Here is a list of open issues concerning IRML and rule processing:
1) In what order should the rule engine process rule modules by client,
content provider and access provider?
The current IRML draft proposes the order following the content flow, i.e.,
the requests from the client to server (at point 1 & 2) should be processed
in the order of client, access provider to content provider, while the
responses (at point 3 and 4) should be in the order of content provider,
access provider to client. This order may not always make business sense to
the OPES box owner. One can argue that the exact order should be left
outside of the rule engine and other external factors such as business
arrangement or administration policy could dictate the order in any way.
Following this argument, the ordering infomation can be completely left
outside of the IRML and be part of the configuration or policy info on the
OPES device. Thus the question becomes how and in what form, what
granularity such order infomation should be passed to the OPES device?
2) How many and what kind of processing points should we define for OPES
devices?
Currently there are 4 clearly-defined processing points in the OPES
framework and these points are very much cache-oriented. Are there any
additional points that people see useful for other intermediary devices or
applications? Should these points be defined statically at the configuration
time or dynamically on the fly? (Actually I don't see how it can work
dynamically since the rules are written for a specific processing point in
IRML, hence the processing points need to be well-defined to be
interoperable.)
3) What kind of environmental variables need to be supported in IRML?
Currently we have time and day. Anything else? How do we support condition
like "when the server load is low..." ?
4) Currently IRML supports only regular expression for condition matching.
Do we see a need for other kind of conditions, like arithmetic support? This
is related to question 3). Regular expression isn't so handy for conditions
like "for every 5 minutes", or "if the load is below 25%" etc.
5) Currently IRML supports only static and exact action binding in the
<action> element. It is proposed that late and flexible (or not-exact)
action binding might also be desirable. How can IRML facilitate both? In
another word, how can we allow people to say "do exactly this translation
service by this vendor at this location", or "just do whatever virus scan
you have".
6) Do we allow multiple rule modules from the same content provider (for
different level of domains)? One example is to have one general rule module
for intel.com and another more specific rule module only for www.intel.com.
Since the ID attribute in the <owner> element really identifies the domain
boundary that the rule module is applicable to, it seems legal to have both
rule modules in place and it also seems logical to apply both rule modules
for content inside www.intel.com domain. Does it make sense? What about the
order then? Should it be the general module (intel.com) first followed by
the more specific one (www.intel.com)?
7) what kind of rules make sense for streaming media instead of web content?
Feel free to add to it.
Lily
-----Original Message-----
From: Yang, Lily L [mailto:lily(_dot_)l(_dot_)yang(_at_)intel(_dot_)com]
Sent: Tuesday, June 05, 2001 8:48 AM
To: ietf-openproxy(_at_)imc(_dot_)org
Cc: Andre Beck (E-mail); 'hofmann(_at_)bell-labs(_dot_)com'
Subject: issues on IRML & rule processing for OPES
Hi, all
In preparation for the upcoming OPES interim meeting, we would like to
compile a list of open issues regarding IRML and rule processing in general.
I will go back to the mailing list archive to dig out the issues that we've
discussed so far. Meanwhile, it would be very helpful if you bring any
issues, doubts, suggestions, etc. in this area to the group's attention
before the meeting. Feel free to repost any issues that we discussed before
so it would not be missed.
Thank you all,
Lily