Thx for the quick thoughts Rob.

I2RS has defined that a 'set' would fail within the dynamic DS but they didn't 
really consider/specify that a 'set' to the dynamic DS could actually fail due 
to the existence of something in the conventional DSes.  I suppose a custom DS 
(like the i2rs ephemeral) can in theory define whatever behavior they want but 
it may be odd that something written to the dynamic DS fails when there isn't 
something higher prio in the dynamic DS itself.

But someone can sort that out if they ever propose a model that is supported 
both in a dynamic DS and in a conventional DS (assuming we don't want to 
propose guidelines for that behavior in the revised DS draft).

Rgds,
Jason

From: Robert Wilton [mailto:[email protected]]
Sent: Tuesday, July 18, 2017 23:11
To: Sterne, Jason (Nokia - CA/Ottawa) <[email protected]>; [email protected]
Subject: Re: [netmod] revised-datastores-03: duplicate list entry from 
conventional + dynamic


Hi Jason,

Some thoughts inline ...

On 18/07/2017 22:46, Sterne, Jason (Nokia - CA/Ottawa) wrote:
Hi all,

The discussions about dynamic datastores in I2RS today made me wonder about a 
scenario:  What if a data model is supported in both conventional datastores 
and in a dynamic datastore (as well as being readable from the operational 
datastore), and the same list entry (e.g. interface abc, but with some 
different parms in the dynamic entry vs the config entry) has been created in 
both the running and the dynamic DS.

Only one of them can appear when reading the operational DS.
Yes.



I presume that it is up to the specification document of the dynamic DS to 
define the collision resolution between dynamic & conventional.
Yes.



But based on the revised DS draft I believe it would be necessary for the 
system to keep/store both copies of 'interface abc' so that a <get-data> with 
source=dynamic would return the dynamic version of interface abc while a 
<get-config> (or <get-data>) with source=running would return the conventional 
version of interface abc.  Do I have that correct ?
Definitely yes for running.  For dynamic, it would depend on the definition of 
the specific dynamic datastore, but likely yes.



I think that also implies that removing one of the copies could cause the 
're-installation' of the other (down to the app layer).
This would also depend on the definition of the specific dynamic datastore.

Most likely, if the dynamic entry is removed, then the conventional configured 
value should be re-instated.  However, I don't think that the reverse is 
necessarily true.  E.g. in the dynamic datastore is I2RS then the initial 
config event would have failed if it was lower priority that conventional.



This concept of storing multiple copies and re-installation is something I2RS 
wants to avoid.
This is perhaps more related to multiple I2RS clients rather than between I2RS 
and the conventional datastores.


  But since they have declared that their scope only includes the use of their 
models in the dynamic (ephemeral) DS, they won't have that behavior.

Rgds,
Jason

Thanks,
Rob






_______________________________________________

netmod mailing list

[email protected]<mailto:[email protected]>

https://www.ietf.org/mailman/listinfo/netmod

_______________________________________________
netmod mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/netmod

Reply via email to