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NETCONF Data Modeling Language WG (netmod)
19th YANG 1.1 Virtual Interim
Monday, August 31st, 2015, 17:00-18:00 CEST
Minutes Juergen Schoenwaelder
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* Participants

  DB = Dean Bogdanovic
  JS = Juergen Schoenwaelder
  KW = Kent Watsen
  LL = Ladislav Lhotka
  MB = Martin Bjorklund
  MJ = Mahesh Jethanandani

* Definition of 'data tree'

  One option is to define 'data tree' to capture the choice currently
  embedded in the xpath expression evaluation section. This will make
  the xpath section way simpler. It is unclear whether this also
  brings simplification at other places.
   
  Is it a goal to remove any reference to <running/> in normative
  text? Note that RESTCONF does not have <running/> but instead a
  unified datastore (but it seems this got lately changed again).
   
  Observation: YANG does not define terms like 'datastore' or
  'configuration datastore' or <running/>. RFC 6020 is silently
  assuming the import of these terms from RFC 6241.
   
  MB: I suggest to import the necessary terms.
  JS: I agree that key terms should be defined in the document or
      the definition should be imported. In an ideal world, we would have
      an architecture document defining architectural concepts and then
      YANG and protocol specifications would import from there. We can
      only slowly move to an ideal world in the IETF.

  KW: Should we refer to an 'intended' configuration datastore instead of
      the running configuration datastore?
  LL: Perhaps 'active' configuration with 'active' meaning 'running' on a
      traditional NETCONF server?
   
  KW: running + ephemeral => intended => applied
   
  MB: YANG 1.0 clearly uses running. If we create a new term, it must
      resolve to <running/> in NETCONF.
   
  LL: The issue for me is config false node refering to a config true
      node. With possible future extensions of NETCONF (or RESTCONF),
      referring to <running/> may not be useful anymore.
   
  MB: The notifications in the SMIv2 mapping to YANG make use of
      references to <running/> datastore content.
  JS: But this is accomplished via leafrefs, not via xpath expressions.
   
  Resolution: We keep the choice text in xpath section. We will replace
  <running/> with 'running configuration datastore'.
   
  What about data tree? It seems to make sense to expand its
  definition but we need to figure out where the expansion would not
  be OK. LL volunteers to take a look. MB will do this as well.