Re: [soa-rm-ra] Follow-up to 7-5-08 Telecom

[Francis McCabe <frankmccabe@mac.com>]

Michael:
  About this:

On May 11, 2008, at 8:25 AM, michael.poulin@uk.fid-intl.com wrote:

> 1887 A Message denotes either an action or an event. In other words,  
> both actions and events are realized
> 1888 through messages.
>
> To me, the last sentence is incorrect. Both actions and events may  
> be not REALIZED through messages but INITIATED; the actions and  
> events are realized through the service only.  If accept that  
> actions and events are realized through the message, the service MAY  
> NOT do anything that is not visible through the messages, which is  
> far from reality. The real world effect may be totally invisible  
> through the service messages and interface. Limiting realisation by  
> communication messages is a pure Web Service mentality.  Here is  
> another real-life example.


You will meet a lot of resistance from me on this point. There are  
actions and events. These are, as you have observed, connected to RWE:  
an action leads to a RWE and a RWE is reported as events. In a message  
oriented system, we can use messages to denote both actions and  
events: from the perspective of a participant, sending a message with  
an action 'embedded in it' counts as, is the same as, performing the  
action: that *is* how a participant performs actions in a distributed  
environment.

This is an important point, for example in auditing repudiation:  
sending a message to open an account *is* the same thing as trying to  
open the account: you may be legally liable for the consequences of  
doing so.

The other shoe, so to speak, is that not all actions are successful,  
not all actions have the desired result. Pushing a lever does not turn  
the machine on if it is broken or locked. Again, there is no  
substantial difference in this whether you use messages to denote  
actions or levers: from the perspective of a participant (especially a  
software agent), it is immaterial whether a software library call is  
implemented as a message or as a call to turn a motor on.

Frank