Subject: [alto] Shepherd writeup for SSE

From: Vijay Gurbani <[email-masked]>
Date: Mon, 10 Feb 2020 11:52:44 -0600

Folks: The shepherd writeup of SSE is below.  As soon as the authors have
worked the IDNITS bugs, I will move the draft ahead.  In the meantime, if
anything in the shepherd's writeup need changing, please let me know.

Cheers,

- vijay
------
1. Summary

The document shepherd is Vijay K. Gurbani. The responsible Area Director is
Mirja Kuehlewind.

This document allows the base ALTO protocol (RFC 7785) to fetch resources
that
have changed in a more optimized manner.

In base ALTO, a client must periodically re-fetch resources that have
changed.
Some resources served by an ALTO server (network maps, for instance) may be
quite large, while the changes to the resources may be fairly localized,
and can
be served in an optimal manner (sending diffs, for instance) instead of
having
the client fetch the entire updated resource.

This document adds the capability of sending localized diffs in ALTO.

This document is targeted as a Standards Track document (Proposed Standard).
This designation is appropriate as the document contains normative behaviour
and message formats that should be adhered to by the communicating entities
in order to realize the extension.

2. Review and Consensus

ALTO incremental updates is a well known work to the ALTO working group.
The
initial work on this started in October 2014; the working group adopted the
work
in May 2015 [1], after which it has gone through about 19 revisions to the
current
version.  The work is fairly mature and the design tradeoffs in coming up
with an
equitable solution to the problem described above are well documented in the
draft.

The first WGLC on version -02 of the draft was held on Jul-2016 [2] and was
reviewed by Mingming Chen and Sebastial Kiesel.  However, it was pointed out
[3] after the WGLC ended that the draft could be made far more general if it
supported additional incremental update encoding options.  The draft,
therefore,
continued its journey within the WG instead of being sent out to the IESG.
At
IETF 99, a hum was taken on whether we should proceed to WGLC on version -07
[4], but the hum did not reach any hard conclusion and the work proceeded
in the
WG.

In an interim ALTO meeting held on Dec-18-2017, the authors indicated that
they
were still working on the draft [5].  A second WGLC was held on Jun-20-2018
[6],
and was reviewed by three WG members (Dawn Chan, Kerim Gokarslan and
Isabelle
Carson).  Pursuant to the WGLC, version -11 was released with updates,
shortly
followed by version -13.  It was determined that version -13 had some
substantive changes in it that it may help in further review from the WG
[7].
Between 2018 and the issuance of a third WGLC on Nov-14-2019 [8], work
progressed on the document.  The third WGLC resulted in review of the work
by
Jensen Zhang and me.

There is one known implementation of this draft, this implementation is
related
to a paper titled "Steering Hyper-Giant's Traffic at Scale",  published in
the
proceedings of ACM CoNEXT 2019 [9].  This implementation implements the JSON
merge patch feature, with the general JSON patch being on their roadmap
[10].

[1] https://mailarchive.ietf.org/arch/msg/alto/1nLabIj25PJz3M0SOuXAAdLlSBs
[2] https://mailarchive.ietf.org/arch/msg/alto/mnuzhFkDTBDTuRMSDIV2GKXk96A
[3] https://mailarchive.ietf.org/arch/msg/alto/XgvZXhr0PsqAU8CGfEwel1ClIBM
[4] https://mailarchive.ietf.org/arch/msg/alto/t_xHbbGE2g51LqI8cfnyIkwt0J4
[5]
https://datatracker.ietf.org/meeting/interim-2017-alto-01/materials/minutes-interim-2017-alto-01-201712180600/
[6] https://mailarchive.ietf.org/arch/msg/alto/NNrG6P7MjRW1GwYbIJFUDi1089k
[7] https://mailarchive.ietf.org/arch/msg/alto/T8NOGMtb_kRrxJtsE0ToosR-JC4
[8] https://mailarchive.ietf.org/arch/msg/alto/hHM_bC1CfwygcxTTm96zBbj7gmo
[9] https://mailarchive.ietf.org/arch/msg/alto/h7QJRu47NbTvfcnW2fveFqCBRdw
[10] https://mailarchive.ietf.org/arch/msg/alto/9IOwXNAxqKp_CwKUPsu54W4lB08

3. Intellectual Property

The entire author team has confirmed conformance with BCP 78/79 with the
shepherd.

4. Other Points
IDNITS reports problems.  Sending these to the author team.  Waiting an
updated
version.