Actually, it cannot. If it is not an external consumer, it is an external process calls for the service (Scheduler, autosys, Calendar, whatever). Service serves upon a request. It is only waiters in the low- quality restaurants ask you 'is everything OK?' every 10 minutes...
However, request:response != 1:1, it may be 1:M (call-back, subscription, etc.) - Michael ________________________________ From: Udi Dahan <[email protected]> To: [email protected] Sent: Wednesday, December 24, 2008 9:42:37 PM Subject: RE: [service-orientated-architecture] Re: Yefim Natis is sure that "SOA is integration" Could not a service run periodically, without any external calls? -- Udi Dahan - The Software Simplist From:service-orientated- architecture@ yahoogroups. com [mailto:service- orientated- architecture@ yahoogroups. com] On Behalf Of Michael Poulin Sent: 23 December 2008 11:50 To: service-orientated- architecture@ yahoogroups. com Subject: Re: [service-orientated -architecture] Re: Yefim Natis is sure that "SOA is integration" Here is a misunderstanding, Rob. Certainly, to run, a service needs an external call. However, self-contained atomic SOA business service does not need any other business services to provide its RWE; it does not know about outside world of services. In contrast, an aggregate service - does. - Michael ________________________________ From:Rob Eamon <rea...@cableone. net> To: service-orientated- architecture@ yahoogroups. com Sent: Tuesday, December 23, 2008 4:01:52 AM Subject: [service-orientated -architecture] Re: Yefim Natis is sure that "SOA is integration" --- In service-orientated- architecture@ yahoogroups. com, Michael Poulin <m3pou...@.. .> wrote: > > Integration with what? > > Assume, we have a self-contained atomic SOA business service. It > does not need anything outside its boundaries to perform announced > business functionality and provide for the RWE. Oh yes it does. A service all by itself does nothing. Without some external stimulus, it does nothing at all. Something outside of the service must call it via one of the exposed interfaces or the service will do nothing whatsoever. > Certainly, it has to run in an execution environment and it > integrates with it. However, it does not integrate with an > orchestration or a process that uses it because it perfectly > functions alone. The orchestration or process integrates with the service by connecting to and invoking one of the service's exposed interfaces. > Invocation of such service does not generate any new business value. Invocation of a service is required to generate any busines value. A service uninvoked is a useless pile of bits. > As I responded to Rob, if a SOA service does not have an interface > for particular type of communication channel, does it " have > intrinsic seamless integration capabilities" ? No. But then how did the architect miss that channel? But for the channels/interfaces that are not missing, the system has intrinsic integration capabilities. > So, integration is just a link system between participants (may be > one link for 2 participants) . Connecting those participants we do > not create a SOA system, or we do? Connecting participants creates an integration. Creating an "SOA system" (a term I loathe) requires creating service providers with separately standing interfaces that are invoked within an execution context by service consumers. Consumers integrate with providers via the agreed upon interfaces. -Rob No virus found in this incoming message. Checked by AVG - http://www.avg. com Version: 8.0.176 / Virus Database: 270.10.0/1861 - Release Date: 22/12/2008 11:23
