Tom Rutt wrote:
From the minutes of 6/14 meeting, My comments
new to this email start
with <ter> tag
"
2b) The one-way consumer interface and Response
RM-Reply pattern is the
most direct combination to reliably
deliver one-way messages from a
producer "hidden" behind a firewall.
The matrix in section 5.2 should
not disallow this combination.
While synchronous polling at least
works, it always requires an additional round
trip.
<ter> one of Sunil's objections to the above proposal is based
on the
BP 1.0 restriction.
I Quote from BP 1.0a of WS-I
"
5.6.10 One-Way Operations
There are differing interpretations of how HTTP is to be used when
performing one-way operations.
R2714 For one-way operations, an INSTANCE MUST NOT return a HTTP
response that contains a SOAP envelope. Specifically, the HTTP response
entity-body must be empty.
R2750 A CONSUMER MUST ignore a SOAP response carried in a response from
a one-way operation.
R2727 For one-way operations, a CONSUMER MUST NOT interpret a successful
HTTP response status code (i.e., 2xx) to mean the message is valid
or
that the receiver would process it.
One-way operations do not produce SOAP responses. Therefore, the Profile
prohibits sending a SOAP envelope in response to a one-way operation.
This means that transmission of one-way operations can not result in
processing level responses or errors. For example, a "500 Internal
Server Error" HTTP response that includes a SOAP message containing
a
SOAP Fault element can not be returned.
The HTTP response to a one-way operation indicates the success or
failure of the transmission of the message. Based on the semantics
of
the different response status codes supported by the HTTP protocol,
the
Profile specifies that "200" and "202" are the preferred status codes
that the sender should expect, signifying that the one-way message
was
received. A successful transmission does not indicate that the SOAP
processing layer and the application logic has had a chance to validate
the message or have committed to processing it.
Despite the fact that the HTTP 1.1 assigns different meanings to
response status codes "200" and "202", in the context of the Profile
they should be considered equivalent by the initiator of the request.
The Profile accepts both status codes because some SOAP implementations
have little control over the HTTP protocol implementation and cannot
control which of these response status codes is sent.
"
<ter> the requirements seem tied to HTTP transport binding for SOAP,
rather than to SOAP in general. However the first two sentences of
explanatory text is written regarding Soap in general.
"
The BP requirement may be tied to Http, but as I mentioned umpteen
no. of times
on the call and as always you keep interrupting me without
listening completely, I was
saying that the abstract part of the WSDL one-way operation
prohibits a response.
Infact, let me re-quote a snippet from what you quoted:
" One-way operations do
not produce SOAP responses. Therefore, the Profile
prohibits sending a SOAP envelope in
response to a one-way operation.
This means that transmission of one-way
operations can not result in
processing level responses or
errors."
Let me also cut-and-paste the snippet from the WSDL 1.1
spec. regarding the
one-way operation:
2.4.1 One-way Operation
The grammar for a one-way operation is:
<wsdl:definitions .... > <wsdl:portType .... > *
<wsdl:operation name="nmtoken">
<wsdl:input
name="nmtoken"? message="qname"/>
</wsdl:operation>
</wsdl:portType >
</wsdl:definitions>
The input element specifies the abstract message format for the one-way
operation.
Note that there is no output or fault definition for a one-way
message.
What BP did is re-inforcing what is said in WSDL 1.1 spec. and
clarified what to do in Http case
as the latter is request-response transport.
What I'm still not clear on Doug's issue 2(b) is how to employ
a Response RM-Reply pattern
for a one-way WSDL operation.
I fully understand and agree that usage of word MEP in section
5.2 is misleading and corrected.
I also agree that one-way consumer interface MAY be mapped to
a R-R binding/operation and
thus CAN be used with a Response RM_Reply pattern.
But, section 5.2 is NOT about Consumer interfaces, rather WSDL
1.1 operation types.
With that context, I don't see anything wrong with that table.
I don't see how the combination of one-way consumer interface
and Response RM-Reply pattern
is the most used one. To me this is the least used one as most
likely a one-way consumer interface
will be mapped to a one-way WSDL operation and hence a one-way
binding. I'd assume Callback
pattern to be the most commonly used pattern in that scenario.
-Sunil
