Re: [netmod] comments on revised-datastores-00

[Ladislav Lhotka <[e-mail]>]

Juergen Schoenwaelder <[e-mail]> writes:

> On Mon, Nov 14, 2016 at 11:23:04AM +0900, Ladislav Lhotka wrote:
>> Hi,
>> 
>> I've read the revised-datastores-00 document, in general I like it, here
>> are my initial comments and questions:
>> 
>> 1. Even if <intended> is valid, it can still be in conflict with the
>>    actual content of <applied> that may come from e.g. dynamic
>>    configuration protocols. How are such cases supposed to be resolved?
>
> Yes. The whole idea is to expose these potential differences instead
> of hiding them behind a curtain.

That's fine but it doesn't answer my question.

>
>> 2. What is the distinction between dynamic configuration protocols and
>>    control-plane protocols?
>
> Good question. I believe this to be at the end implementation specific.
> The question I think really is whether a control-plane protocol interacts
> with the configuration management component or not.

OK, perhaps it can be said that dynamic configuration protocols modify
"config true" data. Maybe a term like "configuration interface" may be
better because it needn't be a communication protocol, and it needn't be
any more dynamic than NETCONF/RESTCONF is.

>
>> 3. Shared <candidate> has known problems. Maybe it's time to part with
>>    it in this new datastore model?
>
> This clearly was not the focus of this work.

Then I would suggest to remove it entirely as a protocol-specific thing.

>
>> 4. Templates are briefly mentioned in several places, it would be useful
>>    to explain this concept in more detail.
>
> I agree.
>
>> 5. Is it necessary that "<operational-state> datastore contains all
>>    configuration data actually used by the system"? For example, static
>>    routes should appear in RIBs, so having them separately in operational
>>    state seems redundant.
>
> I do not understand your question. Is the RIB exposed or not? Anyway,
> we need a general model and not a model for specific aspects such as
> routing. Yes, there can be redundancy but there can also be semantic
> differences. The <operational-state> datastore tells me what is
> actually used (regardless of what has happened with the statically
> configured values). In other words, if I want to debug what my box is
> actually doing, looking at the <operational-state> datastore is
> probably a good idea.

But could this part of operational state be possibly different from
what's already in <applied>?

Lada

>
> /js
>
> -- 
> Juergen Schoenwaelder           Jacobs University Bremen gGmbH
> Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
> Fax:   [phone]         <http://www.jacobs-university.de/>

-- 
Ladislav Lhotka, CZ.NIC Labs
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