W3C

XML Protocols Telcon of 29 March 2006

29 Mar 2006

Agenda

See also: IRC log

Attendees

Present
BEA Systems, David Orchard (DO)
IBM, Noah Mendelsohn (NM)
Nokia, Mike Mahan (MM)
Oracle, Anish Karmarkar (AK)
Sun Microsystems, Marc Hadley (MH)
Tibco, David Hull (DH)
W3C, Yves Lafon (YL)
Regrets
IBM, Chris Ferris
Sun Microsystems, Pete Wenzel
Absent
Ericsson; Nilo Mitra
Iona Technologies,
Sonic, Glen Daniels
Sonoa Systems, Vikas Deolaliker
Excused
Oracle, Jeff Mischkinsky
Chair
Mike Mahan
Scribe
Noah Mendelsohn

Contents


<scribe> agenda: http://lists.w3.org/Archives/Member/w3c-xml-protocol-wg/2006Mar/0023.html (Member-only)

Agenda Review

MM: Yves, anything to announce from W3C CG?

YL: New pubrules in place. Need to check documents as we publish.
... I'm not sure what changes were made. I just use the pubrules checker.

MM: Any other agenda items?

(silence)

Approval of minutes

MM: David Hull -- need update on March 4 minutes

DH: Thought I did it.

MM: Please check.

DH: Will do.

<Yves> http://lists.w3.org/Archives/Public/xml-dist-app/2006Mar/0008.html

Note pending March 4 minutes are at http://lists.w3.org/Archives/Member/w3c-xml-protocol-wg/2006Mar/0006.html

RESOLUTION: Minutes of 22 March 2006 at http://lists.w3.org/Archives/Member/w3c-xml-protocol-wg/2006Mar/0022.html are approved

DH: http://lists.w3.org/Archives/Public/xml-dist-app/2006Mar/0008.html is log of 4 March

MM: Sorry, missed that.

DH: It has been "massaged"

MM: I'll republish today.

Action items

2006/03/04: Anish

Start email discussion on what FAF really means.

<scribe> CLOSED.

MM: Will discuss later today.

2006/03/04: Noah

Suggest how the group should proceed in reviewing draft

Was: PENDING - Deprecated.

MM: Noah and I discussed last week. I've given promised rollup of input received so far. Noah, comments?

NM: The consolidated comments are very helpful. I think we need to get to the point where we have agreement from the group as to what the exact list of changes is. Clearly we need to settle 202 vs. 204.

<scribe> ACTION: Yves to check pubrule changes to see whether any need advance review by our WG [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action01]

The action above to Noah is CLOSED

2006/03/04: Yves

Propose resolution for rec42

<scribe> CLOSED

SOAP 1.2 PER

MM: Would like to go through comments.

From the agenda:

MM: Lets first deal with Anish's issue while he is on the call, then jump back to this.

Meaning of FAF

See: http://lists.w3.org/Archives/Public/xml-dist-app/2006Mar/0031.html

AK: At F2F we talked about difference between UDP vs. inherently req/resp protocol where a response flows on a backchannel, and there sre timing issues of waiting for the response.
... I sent email with my thoughts. Not convinced we need to do two MEPs, one way vs. FAF.
... Not sure we can quantify timing issues.
... This is an abstract MEP anyway, somewhat indepedent of actual on the wire flows.
... Even when sending UDP, there are issues of waiting for local calls to complete
... The abstract MEP is somewhat different from API. Could be mapped to API, but could also map same MEP lots of ways.
... Threads, workqueues etc. let you get the appearance of non-blocking even when there's more work to do.

AK. You can get the same kind of errors on UDP send

NM: I agree that we dont need 2 MEPs in this space

NM:I think that bindings like HTTP should support the existing R/R and R/O, and not any new one-way
... The transports like UDP, JMS, MQ that are inherently "do a bit of work locally, and then you're done" should support the one new mep
... Anyway, we should do one new MEP. Maybe or maybe not we should say something about timing, but we should aim to work well on UDP, JMS, etc.

DH: Like Anish, I'm nervous about quantifying timing. Also agree we're talking about abstract MEP.
... Also agree things like UDP can reflect errors, e.g. on bad IP address.
... I agree with Noah that there will basically be two worlds, r/r and one-way
... Glad to see lots of agreements.
... Useful to look at obligations incurred when using MEP. For example, in R/R, receiver is expected to respond.
... If not, there's a failure (something catastrophic with plumbing related to us) as opposed to fault (from outside)
... With FAF, faults don't necessarily happen.

(Noah thinks they happened, but aren't routed anywhere beyond the node on which they occur.)

DH: By contrast in R/R, you are expected to generate and "make known" the fault.
... Receiver is not obligated to do anything SOAP'y with errors in one-way
... oops, using one-way and FAF interchangeably
... That's why FAF doesn't fit well on HTTP, but if you insist on doing it, you have to look at it that way.

<marc> (marc think the same applies to RR, generate != send)

DH: Yves mentions SMTP. Yes I can address responses, but I claim it's mostly one-way.
... Yes someone will tend to send reply confirmation, but not necessarily the ultimate receiver.
... Being able to address response and do response are somewhat orthogonal.

(Noah agrees.)

MH: My point is that even in R/R the responder isn't required to do anything with the fault.

NM: I think the spec says do it.

MH: Can cut connection.

NM: I think cutting the connection is a response to a different error, such as denial of service.

MH: In the absence of getting a response, the requestor knows as much in the one way case as with r/r

NM: I disagree. If a connection closes with no resp in r/r you know there's an error.

MH: not convinced.

AK: I like David Hull's characterization regarding responder responsibilties.
... I think I also agree with Noah that we don't need to bind the new one-way FAF or 1-way to HTTP.
... I'm not as convinced as Noah that you shouldn't do, e.g. r/r over UDP-like, but you do have work to do to add infrastructure.
... Where does TCP fit.

<anish> my concern is that we are tieing MEPs more and more closely to transport

<anish> which is why i was advocating getting rid of MEPs ;-) some time back if we want to do that (tie MEP close to transport)

NM: mostly I'm saying that the two worlds aren't completely disjoint, or that we won't ever need a 2nd MEP, but rather that we can get away with one now.
... I'm proposing we draw the line at MEPs meant to be used with transports that require no interaction with the network in order for the sender to complete work (in the typical case)

DH: curious accident that we never said what it is to send a simple message
... I'll probably push for light weight, because we'd meet that basic need.

MH: I think MEPs as currently defined don't talk about the kind of thing we're talking about now.

<dhull> agree with Marc about binding vs. MEP and which details MEP leaves out

(noah thinks the Response-only MEP has always talked about binding-level flows and synchronization)

<anish> +1 to marc

<Zakim> dhull, you wanted to re-state a main objective

MM: Do we agree, e.g. on Anish proposal on naming. Lets capture here our points of agreement

NM: Suggestions: (1) we agree on doing one MEP (2) call it one-way (3) it captures what David Hull said about sender/receiver responsibilities (4) we're ready to draft preliminary text (5) however we don't yet have agreement on timing issues...let someone draft text and we'll debate from there

<marc> sounds good

<dhull> I think we also agree that transport failures (as opposed to faults) are always possible (but the sender can't count on hearing about them)

<scribe> ACTION: Editors (Anish, David Orchard, and Chris Ferris) to draft proposed text for one-way MEP. See minutes of 29 March for details. [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action02]

NM: Let me take a flyer on text on timing: "Note: this MEP is meant to be implementable on transports such as UDP and JMS and MQ, which have the characteristic that senders can queue messages and then proceed without interacting through the network with receivers." Not sure that's good, but maybe something like that.

DH: I think there have been some previous attempts by Dave Orchard and others to do drafts of such MEPs.

<scribe> ACTION: David Hull to look through archives of async task force to find earlier drafts of one-way MEPs [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action03]

MM: thanks noah – agreed



SOAP 1.2 PER (redux)

Thread start:

http://lists.w3.org/Archives/Public/xml-dist-app/2006Jan/0037.html

Reworked proposal:

http://lists.w3.org/Archives/Public/xml-dist-app/2006Jan/0050.html

HTML Part2 proposal:

http://www.w3.org/2000/xp/Group/2/06/LC/soap12-part2OptRespMEP.html

Consolidated comments:

http://lists.w3.org/Archives/Public/xml-dist-app/2006Mar/att-0026/consolidated_comments.txt

MM: There were interleaved comments, comments on comments, etc. Hard to consolidate.
... I found (a) 4 purely editorial (b) 3 substantial
... Can we move forward on some even with out Chris Ferris, who isn't here?

DO: Might be better to wait for Chris, I'm not "swapped in".

MM: Let's start with SC1, a non-Chris issue

Issue: If we are using 202 as indicated in Table17, there should be clarification on the semantic: that any SOAP envelope would not represent the results of processing the inbound SOAP message. It only indicates an intermediate result, like an ack.
... If we are using 202 as indicated in Table17, there should be clarification on the semantic: that any SOAP envelope would not represent the results of processing the inbound SOAP message. It only indicates an intermediate result, like an ack.

NM: This accurately describes what people are doing. Is it OK use of HTTP.

<Yves> <<< (rfc2616)

<Yves> The entity returned with this response SHOULD include an indication of the request's current status... >>>

YL: so everything seems to be about the request.

MM: What's the conclusion?
... Relative to 202 vs. 204

YL: Mark B seems to be saying we should document how we're using 202.

NM: The text I've drafted says "envelopes not expected with 202. If one is there, SOAP processing of it is beyond the scope of this spec." That sounds right to me.

DO: ... Let's consider something in an HTTP request, perhaps an envelope with an RM header. Let's say there's an acknowledgement in there. Looks fine to me.

Noah is curious: would it be just as fine if the request had no RM header?

DO: I think the RM header is always there.

NM: Are we agreeing that this all points in favor of rejecting the requested edit?

DO: Yes, I think so.

MM: Other opinions?
... we should inform Mark of why we're going here.
... volunteers?

YL: Wait for 202/204 discussion?

<dhull> Dave O's one-way MEP proposal: http://lists.w3.org/Archives/Public/public-ws-addressing/2004Dec/0159.html

MM: OK
... Noah?

NM: Agreed.

MM: I'll wrap this into the comment note, text wrap it, but otherwise we'll wait.

<dhull> my cut: http://lists.w3.org/Archives/Public/public-ws-async-tf/2005Mar/0006.html

SC2

Proposed text:

From: 'The response message MAY contain a SOAP envelope, or else the response MUST be a binding-specific message indicating that the request has been received.'

To(1): 'The response message is a binding-specific response that MAY contain a SOAP envelope.'

To(2): The SOAP Request-Response MEP defines a pattern for the exchange of a message acting as a request optionally followed by a message acting as a response. The messages may or may not carry SOAP envelopes. In the absence of failure in the underlying protocol, this MEP consists of one request message and one optional r

and one optional response message:"

NM: I'm not sure the From/To line up as talking about the same thing. The To: looks like text that's already here.

DO: We have 3 commentors including Noah that need to be here, and Noah's not here next week.

<scribe> ACTION: Mike Mahan -- start email discussions of summarized issues SC2 and SC3 [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action04]

MM: Yves, can we talk a bit about 202/204, and then I'd like to talk about what WSA wg has done with 202 vs. 204

YL: Sure. We need to decide 202/204/200(length=0).
... Says roughly "I got the request, and won't tell you about its processing."
... 202 says roughly "I got the request, and won't tell you about its processing."
... 204 says roughly "If you put a mustUnderstand header, I would have checked it."
... 204 cuts message channel but not error channel. 202 cuts both.

From 2616, status code 204:

The server has fulfilled the request but does not need to return an

entity-body, and might want to return updated metainformation. The

response MAY include new or updated metainformation in the form of

entity-headers, which if present SHOULD be associated with the

requested variant.

NM: That looks to me like 204 is only for the case where you have completely fulfilled the request.

DO: Are you encouraging 204 vs. 202?

YL: Yes.

DO: Well, even notwithstanding architectural purity, it's just not what's happening.

NM: I'm still not convinced that 204 is even more appropriate architecturally, Combining that with what Dave says about widespread practice, and 202 seems like the answer.

YL: Do we need to say anything about, e.g. mU checking having been done?
... We might need to say something more specific than HTTP does as to how SOAP is using this. E.g. whether mU processing is necessarily done.

MM: Running out of time. Can we move to the mailing list?

<scribe> ACTION: Yves to start email thread on whether we need to say more about use of 202 and 204, including whether we need to discuss header processing if 202 is used. [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action05]

MM: Looks like we'll have to defer WS-Addressing work on SOAP 1.1.
... Adjourned

Summary of Action Items

[NEW] ACTION: David Hull to look through archives of async task force to find earlier drafts of one-way MEPs [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action03]
[NEW] ACTION: Editors (Anish, David Orchard, and Chris Ferris) to draft proposed text for one-way MEP. See minutes of 29 March for details. [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action02]
[NEW] ACTION: Mike Mahan -- start email discussions of summarized issues SC2 and SC3 [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action04]
[NEW] ACTION: Yves to check pubrule changes to see whether any need advance review by our WG [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action01]
[NEW] ACTION: Yves to start email thread on whether we need to say more about use of 202 and 204, including whether we need to discuss header processing if 202 is used. [recorded in http://www.w3.org/2006/03/29-xmlprotocol-minutes.html#action05]
 
[End of minutes]


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