[standards-jig] Pubsub "Real World" Implementation Issue
bob at wyman.us
Wed Jul 23 16:18:04 UTC 2003
Stephen Pendleton wrote:
> I want the client to automatically discover and
> subscribe to the location node of each user
I suggest that you consider using a method similar to the
"Topics" topic that I proposed in the now expired "PubSub over APEX"
Internet Draft. 
Have your PubSub server host a node that publishes announcements
of new nodes as they are created or have their configuration parameters
modified. Clients would then subscribe to this node and be notified
whenever a new node was created. You would define some chunk of XML that
would provide a "new node" announcement or advertisement. Ideally, this
should contain information like a description of the node, the identity
of its creator, potentially statements about intended use of published
data, the date of creation, etc.
Ideally, there would be a JEP written to form a common
understanding of what information should be published when a new node is
created or modified. I expect that the node "announcement" or
"advertisement" would be passed as part of the node configuration data.
Also, an ideal system should provide an option on node creation that
allows the creator to say whether or not the node should be announced --
or just created silently.
This approach of having the server publish announcements of new
and modified nodes will be found to be useful in enabling a wide range
 In APEX, we spoke of "topics" not "nodes" even though the two words
appear to refer to the same concept. "Topic" is the word that has been
traditionally used by PubSub researchers and implementers in the past
for quite some time...I'm not sure why JEP-0060 decided to create new
vocabulary by insisting on naming things as "nodes"... JEP-0060 defines
what is almost universally referred to in the literature as a
"topic-based" PubSub system.
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