Subject: [core] pubsub review

From: Peter van der Stok <[email-masked]>
Date: Thu, 24 Jan 2019 19:14:45 +0100

Hi Michael,

The document is progressing nicely but still needs some work.

Below my main comments:

Brokerless pub/sub is very confusing, because there is a broker,
Simply saying in the introduction that the broker is a server that can
be installed on any device, and that the broker can be present on the
same device as a client is more than enough.

I don't understand why the first publication can create a subtopic
without creating the parent and the Create cannot.
Why is there a CREATE anyway? Would be nice if this is motivated.

What about the lifetime of the subscribers. It is non-existent but makes
the lifetime of the subscriber very different over all implementations.
A defaut lifetime would be appreciated.

A table covering the use of POST and PUT for PUBLISH and CREATE with a
short motivation would be welcome.

An update of the resource-discovery text is really needed. You can use
the terms like simple registration and refer to the section numbers.
context is non-existent these days.

Sleep-wake operation.
Nice that you address the sleepy nodes, bur it really deserves more
text. First the context of sleepy node , proxy and client needs
description. Some text is available in Zotti draft.
Followed by a mapping of pubsub functionlity to wanted sleepy-node
functionality.
Also the update of a sleepy node by a client warrants some text. If you
think that this is too much honor for the subject, I suggest to remove
section 6.

Security considerations:
You do not mention the resource exhaustion by creating too many topics.
May I suggest to look at draft-ietf-ace-key-groupcomm-00 and provide 
some concrete links to that draft, possibly with examples?

Some text:
s/receival/reception
3.2 Broker needs to be reachable to its clients (not all)
section 4.3 first paragraph seems to contradict second paragraph (MUST,
MAY)

hope this is relevant,
cheerio,

Peter
-- 
Peter van der Stok
vanderstok consultancy
mailto: [email-masked], [email-masked]
www: www.vanderstok.org [1]
tel NL: +31(0)492474673     F: +33(0)966015248 

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