[core] pubsub review

Peter van der Stok <stokcons@bbhmail.nl> Thu, 24 January 2019 18:14 UTC

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Date: Thu, 24 Jan 2019 19:14:45 +0100
From: Peter van der Stok <stokcons@bbhmail.nl>
To: Core <core@ietf.org>
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Subject: [core] pubsub review
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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
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:
3.2 Broker needs to be reachable to its clients (not all)
section 4.3 first paragraph seems to contradict second paragraph (MUST,

hope this is relevant,

Peter van der Stok
vanderstok consultancy
mailto: consultancy@vanderstok.org, stokcons@bbhmail.nl
www: www.vanderstok.org [1]
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