Re: [i2rs] Ephemeral State Requirements discussion

[Juergen Schoenwaelder <[e-mail]>]

Sue,

Ephemeral-REQ-03 seems to be in conflict with what YANG validation
rules expects. If I2RS validation depends on 'temporary operational
state', then the validation result is only meaningful at a specific
point in time; YANG validation specially avoids this in order to have
the property that a configuration that is valid remains valid (and
does not become invalid if 'temporary operational state' changes.

Hence: I2RS ephemeral validation != YANG config true validation

/js

On Mon, Jun 06, 2016 at 07:05:15PM -0400, Susan Hares wrote:
> Juergen: 
> 
> Thank you for the pointer,  I am assuming you are referring to section 8.3
> on constraint enforcement (from RFC6020bis), and as a part of constraint
> enforcement, the validation.  
> 
> I2RS ephemeral requirements 1-4 are: 
>    Ephemeral-REQ-01: I2RS requires ephemeral configuration state; i.e. state
> that does not persist
>     across reboots. If state must be restored, it should be done solely
>     by replay actions from the I2RS client via the I2RS agent.
> 
>    Ephemeral-REQ-02: Non-ephemeral state MUST NOT refer to  ephemeral state
> for constraint purposes; 
>    it SHALL be considered a validation error if it does.
>    Ephemeral-REQ-03: Ephemeral state must be able to utilized temporary
> operational state 
>     (e.g. MPLS LSP-ID or a BGP IN-RIB) as a constraints. 
>    Ephemeral-REQ-04: Ephemeral state MAY refer to non-ephemeral state 
>    for purposes of implementing constraints.
> 
> I2RS uses the definition you do of constraint and validation.  For
> discussion purposes, let us consider  "ephemeral state" in these
> requirements as "ephemeral configuration state".   
> 
> What needs to be expanded for Ephemeral Configuration State is the second
> paragraph of section 8.3.3 to include ephemeral state.  In the end, the
> ephemeral configuration parsing of rpc payloads, <edit-config>, and
> validation MUST obey all validation constraints.  What we are discussing is
> "when" and "how" the I2RS constraint enforcement occurs, and "when" and
> "how" validation occurs.   
> 
> Sue 
>   
> 
> ================
> For reference of I2RS list
> 
> 8.3.  NETCONF Constraint Enforcement Model
> 
>    For configuration data, there are three windows when constraints MUST
>    be enforced:
>    o  during parsing of RPC payloads - 
>    o  during processing of the <edit-config> operation
>    o  during validation
>    Each of these scenarios is considered in the following sections.
> 
> 
> 8.3.3.  Validation
> 
>    When datastore processing is complete, the final contents MUST obey
>    all validation constraints.  This validation processing is performed
>    at differing times according to the datastore.  
> 
>   If the datastore is "running" or "startup", these constraints MUST be
> enforced at the end
>    of the <edit-config> or <copy-config> operation.  If the datastore is
>    "candidate", the constraint enforcement is delayed until a <commit>
>    or <validate> operation.
> 
> 
> 
> -----Original Message-----
> From: Juergen Schoenwaelder [mailto:[e-mail]] 
> Sent: Monday, June 06, 2016 4:04 PM
> To: Susan Hares
> Cc: 'Jeffrey Haas'; [e-mail]; 'Joel M. Halpern'
> Subject: Re: [i2rs] Ephemeral State Requirements discussion
> 
> On Mon, Jun 06, 2016 at 03:07:13PM -0400, Susan Hares wrote:
> > Juergen: 
> > 
> > Please start by defining validation for NETCONF configuration.  Then, 
> > we can provide the additions for ephemeral configuration state that 
> > are not in ephemeral requirements.  See the rest of the comments below.
> >
> 
> The validation of NETCONF configurations modelled in YANG 1.0 is defined in
> RFC 6020 and for configurations modelled in YANG 1.1 it is defined in
> draft-ietf-netmod-rfc6020bis-12.
> 
> /js
> 
> PS: Our communication is not effective, I drop out for now.
> 
> -- 
> Juergen Schoenwaelder           Jacobs University Bremen gGmbH
> Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
> Fax:   [phone]         <http://www.jacobs-university.de/>
> 

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