12/13/2004 4:55 PM
post4036
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Minutes from 2 Dec call
Attending:
Dieter
Steve
Abdeslem
Vijay
Susan
Cecile
Chris (minutes)
- Susan sent notes about the key points of infod and how it relates to wsn:
* Basics
o Producers determine the consumer of each message by
specifying a distribution list. This is idea is borrowed from the e-mail
model, the following bullets will show that INFOD significantly extends
the e-mail model
o The distribution can be based on a list of names, a
selection derived from one or more registries, and a mix thereof.
Entries from the registries are selected using a query language.
o If the registry contains subscriptions, producers may use
these subscriptions to determine the consumers. Producers may select
only based on subscriptions or use subscriptions in conjunction with
other information when (publish/subscribe as well as mutual filtering)
o Producers can adjust the content of each message to each
consumer, based on consumer and/or producer interest and/or policies
o Producers may determine on a message basis which
subscription is honored. This provide the equivalent of row level security.
o Producers may use any delivery mechanisms that is available
to each consumer. Different delivery mechanisms may be used for
different consumers even for the same message.
o A topic, bus, and/or messaging system can act as producer
and/or consumer. This allows the represent the world of JMS and other
messaging systems.
* There are three types of publications
o Unconditional publications - a message is published
regardless of the interest of consumers (no impact of consumers on
publication - INFO and WSN)
o Demand based publication - a message is only published if
there is interest (consumers determine if an instance of a publication
is worth to be publish - INFO and WSN)
+ The evaluation of subscriptions happens before a
message is created
+ The evaluation of the subscriptions happens after a
message has been created.
o Subscription based publication - the creation of messages
is the result of subscriptions (This is by far the most flexible way to
create publications - INFOD only)
* Discovery of producers and consumers is important to spell out.
It is a consequence of the function described in the first top bullet. I
have nothing to add to Susan's bullets.
* The next paragraph discuss propagation and its operational
characteristics. I will edit this once we have discussed the subject.
still need to discuss (at another time) the use of registries in infod
- OGSA thinks "information services" has no activity in GGF - what
gives? We think INFOD is relevant, in particular, INFOD is
"information delivery".
How do we best get more involved/recognized in OGSA? A. will try
to get the GGF13 OGSA draft to be consistent with INFOD.
- F2F in Redwood Shores Jan 13/14 to go over the spec doc in detail.
Next call in two weeks, 12/16.
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