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RE: Straw poll on "synchronous" definitions

From: Cutler, Roger (RogerCutler) <RogerCutler@chevrontexaco.com>
Date: Fri, 14 Mar 2003 21:22:55 -0600
Message-ID: <7FCB5A9F010AAE419A79A54B44F3718E01624BA3@bocnte2k3.boc.chevrontexaco.net>
To: "David Booth" <dbooth@w3.org>, www-ws-arch@w3.org

Ugo-2c is not my favorite definition, but I am absolutely willing to
accept it ... For "asynchronous".  I am not, however, real keen on
defining synchronous as "The opposite of asynchonous".  Perhaps I am
being presumptuous, but I don't think that Ugo really meant this as
anything more than a placeholder.  So, as far as I am concerned ...
Fine, but only if someone comes up with a reasonably parallel definition
for synchronous.

-----Original Message-----
From: David Booth [mailto:dbooth@w3.org] 
Sent: Friday, March 14, 2003 5:58 PM
To: www-ws-arch@w3.org
Subject: Re: Straw poll on "synchronous" definitions

Here are the results of the straw poll on the definition of 
"synchronous".  Based on these results, I suggest that we:

1. Take definition ugo-2c (see 
http://lists.w3.org/Archives/Public/www-ws-arch/2003Mar/0074.html) as a 
starting point.
2. See if everyone can agree to the essence of that definition. If so,
   a. See if anyone wishes to make any minor modifications
      (i.e., friendly amendments); and
   b. Adopt the result.
If not, then:
   c. Try to combine two or more of the candidate definitions.

------------------------ Straw Poll Results -----------------------
Results for poll: 
Raw ballots are at: 

BallotCode: <FB-sync>
MaxVotesPerVoter: 3
Number of voters: 14

Vote Totals (Weighted)
(Votes were weighted linearly, with top preference getting 3 points.)
     Choice Points
   ugo-2c  16
ferris-1  13
  geoff-1   9
cutler-1   8
dbooth-2   8
  frank-2   6
  frank-1   5
dbooth-1   4
moberg-1   4
walden-1   2
  assaf-3   2
  assaf-2   1

Votes by Sender
     1  geoff-1 (3 points)
     2   ugo-2c (2 points)
     3 cutler-1 (1 points)

     1  geoff-1 (3 points)
     2 walden-1 (2 points)
     3   ugo-2c (1 points)

     1   ugo-2c (3 points)
     2 dbooth-2 (2 points)
     3 cutler-1 (1 points)

     1 dbooth-2 (3 points)
     2 cutler-1 (2 points)
     3 ferris-1 (1 points)

     1   ugo-2c (3 points)

     1  frank-1 (3 points)

     1 ferris-1 (3 points)
     2 cutler-1 (2 points)
     3  assaf-2 (1 points)

     1 dbooth-2 (3 points)
     2 dbooth-1 (2 points)
     3 ferris-1 (1 points)

     1  frank-2 (3 points)
     2  frank-1 (2 points)
     3 ferris-1 (1 points)

     1 ferris-1 (3 points)
     2   ugo-2c (2 points)
     3 moberg-1 (1 points)

     1   ugo-2c (3 points)
     2 dbooth-1 (2 points)
     3 ferris-1 (1 points)

     1 ferris-1 (3 points)
     2  assaf-3 (2 points)
     3 moberg-1 (1 points)

     1  geoff-1 (3 points)
     2 moberg-1 (2 points)
     3 cutler-1 (1 points)

     1  frank-2 (3 points)
     2   ugo-2c (2 points)
     3 cutler-1 (1 points)


At 11:22 AM 3/11/2003 -0500, David Booth wrote:

>At the end of our F2F meeting, I took an action to poll the working 
>group on the many "synchronous" definitions that were proposed. This 
>poll is not intended to decide on the definition of "synchronous" 
>directly, but only to narrow the field.  Once we have narrowed the 
>field, I will try to make adjustments as needed to reach consensus on a

>common definition.
>[Ballot form adapted from http://www.debian.org/vote/howto_vote ]
>Erase everything above the top "-=-=-=-" line and erase everything 
>below the bottom "-=-=-=-" line.  Do not erase anything between these 
>Indicate your TOP THREE CHOICES.
>In the brackets next to your most preferred choice, place a 1.  Place a

>2 in the brackets next to your next choice.  Continue till you use 3 
>for your last choice.  Leave other choices blank.  Start with 1, don't 
>skip any numbers, don't repeat.
>Then mail the ballot to: member-wsa-ballots@w3.org .  DO NOT SEND YOUR 
>BALLOT TO THE PUBLIC LIST.  Just Replying to this message should work, 
>but check the "To:" line.  Don't worry about spacing of the columns or 
>any quote characters (">") that your reply inserts.
>Ballots are due by the end of Thursday 13 March 2003.
>-=-=-=-=-=- Don't Delete Anything Between These Lines =-=-=-=-=-=-=-=-
>synchronous Ballot    <FB-sync> (Don't remove this marker)
>[1-3]  Choice
>[   ] geoff-1   (see definition below)
>[   ] frank-1   (see definition below)
>[   ] frank-2   (see definition below)
>[   ] dbooth-2  (see definition below)
>[   ] dbooth-1  (see definition below)
>[   ] ugo-2c    (see definition below)
>[   ] daveo-1   (see definition below)
>[   ] daveo-2   (see definition below)
>[   ] moberg-1  (see definition below)
>[   ] assaf-3   (see definition below)
>[   ] cutler-1  (see definition below)
>[   ] ferris-1  (see definition below)
>[   ] mikec-1   (see definition below)
>[   ] walden-1  (see definition below)
>[   ] assaf-1   (see definition below)
>[   ] assaf-2   (see definition below)
>-=-=-=-=-=- Don't Delete Anything Between These Lines =-=-=-=-=-=-=-=-
>Anything else may be rejected by the vote counting program. You should 
>see your vote in 
>Only one vote per person, no more than one vote per account.
>#####################  Candidate Definitions ##################### 
>Definition geoff-1 
>A message exchange pattern (MEP) is a formal description of how 
>messages are exchanged between two or more parties in support of some 
>application purpose. The pattern may define a single message sequence, 
>or may correspond to a "family" of sequences by including repeated or 
>nested sequences. An MEP is synchronous if the specification of the 
>sequence(s) includes elements in which the transmission of a message
>is dependent on either (a) the reception of some other message(s), or
>(b) coordination based on a common clock. An MEP is asynchronous if it
>includes no such dependencies.
>Definition frank-1 
>[From from Communicating Sequential Processes] Synchronous A rendezvous

>of two activities is synchronous if they complete simultaneously.
>Definition frank-2 
>Synchronous activity An activity involved in a synchronous rendezvous 
>may assume that the rendezvous is complete for both sides if it 's side

>Definition dbooth-2 
>Synchronous interaction
>An interaction is synchronous if the parties are involved in the 
>interaction at the same time and the interaction carries an expectation

>of immediate processing.  A one-way interaction is synchronous if 
>successful message delivery implies that the message either has been 
>processed by the receiver or is actively being processed.  A round-trip

>or more complex interaction is synchronous if the initiator pauses some

>of its processing to wait for the interaction's constituent messages to

>be processed. In a round-trip interaction, the request and response are

>often sent over the same communication channel.
>Definition dbooth-1 
>Property of an interaction whose results are directly following the 
>interaction. An interaction between an initiator and a respondent is 
>synchronous if the initiator blocks some further processing while it 
>waits for a corresponding action, response or acknowledgement from the 
>Definition ugo-2c 
>Asynchronous: A request/response interaction is said to be asynchronous

>when the request and response are chronologically decoupled. In other 
>words, the client agent does not have to "wait" for the response once 
>it issues the initial request. The exact meaning of "not having to 
>wait" depends on the characteristics of the client agent (including the

>transfer protocol it uses). Examples include receiving the response on 
>a different thread, on a different socket, on a different end-point, by

>polling the server, etc.
>Synchronous: The opposite of asynchronous.
>Definition daveo-1 
>a programmatic flow of control on the sender effectively does nothing 
>but wait for a response after sending it's request
>Definition daveo-2 
>the request and response flow forwards and backwards over the same 
>virtual connection between the sender and receiver.
>Definition moberg-1 
>A web service response is said to be synchronous iff it is returned 
>using the same network connection used in sending the request to which 
>it is a response. (This implies that only one URL would be needed for 
>request-response MEP when the response is synchronous and uses a 
>transfer protocol that has URLs. It also implies that the request and 
>response occur within the interval of time that the network connection 
>exists. Also, there is overhead in setting up only one TCP connection 
>when TCP is used, and since we are talking about IP _connections_ that 
>will be almost always the case.)
>A web service response is said to asynchronous iff it is returned using

>a network connection that is distinct from that used for sending the 
>request to which it is a response. (Implications: Two URLs are needed 
>to configure a request-response MEP when the response is 
>==>asynchronous. The response connection may occur while the request 
>connection is still open or after it is closed. For TCP-based transfer 
>protocols, two connection setups will be needed.)
>Definition assaf-3 
>A transport is synchronous iff the request is returned using the same 
>network connection.
>Definition cutler-1 
>Synchronous: a request/response exchange that is correlated by virtue 
>of a serialized, sequenced exchange of messages between requestor and 
>respondant, typically over the same socket or stream.
>Asynchronous: a request/response exchange that is not synchronous, 
>typically relying on some mechanism such as Message-ID within the 
>messages to correlate the request and response messages.
>Definition ferris-1 
>synchronous message exchange (applies to oneway as well as
>request/response) requires that both sender and receiver, or initiator 
>and respondant, processes are running/active at the same time as the 
>exchange takes place. In the case of request/response, the exchange is 
>synchronous if both sender and receiver remain in the running/active 
>state for both the request and response.
>asynchronous message exchange (also applies to oneway or request 
>response) does not require, but does not preclude, that both sender and

>receiver, or initiator and respondant, processes are running/active at 
>the same time as the exchange takes place. It typcally requires some 
>form of mediation between the sender and receiver such as a message 
>Definition mikec-1 
>(Taken from 
>http://whatis.techtarget.com/definition/0,,sid9_gci213080,00.html ?) In

>program-to-program communication, synchronous communication requires 
>that each end of an exchange of communication respond in turn without 
>initiating a new communication. A typical activity that might use a 
>synchronous protocol would be a transmission of files from one point to

>another. As each transmission is received, a response is returned 
>indicating success or the need to resend. Each successive transmission 
>of data requires a response to the previous transmission before a new 
>one can be initiated. Synchronous program communication is contrasted 
>with asynchronous program communication.
>Definition walden-1 
>Synchronous, then, places a constraint on a response such that the 
>response must be received within a strictly or loosely defined time 
>quantum (strict vs lax synchrony), or else the exchange fails. 
>Asynchronous differs in that no amount of elapsed time signals the 
>failure of the exchange.
>Definition assaf-1 
>An operation is synchronous if both service requester and service 
>provider engage will always engage in that operation at the same time.
>Definition assaf-2 
>An interaction is synchronous if activities demarcated by that 
>interaction will always be performed at the same time.
>David Booth
>W3C Fellow / Hewlett-Packard
>Telephone: +1.617.253.1273

David Booth
W3C Fellow / Hewlett-Packard
Telephone: +1.617.253.1273
Received on Friday, 14 March 2003 22:24:36 UTC

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