Initial review of INFOD specification

[Matthew I Roberts <matt.roberts@uk.ibm.com>]

All,

Please find attached a copy of the INFOD
specification that I volunteered to take a look at on last week's WSN call.
I have included some comments in the document that highlight my thoughts/concerns
etc.

I must qualify my review with two caveats
- firstly I was pressed for time (so I apologize if I have missed things
I would normally have picked up) and secondly I'm not sure I was able to
give my efforts sufficient time to get a full and detailed view of what
the specification is trying to achieve. This may mean that I have misinterpretted
things and lead my comments down a blind alley.

As far as I can tell, INFOD is a specification
which is aimed at providing a mechanism for creating the association between
a producer of events, and a consumer in some way which can be more advanced
than the standard WSN pattern. In particular there is a INFO Registry service
to which all producers and consumers register, and in which an INFOD subscription
is created (different to a WSN subscription) which indicates that types
of messages that consumers wish to receive. The INFOD Registry is then
responsible for matching subscriptions to the available publishers, and
then invoking an operation on the publisher to indicate the set of consumers
to which it should send notifications. (The Registry is a bit like a NotificationBroker,
but notifications flow directly from producer to consumer rather than through
the broker).

The only item from WSN that seems to
be used in the Notify operation (mainly covered in section 3 of the INFO
doc attached). My primary concern is whether the INFOD folks are intending
to take a copy of the Notify operation, or use the one we define in WSN.
There are several areas in the document (notably the Schema document in
5.10 and parts of 3.1.1) where they seem to copy the Notify operation into
an INFOD namespace, which strikes me as a pretty weak form of reuse (ie
regular WSN apps wouldn't be able to invoke this new variant of Notify
because of the different namespace). They also define a new WSA Action
URI to be used when invoking this Notify operation, which is a violation
of the WSN spec (if they are trying to reuse rather than copy).

I have attached comments in the document
below that highlight the specific areas that I have identified - I think
is would still be very useful for someone from INFOD to present to the
WSN committee to give some more background on how this will be used and
clear up any misconceptions I may have stumbled into!

Cheers,

Matt


Matt Roberts
IBM WebSphere Messaging Design and Development
Hursley Park, England. +44 1962 815444
matt.roberts@uk.ibm.com
MP 211 / DE3H22

INFOD-Base Specification.doc