RE: [ebxml-msg] Groups - Multi-hop Section Draft 0.18 (ebMS3-Multihop V18-Nov07.doc) uploaded

From
Durand, Jacques R. <>
Date
2008-11-19T04:25:43+00:00
ID
Thread
RE: [ebxml-msg] Groups - Multi-hop Section Draft 0.18 (ebMS3-Multihop V18-Nov07.doc) uploaded
inline 

 

-Jacques

From: Sander Fieten 
[mailto:] 
Sent: Tuesday, November 18, 2008 12:12 
AM
To: 
Cc: 

Subject: Re: [ebxml-msg] Groups - 
Multi-hop Section Draft 0.18 (ebMS3-Multihop V18-Nov07.doc) 
uploaded

Jacques, 

here are my remarks up to section 1.7.1. 

Regards,

Sander

line 13: 

The new role for MSH's is introduced here and called "intermediairy". There 
is also a reference to the already existing roles in the core spec, which are 
"Sending" and "Receiving".     On line 285 where the Intermediary role 
is further defined the new messaging function is called "Forwarding". Wouldn't 
it be more appropiate to use this term on line 13 when the intermediary is 
introduced because an intermediary is an MSH that implements the "forwarding" 
function? 

 

OK 

line 32:

says about endpoint MSH: "it is in general only compliant with the Core 
ebMS V3 specification". Because of the WS-A requirements that the multi-hop 
situation imposes on the endpoints this statement might be too strong as there's 
no need for WS-A support in an MSH to be able to comply with the core 
spec. 

 

OK

 

lines 31-32 and 36-37:

"A multi-hop topology usually comprises Endpoint MSHs on its periphery, 
although it does not have to: for example, in a ring topology all MSHs are 
Intermediaries." looks inconsistent with "An Endpoint MSH can not act as an 
Intermediary MSH" on lines 31-32. 

O K 

Section 1.3.1 (lines 43-63):

Are all these assumptions critical to define the topologies of sections 
1.3.2 - 1.3.4 ? As far I can judge only the first assumption is important as the 
topologies only consider ebMS MSH's, i.e. nodes that act on the headers defined 
in this spec or the core spec. I propose to just have an overview of the [main] 
topologies and move the assumptions to section 1.4.1.  

 

modified 1.3.1 and put it at the end of 1.3. Should not be in 1.4 because 
these assumptions are not all requirements. May be just there for convenience of 
the specification. 

line 49: 

The text now states that other types of intermediaries like SOAP 
intermediaries and http proxies are not required to understand the ebMS headers. 
But what about the WS-A headers that are required by this specification? 
Shouldn't it be more general that other intermediairies are intermediaries that 
do not act on the headers as defined in this specification? This could be done 
by changing "they are not required to understand any of the ebMS headers" to 
"they are not required to understand any of the ebMS meta data available in the 
headers and are not supposed to act on this data." 

 

OK 

line 55-56:

I'm not sure about the meaning of this sentence. I assume this means that 
intermediaries may support pulling by endpoints, right?

 

removed

line 59-62:

From this assumption I understand that one MSH can act both as an 
intermediary and endpoint MSH. This conflicts with the statement on line 31-32 
that "An Endpoint MSH can not act as an Intermediary MSH". I think there might 
be use cases where one would like to have an MSH act in both roles, but I'm not 
sure if the current text allows this.  

 

fixed

 

 The distinction between P-Mode 
and routing function make it complex to both roles integrated into one MSH, at 
least when accessed through one address.

 

I 
tried to nuance this distinction in update on 1.5.1.

Sections 1.3.2 - 1.3.4 (lines 64-85) :

In these sections addressability is a much used term without a clear 
definition of what that is. I think here addressability is meant whether the MSH 
has a publicly known static (is this required to be static?) IP-address or 
hostname and not about the possibility to identify the endpoint on the ebMS 
level using the meta data available in the message header.

 

removed.

Section 1.4.2:

I think addressability should be defined explicitly i.e., that it defines 
the addressability on the transport layer and not the ebMS layer. The endpoint 
is addressable by the meta data available in the message header, but might not 
be addressable by an IP address or hostname.  

 

added 
a definition in 1.4.2 

line 108:

I think "This implies that Intermediaries do not modify ebMS messages" 
should be "This implies that Intermediaries do not modify messages" as 
intermediaries shouldn't change any message that is part of a end-to-end 
conversation.

 

OK

line 120:

It looks there're some words missing after "and some subset of PModes may 
need be configured on"

 

fixed

line 176:

I propose to talk about endpoints here like: "Edge hops: 
controlled by PMode deployed on the connected endpoint MSH"

 

OK

line 177:

Does (part of) the PMode have to be deployed on the intermediary? Shouldn't 
the required info not be part of the result of the routing function or is this 
what you meant here?

 

removed.

 

line 228:

"This edge-binding applies when both Sender and Receiver endpoints are not 
addressable". This case can also apply to an addressable Sender.

 

fixed.

 

Section 1.5.2.2

The pulling from the Sender as described here also seems to require pulling 
by the Receiver because the intermediaries do not generate PullRequest signals. 
As noted at the end of the sections it is however possible to only pull on the 
Sender edge hop and use push on the received edge hop. To make this possibility 
more explicit I propose to use this situation as case 4. 

 

In described case 4, Intermediaries can be configured to generate 
PullRequest signals: this is part of a forwarding mode... The only thnig they never generate, are User Messages (and 
eb:Receipts). They also can generate eb:Error 
meessages.

Adding 
a Case 5 for what you describe above.

Section 1.5.3.1

Also mention the [common] case where the Sender endpoint uses MEP binding 
"Two-way / Push-and-Push" and the Responder "Two-way / Pull-and-Push" ?

 

Added 
mention of the case.

 

line 356:

In "... and will pull the reply message over the same ..." 
I propose to change "pull" to "get" to prevent confusion with pulling 
messages. 

 

OK

Would it be usefull to add a remark on end-to-end synchronous 
communication, like this:

"Although both endpoints in this case use synchronous communication with 
their respective intermediaries there is no guarantee that the response message 
is communicated synchronously end-to-end as the I-Cloud hops might use 
asynchronous communication. When an I-Cloud uses synchronous communication on 
the I-Cloud hops to enable end-to-end synchronous communication this may be very 
resource intensive on the intermediaries because of all open connections."

 

OK

line 526:

I propose to use "Initiating Message" instead of "Request Message". In a 
two-way MEP the request message is the first ebMS user message sent, but here it 
is just the first message. Therefore I think it is better to use initiating 
message instead of request message.

 

OK

On Nov 11, 2008, at 1:10 ,  wrote:

  
V0.18:
- remodeling of section 1.5, especially 1.5.2 and 1.5.3, with 
  missing cases
and new figures.
- some figures migrated from 1.5 to 
  1.6
-section 1.7 on endpoint requirements, reorganized, with an addition on 
  how
to interpret wsa:ReplyTo (1.7.3).
- edits in 1.8, with main addition 
  1.8.3 on how to control other aspects of
multihop edges binding (not 
  complete yet)
- also see the proposed introduction of the "I-Cloud" IRI for 
  use in wsa
EPRs, i.e. when the destination URL is unknown, such an IRI 
  would be used
to indicate that routing must rely on ref 
  parameters.

-- Mr Jacques Durand

The document revision named 
  Multi-hop Section Draft 0.18 (ebMS3-Multihop
V18-Nov07.doc) has been 
  submitted by Mr Jacques Durand to the OASIS ebXML
Messaging Services TC 
  document repository.  This document is revision #16
of 
  ebMS3-Multihop.doc.

Document Description:
Draft of the multi-hop 
  section.
V0.3:
- a few updates in the definition section 
  (editorial)
- added a commented Flow diagram (section 1.7.1) on RM 
  sequence
establishment. To review.
V0.4:
- section 1.5 (Intermediary 
  Role) rewritten, though not complete yet.
(diff with 0.3 
  visible)
V0,5:
- section 1.5 updated based on feedback and extended for 
  response
messages.
V0.14:
- Section 1.5 redefines multihop MEPs in 
  terms of first hop + last hop. It
does not include the routing inside the 
  I-Cloud which is relevant to the
routing function.
- Section 1.5.4: Two 
  options for multi-hop pulling ... and probably one too
many.... Need to 
  define multihop pulling.
- Section 1.6.3 on routing function has been 
  edited.
- Section 1.8 on PModes has been deeply redesigned based on what 
  was said
prior

V0.6:
- Added text to section 1.5 on streaming and 
  store-and-forward models for
implementing intermediaries
V0.7:
- 
  Changed the text describing the streaming model to include two sub 
  cases,
asynchronous and synchronous streaming.
V0.8:
- a few updates 
  / corrections (diffs visible)
- fleshed out the &quot;routing of 
  Acks&quot; multihop subsection at the
end.
V0.9:
- Updated 
  definition of routing function and mep bridging
- Changes to section on 
  details of the routing function. The changes here
are mostly textual. 
  Changes shouldn't have impact on spec itself.
V0.10:
- Moved section 
  1.4.3 Endpoints requirements to 1.6 where requirements can
be more 
  explicitly formulated
- Reformatted handling of routing input by 
  intermediary
- New section 1.6 on Endpoints requirements, includes 
  introduction of
RefParam PMode feature
- Added section 1.7 to specify 
  definition of WS-A reference parameter
V0.11:
- Added text to section 
  1.4.6 on specific MEP bindings for multi-hop
V0.12:
- added missing flow 
  diagrams (not yet fully comented)
- inserted text for Section 1.8.
- 
  added several comments ([jacques]) and complement text (diffs 
  visible)
V0.13:
- more complete draft of the MEP section 1.5, with 
  multihop channel
bindings.
- added a new section on PModes for multihop 
  (1.8)
- minor changes in 1.7
- expanded on the Error handling section 
  (1.4.5)
V0.15:
- Section 1.5 redefines multihop MEPs in terms of first 
  hop + last hop. It
does not include the routing inside the I-Cloud which is 
  relevant to the
routing function.
- Section 1.5.4: Two options for 
  multi-hop pulling ... and probably one too
many.... Need to define multihop 
  pulling.
- Section 1.6.3 on routing function has been edited.
- Section 
  1.8 on PModes has been deeply redesigned based on what was 
  said
prior
V0.16:
- more complete section 1.8
- figures added in 
  MEP section, explicit model separating ICloud hops 
  from
&quot;peripheral hops&quot;.
V0.17:
- sharpening of 
  terminology in earlier sections
- Section 1.5 largely rewritten, with 
  updated figures (for terminology)
- still some clean-up to do in 1.5 and 
  also 1.8
V0.18:
- remodeling of section 1.5, especially 1.5.2 and 1.5.3, 
  with missing cases
and new figures.
- some figures migrated from 1.5 to 
  1.6
-section 1.7 on endpoint requirements, reorganized, with an addition on 
  how
to interpret wsa:ReplyTo (1.7.3).
- edits in 1.8, with main addition 
  1.8.3 on how to control other aspects of
multihop edges binding (not 
  complete yet)

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http://www.oasis-open.org/committees/document.php?document_id=29971

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