Re: [DS8] Conversational message exchange - revised

john_ibbotson@uk.ibm.com wrote:

> DS8  Two trading partners are engaged in a long-running business process
> which involves multiple  message exchanges. ....

John -- as we discussed yesterday, I would like to see this case accomodate the
information retrieval scenario.  Could we expand it to include this:


Two partners are engaged in an information retrieval session which involves
multiple message exchanges, and multiple message patterns.

This information retrieval scenario is modeled in terms of a client/server
protocol; one partner is the client who wants to retrieve information from the
other partner, the server.

Inititially, the partners may exchange messages to set and/or negotiate
parameters that will be in effect for the remainder of the process. The client
may then send a query and the server responds with a count of documents
resulting from processing the query.  The client may then request transmission
of the first N documents (full text of the documents, specified portions only,
or just metadata) then the next N documents, and so on. The client may
subsequently send another query (thus a second result set would be created),
request resulting documents, and might subsequently request additional documents
from the first result set.

Message exchange is patterned mostly in terms of request/response messages (e.g.
for negotiation, query, and document retrieval) where the client sends a request
and the server sends a response. However, there are some messages that the
client may send that require no response. There are also messages that the
server may send asynchronously; for example, the client may send a request (a
query) and the server might send a message requesting clarification about the
query; the client then sends the clarification, and subsequently the server
sends a response to the query.



--
Ray Denenberg
Library of Congress
rden@loc.gov
202-707-5795

Received on Thursday, 18 January 2001 10:37:34 UTC