See inline
 
----- Original Message ---- 
 
[SJ] From the perspective of the consumer and the service they don't care 
 what happens in between just that it happens.   How is REST 
 fundamentally different from the perspective of A and B when I don't 
 want EITHER of those caring about the execution context that is in 
 use?  I want developer at A to "discover" the service description of B 
 and write B.C and for everything else just to happen.  I want B to 
 write their service and for something to expose that service to the 
 internet/intranet/ project/etc 
  
 This is why I think its a pointless argument, we are arguing about the 
 best execution context.  We are the golgafrinchans. 
  
[SC]  If you're purely focused on the delivery-model aspects of 
services-oriented development, in terms of reducing lead times and deliverable 
sizes, then perhaps the architectual style is pointless.  This becomes really 
about balance of power and governance issues, then.

I think the second side of the SOA coin is the network effects from autonomy 
and loose coupling -- which potentiall reduce the marginal costs of integration 
to zero.

Your example strikes me as classic RPC-based development, and focused on the 
individual developer rather than on the  network application itself.  It really 
doesn't illustrate any incremental benefit compared to what we've been doing 
for 10 years now in CORBA or EAI.


[SJ] Or how REST pushes more systems comprehension back onto the consumer. 
 NONE of these approaches get away from the basic point that consumer A 
 wants to call capability C on Service B.  They are all JUST examples 
 of execution context implementation, and the execution context adds 
 ZERO value to the interaction. 
  
[SC]  REST has a very different way of describing capability "C" than CORBA, 
DCOM, or DCE... 

C is split into
- what operations I have
- what data types are required
- how do I refer to C on service B
- how do I describe the required data types

The point is that these descriptions of capability C should be shareable across 
any service producer and consumer -- even those that never new that service B 
existed, or else every integrated endpoint costs labour $$$.

I've seen approaches come close to this (RMI was close) but never across 
platforms, languages, etc., except in the case of the web.

[SJ] We need to move on from these debates and start worring about A and B, 
 rather than believing that the technology in the middle actually 
 matters. 
  
[SC] I think the focus definitely should be on contracts and shared data 
semantics, sure.   But the rubber does have to meet the road somewhere.   IT 
and computing isn't JUST about people, politics, economics & semantics, it's 
also computer science --  and most people are poor at both.

If your goal is to reduce the marginal cost of integration to "near zero", 
there are some architectural styles (and their technologies) that have 
constraints that will lead to more success when building such contracts than if 
you use a style with fewer constraints.  That's why these arguments are not 
pointless.

Cheers
Stu






------------------------ Yahoo! Groups Sponsor --------------------~--> 
Great things are happening at Yahoo! Groups.  See the new email design.
http://us.click.yahoo.com/TISQkA/hOaOAA/yQLSAA/NhFolB/TM
--------------------------------------------------------------------~-> 

 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/service-orientated-architecture/

<*> To unsubscribe from this group, send an email to:
    [EMAIL PROTECTED]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply via email to