Business services responsible for their SLA may have difficulty living up to those promises without taking into account where their data lives, what its availability is, and what kind of performance can be expected from it. All these factors are critical in making decisions about things like what to cache, for how long, as well as how to communicate out data accuracy/staleness expectations to stakeholders.
For example, when looking at information provided by companies *like* ETrade, the staleness is communicated up front - prices correct to 15 minutes ago. If consumers want more up to date data, they need to pay, but it only starts there. The architecture and technology under the more up to date user experience is different. Does that make sense? -- Udi Dahan * None of this should be taken as a statement to how ETrade systems actually work. From: [email protected] [mailto:[email protected]] On Behalf Of Gregg Wonderly Sent: Tuesday, April 14, 2009 1:18 AM To: [email protected] Subject: Re: [service-orientated-architecture] Joe on Microsoft's combination of SOA & Storage Michael Poulin wrote: > I still think that data storage should be outside of SOA scope: business > services do not care where data comes from whilst the data is of good > quality. I think this is an interesting opening to some more discussion of what matters in what you call SOA and what doesn't. Data storage has an important aspect to it, and that is the storage technology and the retrieval technology. When you include technology, there is an interface involved, and that interface is important to the overall usability. For example, let's say we have three nice middle aged adults in your business that are responsible for data storage. If they decide that they want to keep everything printed on paper, and anytime you need data, you have to find one of them, have them look through the 3 rooms of file cabinets to find what you need, and then transcribe it into the format that you need it, would that be just as acceptable to you as a database system access using ONLY oracle PSQL, or just as acceptable as an HTTP based service? What if there core of your SOA was CORBA, JMS or Jini based? Would you still "consider" data storage to be "outside of SOA scope"? More directly, how would you decide what was acceptable performance of your system if the data storage decision didn't play into the architecture portion of your SOA? Gregg Wonderly
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