Re: Correlating SOAP Requests/Responses - For Multiple Outstanding requests

Tom Miller writes:

>> In other request/response protocols such as Remote Operations, there is
>> a unique object (called an Invoke ID) that is passed in the request and
>> also passed back in the reponse so that the application can correlate
>> the response to the appropriate outstanding request message.

>> Is there anything already defined in SOAP that would provide the same
>> sort of  function?

First a meta-question:  did you intend to send this to dist-app, which is 
devoted primarily to the evolution of SOAP and related protocols, or to 
the SOAP mailing list, which is about using SOAP.  The latter is at: 
soap@discuss.develop.com.

Anyway, I think the answer is that in SOAP, such correlation can be 
accomplished with the aid of particular bindings, in association with some 
particular API that you may be using to invoke SOAP.  In the case of HTTP, 
each request/response is a separate HTTP connection, so you know which is 
which:  if you're programming SOAP yourself at the HTTP level, just use 
your own OS APIs to keep track of which request is which.   On other 
transports, one can imagine the binding adding an ID cookie to do the 
correlation.  Now, as to whether any given  implementation makes it easy 
to keep track of multiple outstanding requests, you should check with the 
supplier of that implementation.  It's not a feature of the protocol.

>>  could this element be provided in the SOAP header 
>> or does SOAP require that this be
>> provided in the SOAP body?

The body is just a header that carries the main data for the message, 
another header is more likely.  Actually, just as appropriate is data 
added by the binding outside of the XML envelope (i.e. neither header nor 
body...think of SOAPAction in the http binding as an example of such 
binding-specific data.)

------------------------------------------------------------------------
Noah Mendelsohn                                    Voice: 1-617-693-4036
Lotus Development Corp.                            Fax: 1-617-693-8676
One Rogers Street
Cambridge, MA 02142
------------------------------------------------------------------------







Tom Miller <Tom.Miller@icn.siemens.com>
Sent by: xml-dist-app-request@w3.org
02/05/2001 08:17 PM

 
        To:     xml-dist-app@w3.org
        cc:     (bcc: Noah Mendelsohn/CAM/Lotus)
        Subject:        Correlating SOAP Requests/Responses - For Multiple Outstanding requests


I have an environmnet  where there  may be multiple requests for the
same SOAP Action outstanding at any one time. In this case the
application cannot associate the response to the issuing request by just
checking the SOAP Actions in the resquest/response messages (i.e. with
the appended "response" text in the response).

In other request/response protocols such as Remote Operations, there is
a unique object (called an Invoke ID) that is passed in the request and
is also passed back in the reponse so that the application can correlate
the response to the appropriate outstanding request message.

Is there anything already defined in SOAP that would provide the same
sort of  function?

If not, and a new element is added to provide an InvokeID function,
since this is independent of any specific SOAP action, could this
element be provided in the SOAP header or does SOAP require that this be
provided in the SOAP body?

Regards,
Tom Miller

Received on Tuesday, 6 February 2001 16:40:15 UTC