[i2rs] comments on draft-ietf-i2rs-ephemeral-state-10

[Juergen Schoenwaelder <[e-mail]>]

Hi,

here are few comments on the latest version.

   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.

I am not sure what 'must be able to utilized temporary operational
state as constraints' means. The text in the parenthesis does not help
me understand this better. Did you want to say something like:
'Ephemeral configuration state may have constraints that refer to
operational state'? I am using 'ephemeral configuration state' since
this is used in other places (although sometimes worded slightly
different).

   Ephemeral-REQ-04: Ephemeral state MAY refer to non-ephemeral state
   for purposes of implementing constraints.

Hm, now I wonder whether this is just a special case of
Ephemeral-REQ-03 and if so it is not clear why we need this as a
separate requirement. If this is not the case but something different,
then likely my interpretation of Ephemeral-REQ-03 is wrong.

s/2RS/I2RS in Ephemeral-REQ-05. I would actually rewrite the beginning
of Ephemeral-REQ-05 as follows:

   Ephemeral-REQ-05: I2RS interactions may
   lead to undesirable or unsustainable resource consumption on a system
   implementing an I2RS Agent.  It is RECOMMENDED that mechanisms be
   made available to permit prioritization of I2RS interactions, when
   appropriate, to permit implementations to shed work load when
   operating under constrained resources.  An example of such a work
   shedding mechanism is rate-limiting.

I would remove the Note: since I believe the key observation here are
the potentially high volume of I2RS interactions and not the fact that
there is a datastore involved that is ephemeral.

I am still struggling with Ephemeral-REQ-06:

   Ephemeral-REQ-06: The ability to augment an object with appropriate
   YANG structures that have the property of being ephemeral.  An object
   defined as any one of the following: yang module, submodule or
   components of submodule, or schema node.

Perhaps this is what you wanted to say?

   Ephemeral-REQ-06: The ability to augment YANG schema nodes with
   additional YANG schema nodes that have the property of being
   ephemeral.

I wonder why there are some ephemeral state requirements in sections
labeled with "I2RS Protocol version 1" while others seem to be
protocol version agnostic. What is the definition of I2RS protocol
versions?  Perhaps this notion of protocol version should simply be
removed; I am not sure it helps with the requirements.

   Ephemeral-REQ-08: Yang MUST have a way to indicate in a data model
   that nodes have the following properties: ephemeral, writable/not-
   writable, and status/configuration.

This is confusing because it says 'nodes' while in YANG we distinguish
data nodes and schema nodes. For example, in YANG a schema node has a
property config true|false. This schema node property defines whether
corresponding data nodes are writable/non-writable. In other words,
some of this requirement seems to be covered by YANG already; so what
remains is the 'ephemeral' property - does the requirement expect this
to be a property of a schema node?

Editorial: s/prevent was the oscillation/prevent oscillation/

/js

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