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

["Einar Nilsen-Nygaard (einarnn)" <[e-mail]>]

Yes, Option 2 seems best.

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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