RE: [wsrm] [Fwd: Comments on WS-Reliabilty CD 0.992]

From
Jacques Durand <>
Date
2004-04-16T21:19:22+00:00
ID
Thread
RE: [wsrm] [Fwd: Comments on WS-Reliabilty CD 0.992]
Title: Message

Martin:

  
-----Original Message-----
From: Martin Chapman 
  [mailto:]
Sent: Friday, April 16, 2004 
  10:08 AM
To: 'Jacques Durand'; 'Sunil Kunisetty'; 
  
Subject: RE: [wsrm] [Fwd: Comments on 
  WS-Reliabilty CD 0.992]

  
 

  
    

    
-----Original Message-----
From: Jacques Durand 
    [mailto:] 
Sent: 15 April 2004 
    01:00
To: 'Sunil Kunisetty'; 
    
Cc: 
    
Subject: RE: [wsrm] [Fwd: Comments on 
    WS-Reliabilty CD 0.992]

    
Sunil, Martin: 
Generally agree, 
    though some comments... see inline <JD> 

    
Jacques 

    
-----Original Message----- 
From: 
    Sunil Kunisetty [mailto:] 
    
Sent: Wednesday, April 14, 2004 2:33 PM 
To:  
Cc: 
     
Subject: [wsrm] [Fwd: 
    Comments on WS-Reliabilty CD 0.992] 

    
 Few comments on the CD 0.992 draft from Martin 
    Chapman. 

    
 Tom, 

    
 Can we discuss this on the next week's call? 
    

    
 -Sunil 

    
> Only one area needs major tree surgery: section 1.7 
    should be merged with appendix II and placed in its own top level section. 
    This is the part of the doc that threw me most.

    
> 
> The rest are (minor) 
    suggestions to improve readability and comprehension. 
> 
> Line 101 - 114: editorial: delete 
    all these lines  as its castes too much doubt on the spec. 
    
> 

    
<JD> How about rewording instead like: 
    
"Reliability is often associated with QoS quantitative 
    measures, in areas other than Web services (e.g. networking). Thresholds 
    such as rate of failures, minimal size of persistent store, average latency, 
    and more generally quantitative measures that may appear in service level 
    agreements, are out of scope for this version."
 <MC> fine 
    </MC> 

    
> Line 150 - 271: editorial: I find it strange that we 
    launch into example messages without any form of introduction. 
    
> Maybe better to  insert a paragraph to explain a 
    scenario from whish these messages are derived. And also there really should 
    be an fuller explainaion of a the reliability elements.

    
> 
<JD> we have some 
    explanation at the end of each example. We could move this up 
    
before introducing each example, instead of 
    after.  

    
<mc> the text is very terse. If you look 
    at other specs they really walk though all the relevant elements and 
    explain what is going on </mc> 
[Jacques 
    Durand] Let us ask our editor, I think there was some intent to give an 
    up-front flavor of the headers, that the reader could go back to as s/he 
    progresses through the spec. (I expressed in the past my preference to see 
    these examples at the end of doc, but can understand this rationale. Now, 
    question remains how much walk through can we do up-front without much 
    knowledge of the spec...)

    
> line 358: editorial: the whole of section looks out of 
    place. It uses a lot of terminology that has not yet been introduced. It is 
    also strongly related to appendix II. I suggest moving the whole of 1.7 into 
    a new top level section after section 5 (i.e. make it a new section 6) and 
    then merge in appendix II.

    
<JD> the problem with moving the agreement definitions 
    after Sec 5, is that we refer to them 
throughout the 
    spec, starting with Sec 3, when introducing RM features. 
Why not have a new section between Sec 2 and Sec 3 (i.e. previous Sec 
    3 becomes 4, etc.) 
However, when doing so I would 
    not import the entire Appendix A/II up front, as I think 
it is unsettling for the reader who expects to get right at the core 
    features 
with as little distraction as needed... so 
    I would provide some introduction material 
on the 
    rationale for adding capability info to WSDL, and the approach recommended, 
    and 
then refer to Appendix A for the hard stuff. 
    Also if we combine the agreement and the 
  f&p stuff, clearly state that even 
    if they complement each other, they don't need each other. 

    
 

    
<mc> maybe i missed 
    something but thr agreement stuff is sort of meaningless without a way to 
    express it. Granted there may be many ways to do this, with f&p being 
    one of them. If this is what you mean then fine.
[Jacques 
    Durand] We thought this over, and  concluded that agreements 
    can remain abstract and still be meaningful here: in fact, it is the 
    only proper way to connect to "outside" agreements while keeping their 
    representation open. We describe our RM features like: "if 
    <agreement-item-XYZ> is enabled (or has value ABC), then the message 
    protocol must look like this, the behavior must be like that." 
    Just describing the 
    protocol on teh wire was ignoring the agreement aspect. Also, some features 
    like resending messages (and related parameters, like # of retries, etc) 
    would not even appear in the message protocol. We needed to be able to talk 
    about the behavior they cause even if they don't have a concrete 
    representation.

    
Generally though, the 
    agreement stuff is very detailed, and the detail is launched into without 
    any overview of rationale.This is my main conecern so even putting that in 
    its own section may not help. </mc>
[Jacques Durand] Agree. Will propose 
    something. 

    
 > 
    
> line 444: editorial: I suggest adding a paragraph or 
    two here that does provide a very high overview of the model. The 
    subsequenst sub section dive into details without giving the reader an 
    overview on which to elaborate. I suggest using the text in the pre-Tc 
    version that was published:

    
> 
> "In the Reliable Messaging 
    Model described in this document, the sender node sends a 
> message to the receiver node directly (i.e., intermediaries are 
    assumed to be 
> transparent in this 
    specification). The receiver node sends back an Acknowledgment 
    
> message to the sender node. Figure 1 shows this 
    model. 
> Figure 1 Messaging Model" 
    
> 
> This should provide 
    enough context 
> 
<JD> Isn't that very similar to the first bullet item of 2.1 ? 
    
No problem with this rewording though. 
    
But the transition to 2.2 (and Figure 1) probably 
    calls for another sentence like: 
" the basic 
    exchange patterns described in 2.2 derive from the above messaging 
    assumptions. 
Reliability features defined in this 
    specification will in turn rely on these patterns."  

    
<mc> fine </mc> 
> 
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