[alto] New Incremental Update draft

[Wendy Roome <[e-mail]>]

Folks,

Richard & I updated the incremental update draft:

https://www.ietf.org/internet-drafts/draft-ietf-alto-incr-update-sse-01.txt


The primary change was I added a mechanism to let a client tell the server
to close the stream. This shuts the stream down quickly & cleanly. The
client can just close the stream, of course, but that can take a while for
the server to detect, and it looks like an I/O error.

Section 3 summarizes the other changes, most of which are clarifications.

The Alcatel-Lucent public server,
http://alto.alcatel-lucent.com:8000/directory, provides an Update Stream
resource as described in the -01 draft. The server updates the default
network map every 60 minutes (approximately), and every 5 minutes it
updates a few routingcost values for the default network map and a few
property values.

Note that because that server handles the interop test network, the
updates just replace the current values with the same values. But that
counts as an update in my server, so it exercises all of the update
plumbing.

One wart: when you create a new Update Stream, the initial response is
delayed for 50 seconds. I don't know what causes that delay, but it only
happens on this particular server, and it is very repeatable. That server
is in our corporate DMZ, so it may be a result of the firewall, or
routing, or some other security feature. In any case, once you get over
the initial 50 second delay, subsequent updates arrive quickly.

Oh yes, I could not find an SSE library, so I had to write my own. I would
greatly appreciate it if other people could try it and verify that my SSE
implementation meets the specification.

	- Wendy Roome