Re: granularity/definition of a "service"

here my 2 cents 

> The BPEL4WS specifies 
> these and other control constructs as "Activity". So in this context
> is a "service" at a higher level of abstraction  then an "Activity" 
> or do they have equivalent semantics. 

my take on it is as follows:
- a service consists of a collection of (probably related) operations
- BPEL constructs like "invoke" or "receive" refer to such *operations* 
(not to the service as a whole)

BTW, the discussion of service granularity reminds me on similar 
discussions in the J2EE world, where Enterprise Java Beans had to be 
designed more coarsely grained than usual Java beans, in order to reduce 
costs of network traffic (=> leading to Façade design pattern, Value 
Object pattern, Local interfaces in EJB 2.0, etc.). A fine grained EJB is 
still a valid EJB, even if not a very well designed one. I would assume 
the same applies to services.

However i have never seen a formal treatment of the topic, so it would be 
indeed interesting to learn more about the issue.

regards,
Joachim

Received on Thursday, 16 September 2004 12:44:48 UTC