Re: [netmod] AD review of draft-ietf-netmod-entity-06

[Joe Clarke <[e-mail]>]

On 1/12/18 05:52, Einar Nilsen-Nygaard (einarnn) wrote:
> Yes, Option 2 seems best.

Agreed.  I believe most assume these are static values from the vendor
that are not field-writeable (certainly that is true from what I've seen
here at Cisco).

Joe

> 
> Cheers,
> 
> Einar
> 
> 
>> On 11 Jan 2018, at 17:56, Robert Wilton -X (rwilton - ENSOFT LIMITED at Cisco) <[e-mail]> wrote:
>>
>>
>>
>> On 11/01/2018 13:47, Martin Bjorklund wrote:
>>> Hi,
>>>
>>> To summarize this, I think we have three options for the three nodes
>>> 'model-name', 'mfg-name', and 'serial-num':
>>>
>>>   1.  Do nothing (keep the nodes as config true).
>>>
>>>   2.  Make these three nodes config false (fairly simple change).
>>>       (vendors can augment w/ their own config true nodes).
>>>
>>>   3.  Add three new nodes for the configured values.
>>>
>>>
>>> After thinking about this some more, and discussing with Benoit, I
>>> think the best path forward is to do 2, i.e., mark the nodes
>>> 'model-name', 'mfg-name', and 'serial-num' as "config false".  As such
>>> they would not be configurable, and thus contain the detected values.
>>> If no value is detected, the node is not present.
>> Option 2 suits me.  It keeps it simple.
>>
>>>
>>> Note that 1 or 3 can be done in a future update to this module (or by
>>> a vendor).
>> Agreed.
>>
>> Thanks,
>> Rob
>>
>>
>>>
>>>
>>> /martin
>>>
>>>
>>> Martin Bjorklund <[e-mail]> wrote:
>>>> Hi,
>>>>
>>>> "Bogaert, Bart (Nokia - BE/Antwerp)" <[e-mail]> wrote:
>>>>> Hi,
>>>>>
>>>>> --- snip ---
>>>>>
>>>>>> state.”, so the above sentence only applies for the second case below.
>>>>> Ok.
>>>>>
>>>>>> 2. The second case is that something is detected but it can’t be read.
>>>>>> We do not see a reason to use the value configured for the leafs
>>>>>> ‘serial-num’, ‘mfg-name’ and ‘model-name’ of a matching entry in the
>>>>>> configuration data.  These leafs are defined as optional so why would
>>>>>> we report something entered by an operator in the operational
>>>>>> datastore that intends to report on what is detected?  Is it not
>>>>>> better to not report them at all?  In an NMDA context it would be
>>>>>> possible to have a different value (or no value at all) for certain
>>>>>> leafs while there is something in the running/intended datastore.
>>>>> The normal NMDA procedure for a configuration leaf is to repeat it in
>>>>> operational state.  This is then the "applied configuration".
>>>>> I don't think we should have a special rule for these leafs.
>>>>>
>>>>> This also means that a client that just wants to read all the serial
>>>>> numbers can do so from one place, the operational state, regardless of
>>>>> how they came into existance.
>>>>>
>>>>> [Bogaert, Bart ]
>>>>>
>>>>> We do understand that a target of NMDA is to read out the actually
>>>>> applied data in one request.  But the result should not be
>>>>> confusion. A key word is “applied”.
>>>>>
>>>>> Section 5.3 of draft-ietf-netmod-revised-datastores-09 also contains
>>>>> (I put a part of the section between ***):
>>>>> The datastore schema for <operational> MUST be a superset of the
>>>>> combined datastore schema used in all configuration datastores except
>>>>> that configuration data nodes supported in a configuration datastore
>>>>> ***MAY be omitted from <operational> if a server is not able to
>>>>> accurately report them ***.
>>>> Note that this text talks about the *schema*.  It is intended for
>>>> servers to migrate to NMDA without having to instrument all config
>>>> nodes in <operational> immediately.  If you apply this to
>>>> ietf-hardware, it could be a server that implements the node
>>>> "serial-num" in config, but not in <operational> (which would be
>>>> weird).
>>>>
>>>>> For example, it is expected that the value of multiple leafs need to
>>>>> be a consistent set, e.g. the mfg-name, the model-name, and the
>>>>> serial-num.
>>>>> Suppose we have a use case in which a hardware component is
>>>>> planned/configured (e.g. a board supporting DSL interfaces) but a
>>>>> different one is plugged (e.g. a board supporting ethernet
>>>>> interfaces).
>>>>> Suppose it is possible to read some fields on the detected component
>>>>> but due to an issue not to read other fields.
>>>>> If in that case the operational datastore will be completed with the
>>>>> data taken from the running datastore, then the presented view might
>>>>> be inconsistent.
>>>> This is true for other similar nodes as well - "asset-id" and "uri".
>>>>
>>>>> The question is also: what data is applied? Our assumption: if there
>>>>> is a mismatch between detected versus configured hardware, then the
>>>>> interface/service related data that is configured consistently with
>>>>> the planned hardware is not applied on the mismatching
>>>>> hardware. I.e. the detected hardware is not brought in service so not
>>>>> ‘applied’, the operational datastore only (accurately) reports on what
>>>>> is detected.
>>>> If there is a mismatch and the server doesn't apply the configured
>>>> values, then obviously the configured 'mfg-name' etc are not copied to
>>>> <operational>.
>>>>
>>>>> We do not see this as a special rule for this data but rather would
>>>>> apply a general rule:
>>>>> -	if there is a ‘missing resource’, then the data is not reported in the
>>>>>  	operational datastore.
>>>>> -	If the server is not able to report accurately, then the data is
>>>>>  	omitted from the operational
>>>> I think that if you want complete separation between the values of
>>>> 'mfg-name', 'model-name', and 'serial-num' in configuration and
>>>> operational state, then these should be modelled as separate leafs.
>>>> We should have a config false leaf 'serial-num' that only contains the
>>>> detected value (if found), and a config true leaf 'config-serial-num'
>>>> or something, that contains the configured serial number.
>>>>
>>>> But if this is the case, I wonder if it wouldn't be better to leave
>>>> such additional config objects to vendors, and simply make these three
>>>> nodes config false in ietf-hardware.
>>>>
>>>>
>>>> /martin
>>>>
>>>>> Regards, Bart
>>>>>
>>>>> /martin
>>>>>
>>>>>
>>>>>> Best regards, Bart
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: netmod [mailto:[e-mail]] On Behalf Of Robert
>>>>>> Wilton
>>>>>> Sent: Thursday, December 21, 2017 4:14 PM
>>>>>> To: Martin Bjorklund <[e-mail]>; [e-mail]
>>>>>> Subject: Re: [netmod] AD review of draft-ietf-netmod-entity-06
>>>>>>
>>>>>> Hi Martin,
>>>>>>
>>>>>>
>>>>>> On 21/12/2017 11:37, Martin Bjorklund wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> I need WG input on this issue.  The question is how to handle
>>>>>>> 'serial-num', 'mfg-name', and 'model-name'.  I think they should all
>>>>>>> be treated the same.  Based on previous WG discussion (see e.g. the
>>>>>>> mail thread "draft-ietf-netmod-entity issue #13"), I think they
>>>>>>> should all be configurable, but the configured value is only used in
>>>>>>> operational state if the system cannot read it from the hardware.
>>>>>> I think that this approach is probably OK:
>>>>>>   - The client can always see the real value if it is available.
>>>>>>   - If it is not available then they can assign a value via
>>>>>> configuration.
>>>>>>
>>>>>> I was also considering an alternative approach of having a separate
>>>>>> set of config false leaves for the "burnt in values".  And then having
>>>>>> the configurable leaves always override the default operational
>>>>>> values. E.g. similar to how an interface MAC address would expect to
>>>>>> be handled.
>>>>>>
>>>>>> But one set of leaves is probably sufficient.
>>>>>>
>>>>>> Thanks,
>>>>>> Rob
>>>>>>
>>>>>>
>>>>>>> So I suggest the following changes:
>>>>>>>
>>>>>>> OLD:
>>>>>>>
>>>>>>>        leaf serial-num {
>>>>>>>          type string;
>>>>>>>          config false;
>>>>>>>          description
>>>>>>>            "The vendor-specific serial number string for the
>>>>>>>             component.  The preferred value is the serial number
>>>>>>>             string actually printed on the component itself (if
>>>>>>>             present).";
>>>>>>>          reference "RFC 6933: entPhysicalSerialNum";
>>>>>>>        }
>>>>>>>
>>>>>>> NEW:
>>>>>>>
>>>>>>>        leaf serial-num {
>>>>>>>          type string;
>>>>>>>          description
>>>>>>>            "The vendor-specific serial number string for the
>>>>>>>             component.  The preferred value is the serial number
>>>>>>>             string actually printed on the component itself (if
>>>>>>>             present).
>>>>>>>
>>>>>>>             This leaf can be configured.  There are two use cases for
>>>>>>>             this; as a 'post-it' note if the server cannot determine
>>>>>>>             this value from the component, or when pre-provisioning a
>>>>>>>             component.
>>>>>>>
>>>>>>>             If the server can determine the serial number from the
>>>>>>>             component, then that value is always used in operational
>>>>>>>             state, even if another value has been configured.";
>>>>>>>          reference "RFC 6933: entPhysicalSerialNum";
>>>>>>>        }
>>>>>>>
>>>>>>> And corresponding text for 'mfg-name' and 'model-name'.
>>>>>>>
>>>>>>> And also:
>>>>>>>
>>>>>>> OLD:
>>>>>>>
>>>>>>>           When the server detects a new hardware component, it
>>>>>>>           initializes a list entry in the operational state.
>>>>>>>
>>>>>>>           If the server does not support configuration of hardware
>>>>>>>           components, list entries in the operational state are
>>>>>>>           initialized with values for all nodes as detected by the
>>>>>>>           implementation.
>>>>>>>
>>>>>>>           Otherwise, the following procedure is followed:
>>>>>>>
>>>>>>>             1. If there is an entry in the /hardware/component list in
>>>>>>>                the intended configuration with values for the nodes
>>>>>>>                'class', 'parent', 'parent-rel-pos' that are equal to
>>>>>>>                the detected values, then:
>>>>>>>
>>>>>>>             1a. If the configured entry has a value for 'mfg-name'
>>>>>>>                 that is equal to the detected value, or if the
>>>>>>>                 'mfg-name' value cannot be detected, then the list
>>>>>>>                 entry in the operational state is initialized with the
>>>>>>>                 configured values for all configured nodes, including
>>>>>>>                 the 'name'.
>>>>>>>
>>>>>>>                 Otherwise, the list entry in the operational state is
>>>>>>>                 initialized with values for all nodes as detected by
>>>>>>>                 the implementation.  The implementation may raise an
>>>>>>>                 alarm that informs about the 'mfg-name' mismatch
>>>>>>>                 condition.  How this is done is outside the scope of
>>>>>>>                 this document.
>>>>>>>
>>>>>>>             1b. Otherwise (i.e., there is no matching configuration
>>>>>>>                 entry), the list entry in the operational state is
>>>>>>>                 initialized with values for all nodes as detected by
>>>>>>>                 the implementation.
>>>>>>>
>>>>>>>           If the /hardware/component list in the intended
>>>>>>>           configuration is modified, then the system MUST behave as if
>>>>>>>           it re-initializes itself, and follow the procedure in
>>>>>>> (1).";
>>>>>>>
>>>>>>> NEW:
>>>>>>>
>>>>>>>           When the server detects a new hardware component, it
>>>>>>>           initializes a list entry in the operational state.
>>>>>>>
>>>>>>>           If the server does not support configuration of hardware
>>>>>>>           components, list entries in the operational state are
>>>>>>>           initialized with values for all nodes as detected by the
>>>>>>>           implementation.
>>>>>>>
>>>>>>>           Otherwise, the following procedure is followed:
>>>>>>>
>>>>>>>             1. If there is an entry in the /hardware/component list in
>>>>>>>                the intended configuration with values for the nodes
>>>>>>>                'class', 'parent', 'parent-rel-pos' that are equal to
>>>>>>>                the detected values, then the list entry in operational
>>>>>>>                state is initialized with the configured values,
>>>>>>>                including the 'name'.  The leafs 'serial-num',
>>>>>>>                'mfg-name', and 'model-name' are treated specially; see
>>>>>>>                their descriptions for details.
>>>>>>>
>>>>>>>             2. Otherwise (i.e., there is no matching configuration
>>>>>>>                entry), the list entry in the operational state is
>>>>>>>                initialized with values for all nodes as detected by
>>>>>>>                the implementation.
>>>>>>>
>>>>>>>           If the /hardware/component list in the intended
>>>>>>>           configuration is modified, then the system MUST behave as if
>>>>>>>           it re-initializes itself, and follow the procedure in
>>>>>>> (1).";
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> /martin
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Benoit Claise <[e-mail]> wrote:
>>>>>>>> On 12/20/2017 4:00 PM, Martin Bjorklund wrote:
>>>>>>>>> Benoit Claise <[e-mail]> wrote:
>>>>>>>>>> Hi Martin,
>>>>>>>>>>
>>>>>>>>>> Thanks.
>>>>>>>>>> Only kept the relevant excerpts.
>>>>>>>>>>>> - Some objects are read-write in RFC6933:
>>>>>>>>>>>>          entPhysicalSerialNum
>>>>>>>>>>>>          entPhysicalAlias
>>>>>>>>>>>>          entPhysicalAssetID
>>>>>>>>>>>>          entPhysicalUris
>>>>>>>>>>>>
>>>>>>>>>>>> For example, entPhysicalSerialNum being read-write always bothered
>>>>>>>>>>>> me.
>>>>>>>>>>>> serial-num is now "config false", which is a good news IMO.
>>>>>>>>>>> Actually, this was not the intention.  In
>>>>>>>>>>> draft-ietf-netmod-entity-03 this is configurable.  I missed this
>>>>>>>>>>> in the conversion to NMDA.
>>>>>>>>>> Ah. So no good news in this case...
>>>>>>>>>>>> In the reverse direction, entPhysicalMfgName is read-only in
>>>>>>>>>>>> RFC6933, while it's "config true" in draft-ietf-netmod-entity
>>>>>>>>>>> Yes, this was added per request from the WG.  See e.g. the
>>>>>>>>>>> thread "draft-ietf-netmod-entity issue #13".
>>>>>>>>>> Sure. It was mainly an observation.
>>>>>>>>>>> However, I think that what we have now is probably not correct.
>>>>>>>>>>> I think that all nodes 'serial-num', 'mfg-name', and 'model-name'
>>>>>>>>>>> should be config true, and the description of list 'component'
>>>>>>>>>>> updated to reflect that all these tree leafs are handled the same way.
>>>>>>>>>>>
>>>>>>>>>>> I would like to know what the WG thinks about this.
>>>>>>>>>> Talking as a contributor this time.
>>>>>>>>>> It seems that inventory management is kind of broken when someone
>>>>>>>>>> can change 'serial-num', 'mfg-name', and 'model-name.
>>>>>>>>> They can't really change them.  The configured values are only
>>>>>>>>> used (i.e. visible in the operational state) if the device cannot
>>>>>>>>> detect them automatically.  I.e., they work as "post-it" notes only.
>>>>>>>> If I look at, for example, the mfg-name, description, this is not
>>>>>>>> what it says.
>>>>>>>>
>>>>>>>>     leaf mfg-name {
>>>>>>>>             type string;
>>>>>>>>             description
>>>>>>>>               "The name of the manufacturer of this physical component.
>>>>>>>>                The preferred value is the manufacturer name string
>>>>>>>>                actually printed on the component itself (if present).
>>>>>>>>
>>>>>>>>                Note that comparisons between instances of the model-name,
>>>>>>>>                firmware-rev, software-rev, and the serial-num nodes are
>>>>>>>>                only meaningful amongst component with the same value of
>>>>>>>>                mfg-name.
>>>>>>>>
>>>>>>>>                If the manufacturer name string associated with the
>>>>>>>>                physical component is unknown to the server, then this
>>>>>>>>                node is not instantiated.";
>>>>>>>>             reference "RFC 6933 <https://tools.ietf.org/html/rfc6933>:
>>>>>>>>             entPhysicalMfgName";
>>>>>>>>
>>>>>>>> Regards, Benoit
>>>>>>>>
>>>>>>>>> /martin
>>>>>>>>> .
>>>>>>>>>
>>>>>>> _______________________________________________
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>>>>>>> https://www.ietf.org/mailman/listinfo/netmod
>>>>>>> .
>>>>>>>
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