Re: [soa-rm] Service Consumer in RM or not?

[Francis McCabe <fgm@fla.fujitsu.com>]

I always understood the issue to be one of modeling versus  
conceptualization.

What concepts are required in order to be able to talk effectively  
about an SOA? Those concepts belong in the RM.

However, as I have previously said, when you want to talk about  
agents communicating, you can either focus on the agents, or on the  
conversation. The former approach emphasizes things like agents,  
messages, and so on. The latter emphasizes what a legal conversation  
looks like -- and does not focus on the agents themselves.

In a service oriented world, we have a similar choice: we can focus  
on the participants or on the service. A focus on participants leads  
to things like messaging, service providers, service consumers etc. A  
focus on service leads to things like action, policy, semantics.

It is not that there are no service providers or consumers, but that  
the focus is elsewhere.

Frank

On Jun 7, 2005, at 5:42 AM, Chiusano Joseph wrote:

> Matt and Duane,
>
> I completely understand your concerns as stated below. Is there  
> perhaps a middle ground, where we can constrain expansion into  
> architecture? Do comsumers have to be viewed as "endpoints"? Or can  
> they be viewed as "actors"? If so, does that change any perspective?
>
> If this does not make sense (in terms of not making sense to  
> include service consumers in the RM), and we include them in an RA,  
> I hope we can leave open the possibility that this TC's outputs can  
> potentially be labeled as:
>
> - A Service Orientation Reference Model (SO RM) - that is, don't  
> label this as "SOA RM" but rather "SO RM"
> - A SOA Reference Architecture (SOA RA)
>
> rather than a single SOA Reference Model (SOA RM).
>
> Joe
>
> Joseph Chiusano
> Booz Allen Hamilton
> Visit us online@ http://www.boozallen.com
>
>
> From: Matthew MacKenzie [mailto:mattm@adobe.com]
> Sent: Tuesday, June 07, 2005 8:14 AM
> To: SOA-RM
> Subject: Re: [soa-rm] Service Consumer in RM or not?
>
> If I can interject...
>
> I think that Duane and I are concerned with the slippery slope that  
> exists when we start including endpoints such as consumers in the  
> RM.  After consumers will come messages, and the next thing we know  
> we'll have a WSDL binding in appendix e or some such.
>
>
> arrrrgggghhhh!!!
>
> :-)
>
> -matt
>
> On 7-Jun-05, at 7:21 AM, Chiusano Joseph wrote:
>
>> <Quote>
>> If we do vote to include the SC, we then have to open up the RM to  
>> everything else that follows which means that it won't be a RM, it  
>> will be     architecture.
>> </Quote>
>>
>> Duane,
>>
>> This is an idea that I see you have been pushing very hard almost  
>> from the start of our TC, yet I believe some of us are perplexed  
>> as to why introduction of a service consumer into an RM is against  
>> the notion of RM. Can you please clarify for us?
>>
>> Thanks,
>> Joe
>>
>> From: Duane Nickull [mailto:dnickull@adobe.com]
>> Sent: Mon 6/6/2005 7:39 PM
>> To: peter@justbrown.net
>> Cc: 'SOA-RM'
>> Subject: Re: [soa-rm] Service Consumer in RM or not?
>>
>> Hi - I'm back!!
>>
>> Comments inline:
>>
>> Peter F Brown wrote:
>>
>> >1) A service is an event
>> >
>> DN - a "service invocation" is an event. The "service" itself is  
>> not an
>> event IMO, it is an invoke able entity..
>>
>> >representing a collaboration between two parties
>> >for the use of defined resources: a "service RM" would be  
>> concerned with
>> >representing both parties (provider and consumer), the duality of  
>> their
>> >interaction through the event and the use of resources...
>> >In this approach:
>> >- service consumer would definitely be in, as one side of the  
>> event-based
>> >duality (provider<>consumer);
>> >- a further level of abstraction can be modelled, that of  
>> "agent", to
>> >highlight the shared properties of both provider and consumer. In  
>> this
>> >manner, it would be easier to answer the problem "how do we model  
>> the
>> >situation where a service provider can also be a consumer, and  
>> vice-versa?".
>> >They are both agents. Whether they are consumers or providers would
>> >therefore be modelled as a "role" in agent.
>> >
>> >2) A service is a "directed collaboration" between two parties:  
>> directed in
>> >the sense that one party provides a service to another: a  
>> "service provision
>> >RM" would only be concerned with one side of the duality,  
>> representing the
>> >service provider, irrespective of whether the service is used, or  
>> whether
>> >there is a consumer at the end of the "pipe"...
>> >
>> >
>> I would like to call for a vote on this too to put it to bed for  
>> once an
>> all.  My assertion = If I architect something with a service, a  
>> consumer
>> does not have to be present for it to be "service oriented".   Nor do
>> messages, networks, signals, pings, security, encryption etc  
>> etc.   This
>> is much the same as stating that a "message" does not have to be  
>> sent in
>> order for it to be a "message".  It can exist with or without being
>> transmitted.
>>
>> If we do go the way of the service provider and service consumer,  
>> this
>> could be done in an illustrative (non-normative) manner in the RM or
>> (and I favor this idea) as part of a reference architecture.  If  
>> we do
>> vote to include the SC, we then have to open up the RM to everything
>> else that follows which means that it won't be a RM, it will be
>> architecture.
>>
>> I had hoped we could gain consensus on this and avoid a vote  
>> however I
>> feel a vote may be inevitable.
>>
>> BTW - has anyone else noticed that the list is very slow today? It  
>> took
>> 5 hours for my last message to come back to me via this list?
>>
>> Duane
>>
>