RFC 8639, "Subscription to YANG Notifications", September 2019

Errata ID: 8427
Status: Held for Document Update
Type: Technical
Publication Format(s) : TEXT
Reported By: Alex Huang Feng
Date Reported: 2025-05-22
Held for Document Update by: Mahesh Jethanandani
Date Held: 2025-07-29

Section 4 says:

    uses subscription-policy-modifiable {
      augment "target/stream" {
        description
          "Adds additional objects that can be modified by an RPC.";
        leaf stream {
          type stream-ref {
            require-instance false;
          }
          mandatory true;
          description
            "Indicates the event stream to be considered for
             this subscription.";
        }

It should say:

    uses subscription-policy-modifiable {
      augment "target/stream" {
        description
          "Adds additional objects that can be modified by an RPC.";
        leaf stream {
          when "/sn:streams/sn:stream";
          type stream-ref {
            require-instance false;
          }
          mandatory true;
          description
            "Indicates the event stream to be considered for
             this subscription.";
        }

Notes:

The mandatory leaf "stream" is an augmentation on "target/stream".

Section 7.17 of RFC7950 states that any augmentation of mandatory leaves need a "when" statement:
If the augmentation adds mandatory nodes (see Section 3) that
represent configuration to a target node in another module, the
augmentation MUST be made conditional with a "when" statement. Care
must be taken when defining the "when" expression so that clients
that do not know about the augmenting module do not break.

Or else, the "mandatory" statement needs to be removed.

No objections received from the WG to mark it for "Held for Document Update". In addition Andy wrote:

"I am not sure this augment-when rule from RFC 7950 really applies here.
The augmenting leaf is in the same module, and all the objects were produced as a first release.
The added when-stmt is needed if the mandatory node is added in a new release of the same module
or if it is defined in a separate module.

IMO this should be held for document update for clarification."

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