Bear in mind that I am not at all technical. The notes I made on this are pointless, because it was like I was transcribing phonetically the incomprehensible squawks of someone speaking in Swahili. Now imagine, on the Friday before Memorial Day weekend, over a hundred engineers, plus me, sitting in a hot room listening to a self-professed "data weenie" (ha. ha.) discuss service-oriented architecture.
The word service is being used for 'Not Sharing Transactions'--they are wary about their borders. When talking about services, we should assume that System A and System B can't make atomic transactions.
operators and operands--can't really follow this.
transactions & seriability--ditto.
"transactions live in the now"
"unlocked data allows change"
"messages are from the past, not the now"
something about simultaneity--slide moved away too fast
"operands live in the past and the future" (umm, okay...)
"everything between service lies in the past or future, not now"--now is only inside a services. so it's not meaningful to speak of the now between services; there is no simultaneity; each service has its own notion of "now". Services have to make the now meet the then, and fix this problem. The business logic of each service has to reconcile that.
Once messages are sent you can't unsend them. You can send corrective ones, but it's not the same message.
something about schema--not clear how schema fits in
DAGs of history--no idea what this is
"optimistic concurrency control"--paraphrase: "I knew this is what the info used to be and I'd like it to be this now, trust me!" But service-orientation is not about trust, it's about autonomy. Local business logic decides validity of data and whether or not we're going to change it. The other service has to "ask nicely" which I guess means a proper message. Business operations can't be direct hacks into the db.
When we get a message we can shred for data but we should log original static version of the message.
A slide on XML, SQL, and Objects that was incomprehensible in its significance.
Bounded and Unbounded Data Representations: relational is bounded; xml-infoset is unbounded. relational is within the now of a database; whereas unbounced xml info is interpretable everywhere. "infoset" is the semantics of an xml document.
Services as black boxes.
Does it look from my notes as if I actually understood even the tiniest particle of that? You'd be wrong. Tragically wrong. The whole freaking lecture was a black box. My god I want to go home now. *weep*
I'm not really weeping. Though this morning I was cheerier, and jotted down for an LJ post that never quite was: "Meanwhile, it's gorgeous outside in Seattle. I had a raspberry and cream cheese crumpet for breakfast. My head is full of bees."