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Minutes 2016 05 26

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ericvoit edited this page May 26, 2016 · 4 revisions
Meeting Materials Attending
PPT WebEx password: MeDHMCt2 Ambika Prasad Tripathy, Einar Nilsen-Nygaard, Alexander Clemm, Alberto Gonzalez Prieto, Andy Bierman, Sharon Chisholm, Eric Voit, Hector Trevino, Tim Jenkins, Balazs Lengyel, Susan Hares, Walker, Yan Gang, Kent Watsen

Action Items

  • For slides referenced below, see PPT above

  • Looking for a date which is better (E.g., Ebben & Eric have conflicts now)

  • Perhaps Wednesday, same timeslot? Please reply back if you absolutely cannot do Wednesday. (Some people have intermittent conflicts, for example for I2RS interim.)

  • Objective is for next meeting to start reviewing text for the four draft proposals

  • Authors to put text in the Git before next meeting

  • Matched to this text will be list of open issues

  • Hope is to submit this to WG for adoption of all drafts quickly. This request came from WG during interim.

  • Slide 5: Proposal made for Configured Subscriptions and Dynamic

  • No objections to general proposal. Specifics need to be added for diagnostics & troubleshooting

  • Slide 5: What is a Stream

  • Framing streams and identifying which objects go to which stream has a general proposal which seems workable

  • Still need to figure out how to auto-assign things like counters to the right stream types

  • Assignment of objects to streams will be needed for slowly ramping up an increase in subscribable objects on a platform anyway.

    • Not sure we should standardize how to populate streams with this effort. We should just ensure we know how it could be done in an implementation.

  • Slide 6: Difference between Eventing and Periodic with Suppress Redundant behavior

  • Current proposed behavior is that the last change on an object gets pushed at the end of the dampening period

  • There are possible improvements to slide 6 worth discussing.

  • Do we want to wait for a dampening period if a new object changes which hasn't changed previously?

  • Do we want a counter to show the degree of churn during a dampening period.

    • Question: are counters available for counting the changes in leaves with existing models? Answer: No, this is one reason Periodic solutions don't match to use cases where burst dampening is in effect for Routes and Interface state.

  • Periodic solutions only reporting current state can impact applications like traffic engineering as traffic steering cannot take into account flaps underway which are not exposed via current-only state push.

  • Slide 7: Another example of eventing this time with Add/Delete.

  • Proposed behavior is same where you only send the latest change to an object.

  • As this could result in a message showing the deletion of an object with didn't already exist, or the creation of an object which exists, there is a conflict with YANG behavior which doesn't expect dampening. (e.g., RFC 6020: Section 7.6.7. NETCONF Operations)

    • Either we need to make an exception for YANG push dampened streams, or we need another mechanism.

Other useful info

  • I2RS driven YANG Datastore Push Rqts doc through IESG

  • Negotiate vs. auto-adjust - We didn't get to slides 8,9,10

  • These slides provide examples of a service class which is not viable with auto-adjust. The periodic interval and anchor time for synchronization must be established from a central controller.

  • We can talk about this more in the next call as we ran out of time.

  • Current issues being worked

  • Supporting multiple Receivers for a Configured Subscription

  • Proper behavior for on-change, detecting and indicating changes within a Dampening period

  • Negotiate vs. auto-adjust

  • What are the domains of different Stream types.

  • QoS parameters for subscriptions. Relevance for buffering and loss of connectivity (i.e., this isn’t just about HTTP2)

  • Layering security requirements/considerations into the YANG model for Configured Subscription.

  • Mechanisms/RPCs for defined for Diagnostics OpState requirements and implications

  • Deltas for OpenConfig-Telemetry.yang

  • Replay support for different stream types (modify vs. delete)

  • Event Dampening (overwhelming receivers) & rejecting certain subscription types

  • How to structure for non-standardizable encodings

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