"I have a mind like a steel... uh... thingy." Patrick Logan's weblog.

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Saturday, October 23, 2004

Principled Design

Roy Fielding writes...

Software development is still driven by fads and fashion. In order to become well known, you need to hire some sexy models and generate press. Personally, I'd rather that people just learn a little more about software architecture and principled design.

Who Cares?

S. Mike Dierken in the rest-discuss Yahoo group...

I've only met two or three people that understand - much less care deeply - about REST. I have met people that quickly recognize the value when I explain the basics, though. Amazon is full of very smart & quick people.
Put me in that latter category. Not that I am very smart or quick, but I recognize the value of the basics. I still get lost in the details when even the people who care deeply debate them.

I like this from Roy Fielding, which may be enough for me...

In short, if you can draw a state machine in which each state is self-described (resident on the client), the transitions from that state are also self-described (instructions for the client to initiate), and each transition is invoked using a self-descriptive message, then you have a RESTful application. All of the rest of the constraints fall out from the need to be self-descriptive...

Note, however, that it isn't necessary for all components to understand all of the semantics. It is only necessary for them to know when they do understand them and also when they do not. That way, applications can be deployed within the subset of the network that does understand without adversely impacting the components that do not (assuming they are implemented according to the communication standards).

And then there's this follow-up from Dave Pawson...
Following this most recent thread makes grabbing eels look easy.

Friday, October 22, 2004

Another Kind of Scaling

Joel captures the anti-institutional aspect of Web 2.0, although he hasn't expressed it this way.

First, Joel on Microsoft...

If I were Bill (Gates), I think I'd fire about three quarters of the people working on that (the presentation system). Not because they are incompetent. But because there are too many people creating too many technologies.
Compare with the Web 2.0 paradigm, e.g. Basecamp...
Aren’t big payrolls and large head counts Web 1.0?
Back to Joel, this time on Google...
One of the mistakes Google is making is applications like Gmail are great on the Google platform. But if Google was really paying attention, they'd say we have to have outside developers writing applications for Google. There should be 27 different e-mail systems using the Google infrastructure.
And finally, Joel on other Web 1.0 institutions...
Nobody's ever going to use SharePoint in college. Ever. So no startup is ever going to use SharePoint because none of the kids who leave college are going to know it. This was BEA's big problem. Kids in college, when they want to learn about Web development, they learn Perl, PHP, maybe Microsoft's (ASP.Net) stack. They don't learn about Domino or BEA...

It's weird Microsoft doesn't recognize this with things like SharePoint and InfoPath. .. the only way those guys [BEA, MSFT, etc.] have hope of getting mind share in the market is to have an extensive sales force.

Half Mast

The computing flag is at half mast. Ken Iverson has died at the age of 83.

As the inventor of APL, Iverson was truly one of just a handful of original thinkers of programming.

Thursday, October 21, 2004

The Syntax and Semantics of Coordination

Don Box...

To anticipate Patrick's comments, I'm a huge fan of minimal kernels of abstraction (like lisp) upon which we define entire universes.

SOAP is minimalistic enough for me - it's sad (but not terminal) that SOAP's defun, WSDL/XSD, is as complicated as it is.

Had we started with a simpler basis (perhaps Relax NG + some SOAP-specific extensions), my guess is we'd be having different discussions right now.

This seems to be arguing about syntax, more or less. I think the more interesting argument is about semantics. In particular, the semantics of coordination.

Looking for a minimal *coordination* kernel (a machine) upon which we define entire *coordinated* universes, SOAP is merely a syntax for defining the right machine primitives. SOAP is a general purpose *language* kernel. We still need to define the machine kernel, whether we use SOAP or something other language to describe it.

What would make a good coordination machine kernel?

It should have enough primitives to be useful for the simplest cases. Those primitives should be fixed and yet composable for most of the interesting, complex cases.


The rest-discuss Yahoo group is in the midst of a useful discussion of what makes for RESTful uses of HTTP POST. Roy Fielding's description of a RESTful client-based state machine was a point in the conversation that I could latch on to.

From there I was able to go back and forth through the chronology of messages to piece together the points of discussion. Mark Baker's arguing for a more strict definition of RESTful POST (I think) than Roy, but I'm not sure yet whether this is a communication issue or a technical issue with HTTP itself.

IBM and Smalltalk, Dynamic Languages

Is IBM blowing their Smalltalk ship out of the water just when the tide is heading again for dynamic languages?

Sunday, October 17, 2004


A creative mosaic memorial.

I am not an economist...

...so this could either concern me or lull me to sleep...

The Chinese currency is currently overheated, with inflation there approaching double-digit levels and threatening to lead to economic collapse. Prevailing view is that if China doesn't immediately revalue its currency upwards by 20-25% (so much for the benefits of offshoring!), it will suffer a hard correction and severe recession. The consequences of that will be a sharp, inflationary increase in the cost of Chinese goods, and great difficulties for the many, many American companies that are now utterly dependent on cheap Chinese goods for their survival. Thanks, Wal-Mart!

Who'da thunk it?

Cornell University News...

According to a new Cornell University study, Bush's approval rating rises every time the federal government issues a new terrorist warning, by an average margin of 2.75 points.

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Portland, Oregon, United States
I'm usually writing from my favorite location on the planet, the pacific northwest of the u.s. I write for myself only and unless otherwise specified my posts here should not be taken as representing an official position of my employer. Contact me at my gee mail account, username patrickdlogan.