On Mon, 17 Feb 2003 at 17:17:18 -0500 Oskar Batuner avowed, in replying
to Alex Rousskov:
> It looks like the big question here is about control over user
> preferences. To me, it seems unreasonable to assume that all user
> preferences are handled at the OPES processor. It is just too rigid of
> a model and often very inefficient since the processor knows very
> little about filtering and the filter (OPES server) may need to know a
> lot. If we restrict user preference handling to OPES processor, we end
> up passing a lot of preference information to the OPES server just so
> that it can process a transaction.
I'm afraid we are going too deep with analysis of this specific scenario.
If I understand correctly Martin used preferences just as an example of
the reason why callout processor may produce multiple responses
for a single request.
Discussions that reveal schisms in the meaning of the architecture are
very important, whether or not it was the intention of the original
message. The lack of specifics to date has been difficult for everyone,
and I'm sure that there are more surprises lurking as we discuss a real
protocol for real uses.
There may be any number of reasons for the callout processor to
produce multi-message response, the protocol just SHOULD (MUST?) support
multiple responses while preserving transactional integrity.
We should not (MUST NOT) impose any limitation on what
information is available to the callout processor (including
preferences) and how OPES processor and callout processor assign
tasks between themselves while performing a collaborative
processing - this is application specifics and should be
out of scope for protocol design.
I think it's not as collaborative and loose and all that. The OPES processor
is the enforcement point for privacy. It's designed to be a very fast
and fine-grained, policy-based, application-layer switch. If it is not
the repository for user preferences, then all the policy enforcement
and authentication requirements get pushed to the callout servers. This
leaves the OPES processor with almost no function - it might as well be
a dumb hardware switch operating at layers 4 through 7.
Hilarie