Re: OPES Rules Language

On Thu, 2005/06/09 (MDT), <[email protected]> wrote:

> At 18:55 09/06/2005, Alex Rousskov wrote:
>> On Thu, 2005/06/09 (MDT), <[email protected]> wrote:
>>
>>> Some difficulty to understand how you trigger the adaptation then?
>>
>> The proxy/processor configuration will have a mechanism to specify
>> what rules/code to apply and where to apply them. Different processors
>> will have diffierent invocation points and different specification
>> mechanisms (e.g.,access control lists or hard-coded triggers).
>
> This does not make the language universal.

No language can be universal. Think about it. Somewhere the language
scope ends and the language environment scope begins. For example,
C++ standard does not specify when C++ programs are executed while
shell scripts do not care what language the programs they run were
written in.

The reason to remove invocation points from the rules language
is simple: all existing proxy implementations already have their
configuration language that determines invocation points. Usually,
it comes in a form of an ACL of some sort. Apache, Cisco, NetApp,
sendmail, etc. all have that. Trying to change or replace that
language is fruitless, IMHO.

On the other hand, providing a universal language to describe what
(if anything) happens at the selected invocation point does have a
[slim] chance of being deployed because no popular implementations
(related to HTTP and ICAP) have any good knobs for that. SMTP world
has Sieve and Milter.

> Objection to have both?
> Obviously I can add them but that would be bad if the language ends to  
> be in an ISO standard what would be great.

Sorry, I do not understand this part. Perhaps you can give a specific
ISO requirement you are trying to satisfy?

Alex.