Technical Summary
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.
Working Group Summary
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.
Document Quality
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].
Personnel
The document shepherd is Vijay K. Gurbani. The responsible Area Director is
Mirja Kühlewind.