contenir des informations >>> confidentielles ou privilegiees et ne doivent donc >>>> pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu >>> ce message par erreur, veuillez le signaler >>>> a l'expediteur et le detruire ainsi que les pieces jointes. Les messages >>> electroniques etant susceptibles d'alteration, >>>> Orange decline toute responsabilite si ce message a ete altere, deforme ou >>> falsifie. Merci. >>>> >>>> This message and its attachments may contain confidential or privileged >>> information that may be protected by law; >>>> they should not be distributed, used or copied without authorisation. >>>> If you have received this email in error, please notify the sender and >>>> delete >>> this message and its attachments. >>>> As emails may be altered, Orange is not liable for messages that have >>> been modified, changed or falsified. >>>> Thank you. >>> >>>> _______________________________________________ >>>> netmod mailing list >>>> [email protected] >>>> https://www.ietf.org/mailman/listinfo/netmod >>> >>> >>> -- >>> Jürgen Schönwälder Constructor University Bremen gGmbH >>> Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany >>> Fax: +49 421 200 3103 <https://constructor.university/> >>> >>> _______________________________________________ >>> netmod mailing list >>> [email protected] >>> https://www.ietf.org/mailman/listinfo/netmod >>> _______________________________________________ >>> netmod mailing list >>> [email protected] >>> https://www.ietf.org/mailman/listinfo/netmod >> _______________________________________________ >> netmod mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/netmod > > _______________________________________________ > netmod mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/netmod _______________________________________________ netmod mailing list [email protected] https://www.ietf.org/mailman/listinfo/netmod
