[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: RE: [soa-rm] David Linthicum Says: "ESB versus Fabric.Stop It!"
[scroll down please] > -----Original Message----- > From: Duane Nickull [mailto:dnickull@adobe.com] > Sent: Wednesday, May 25, 2005 2:05 PM > To: McGregor.Wesley@tbs-sct.gc.ca > Cc: soa-rm@lists.oasis-open.org > Subject: Re: [soa-rm] David Linthicum Says: "ESB versus > Fabric.Stop It!" > > > > McGregor.Wesley@tbs-sct.gc.ca wrote: > > >Perhaps a new metadata tag such as "aggregation" is more appropriate? > > > > > > > Wes: > > Can I ask you what would make a single service care that the > consumer is invoking it as part of an orchestration? Why > should the service care. > It's function is simply to facilitate the invocation request. > If someone created a dependency on the service to know about > the state of other service invocation requests, that would be > very bad architecture IMO and also violate the principles of > autonomicity (not really an English word but you get the idea). > > Individual services MAY have to be architectued to have the > specific capabilities required by such infrastructures > (example - a two phased commit vs. a single phase) to account > for the fact a service request may only be committed if other > services are successfully completed. Once again however, I > do not see that the service has to know the state of the > other service - all such coordination is done as a higher > level application. > > I will propose that we accept this axiom: > > "Services should not have to have explicit knowledge of the > states of other services called by a consumer that invokes them" > > Does anyone disagree with that? The idea is that the > coordination of states of multiple service calls is > coordinated at a higher level. Each service is only the > "slave" in a "master - slave" relationship. Completely agree with this axiom. I also recommend that we explain it in the terms in your paragraph just above, even mentioning the two-phased commit notion you describe earlier, and also the "O" word (orchestration). I believe this will make our points even clearer. Joe Joseph Chiusano Booz Allen Hamilton Visit us online@ http://www.boozallen.com > Duane > >
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]