The stream and rule models can potentially be merged.
I suspect the Rule Model and Streams Model are isomorphic, though I
haven't actually tried to develop a proof.
This ordering can also be achieved by attaching modules to specific
processing phases
as you suggest. However, a rule-based approach is more general and more openly
extendible that a phased processing model.
The phase-based approach may make it easier for applications developed
independently to be integrated automatically. For example, the ordering
of actions from different applications within a given phase may be
irrelevant due to the nature of the processing defined for that phase.
I have concerns that if the model is too flexible then automatic
integration will not be possible at all. Of course, application
integration is a non-computable problem in the general case, but an
appropriate model may make it possible to do for many/most common cases.
However, using declarative trigger rules to
pre-screen the proxy to decide whether it should run on this request/response
is
useful.
Agreed. I defined the Streams Model to do this, but presumed it would
be less fine-grained in the screening than in the Rule Model.
As I said, I suspect the Rule Model and Streams Model are isomorphic,
and the use of one or the other processing model will mean more to the
underlying proxy architecture and the exposed programming model than to
the actual functionality of the system.
Regards,
Steve Moyer