Essay style shepherd writeup for draft-ietf-alto-incr-update-sse-19
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 on -18: references were not divided into normative and
informative sections. Authors have corrected this in -19 version.