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HTTP based async request-response

From: Marc Hadley <Marc.Hadley@Sun.COM>
Date: Wed, 02 Feb 2005 16:45:34 -0500
To: public-ws-async-tf@w3.org
Message-id: <60534727fceb9328723032a4b08d1003@Sun.COM>

I took an action to outline one approach to async request-response 
using HTTP. Basically the request is sent as normal as the entity body 
of a HTTP POST request but instead of returning the response in the 
HTTP entity body, the server responds with a 303 (See other) status 
code and includes a Location header that gives a URI from which the 
response can be retrieved. The client then uses a new HTTP GET request 
to retrieve the response. E.g.

Initial request:

POST /StockQuote HTTP/1.1
Host: stockquote.example.com
Content-Type: application/soap+xml
Content-Length: nnnn

<env:Envelope xmlns:env="...">
    ...
</env:Envelope>

Response:

HTTP/1.1 303 See Other
Location: http://stockquote.example.com/someuniqueidentifier
Retry-After: 120
Content-Type: text/html
Content-Length: 0

Susequent request to retrieve response:

GET /someuniqueidentifier HTTP/1.1
Host: stockquote.example.com

Response:

HTTP/1.1 200 OK
Content-Type: application/soap+xml
Content-Length: nnnn

<env:Envelope xmlns:env="...">
    ...
</env:Envelope>

If the response isn't yet ready the server can send back another 303 
indicating when the request may be retried using the Retry-After 
header.

I quite like this approach since it pushes the asynchrony down into the 
HTTP layer and doesn't require anything new in WSDL or SOAP. The 
existing SOAP 1.2 HTTP binding supports this usage.

Marc.

---
Marc Hadley <marc.hadley at sun.com>
Web Technologies and Standards, Sun Microsystems.
Received on Wednesday, 2 February 2005 21:45:36 GMT

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