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

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Friday, February 24, 2006

Stasis

Alan Kay paraphrased by Phil Windley...

The future five years out is easy to predict because all of the forces acting on computer science are trying to keep it the same as it is now...

Architecture demands arches...

[People's] stories are inconsistent with what they know, yet they persist in believing them, even though they have the knowledge that contradicts their theory.

When people react instantly, they’re not thinking, they’re doing a table lookup...

To do creative work in computing, you must get past what you think is normal. Write down the 20 things you think are true of computing and try to demolish them...

Most people who graduate with CS degrees don’t understand the significance of Lisp. Lisp is the most important idea in computer science. Alan’s breakthrough in object oriented programming, wasn’t objects, it was the realizing the the Lisp metasystem was what we needed...

Barton taught me “The basic principle of recursive design is making the parts as powerful as the whole.” These ideas led me to an insight on November 11, 1966: the timesharing people got it right with processes, but it was too big.

Thursday, February 23, 2006

Wonderfully Empty

In my house there is a cave
And in the cave is nothing at all
Pure and wonderfully empty
Resplendent, with a light like the sun.

- Han shan

Daily Zen

Pig Pile

Bill de hÓra writes (but I transposed it into a question)...

...where could [you] point to a solution and say WS-* was critical to success[?]
And then more...
As for XSD it just does not seem to be helpful. I think that has to do with not only XSD being complicated (due to a requirements creep toward genericity that resulted in something of a monster spec). It's also quite low-level, and in practical terms tends to expose a platform's type system, which is invariably implementation specific. Which is to say there's an encapsulation problem when using XSD - too much how, not enough what. It would be cleaner to expose domain level structures like "Customer" that obey a RELAX or RDF schema...

There is one nice feature about the REST or XML-over-HTTP approach - you can definitely scale down. Scaling down is important because if you can't scale down you presumably have to start big, which is risky for any project, unless you believe big working systems derive form big working systems...

XMPP rocks. Publicly the fuss around XMPP will be in the commercial sector - about Google Talk and Voice Over IM. I think it could quietly become the "other" protocol for the get-it-done school of systems integrations, mainly in situations where push or timeliness is a serious need, and people are talking crazy talk, like long haul JMS integrations.

This is Enterprise Stuff. Look Out

A comment on Bill de hÓra's blog from Mike Champion continues the theme of wizards hiding complexity reining supreme...

...the paying customers in my world DEMAND that intellisense and databinding stuff that people in the web geek world think is gratuitous fluff.
Intellisense and code generation is an isolated developer trick for hiding real complexity and risk. This has nothing to do with architecture, maintainability, interoperability, etc.

If that is the reason for choosing SOAP/WSDL then... it really is over.

It also remains to be seen whether RELAX NG, RDF Schema, etc. are also just simpler tools for simpler jobs than XSD, or really do more with less. I'd be extremely happy to be proven wrong that XSD is a necessary evil!
Yes, why list actual reasons why XSD is good when you can just claim the top of the hill and dare people to knock you off. I think you might fall down on your own.

Customer-Driven Design or Not

Scott Bellware writes in the Test-Driven Development Yahoo group...

Sweet mother of God! MS TDD® is back! :)

I recently got an update on the revision to the Guidelines for Test- Driven Development article on MSDN. An actual TDD practitioner was tapped to write the second rev of the article. I learned that the product folks weren't overly pleased with a more accurate depiction of TDD as it didn't promote the VSTS testing features that they had worked so hard on.

That'll learn 'em. Or not.

If it keeps on raining...

The levee is going to break. Steve Loughran contributes more to the discussion I was hoping to see. I would like to see some constructive counter-arguments. Where are they?

Let it not be said that I critique SOAP/WSDL and the like for ideological grounds. I critique it because I have to use it, and it sucks...

One of the key features is that its easy to debug HTTP problems: point a web page at the same URL, and see what you get back. Work with SOAP, and you are doing tracelogs...

We cannot reliably send an xsd:dateTime between two endpoints on the same machine without its timezone getting confused, attachments are something you need to negotiate on, and nobody even understands why xsd:nil actually exists, since its a way of declaring inline "I choose to break this bits of the public schema, get over it"...

In REST-land, few people work with XSD, even less try to seamlessly map from the schema to native types, and nobody expects the runtime to infer a REST state model from implementation classes. Yet despite the lack of all this integration, REST appears to work better...

Just as Hibernate killed EJB-classic, so can lightweight protocols kill WS-*...

Use XMPP as the back channel. Not WS-Eventing, or WS-Notification. Or let people poll. It actually works quite well when the number of polling clients is very low, as it probably is for most communications between two nodes, and it works around the whole firewall problem...

...kill WS-Addressing. WS-A is the recurring bane of my life. People ask me why, and I have to point them at code that tries to move data to and from the various versions of wsa:epr on the wire. URLs, that's all you should need. If you want async two-way comms, then give a URL for responses; an xmpp: one for xmpp responses...

Wednesday, February 22, 2006

Bad Idea

Robert Sayre makes the point that it really is over after all...

With the benefit of hindsight, we can see it was a bad idea to try and abstract away application protocols using RPC calls tied to verbose, rigid, statically-typed languages mapped with a Rube Goldberg schema language that has a more flexible type system than said languages...

If you have Microsoft saying "well, the best approach is to make this elaborate infrastructure we've spent billions of dollars building out optional", then the debate is over.

Update: More about this bad idea. First, Tim Bray writes about either WS-angst or WS-flurry or both...
I think the WS-stench of something WS-rotting from the WS-head down is becoming increasingly difficult to ignore.
OK, not much information there but a telling satire on the WS-mess. But Dare Obasanjo informs us...
The main problem with WS-* interop is that vendors decided to treat it as a distributed object programming technology but based it on a data typing language (i.e. XSD) which does not map at all well with traditional object oriented programming languages. On the other hand, if you look at other XML-Web-Services-as distributed-objects technology like XML-RPC, you don't see as many issues. This is because XML-RPC was meant to map cleanly to traditional object oriented programming languages.
I think this has a ring of truth. XML-RPC for all its flaws is fairly modest and easy to implement. The data model is not unlike JSON, again really modest and easy to implement. JSON is even better because it is just a data representation and can just use plain HTTP.

Tuesday, February 21, 2006

Truth

"I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth."

-Umberto Eco

History

"Human history becomes more and more a race between education and catastrophe."

-H.G. Wells

Merit

"In science, 'fact' can only mean 'confirmed to such a degree that it would be perverse to withhold provisional assent.' I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms."

-Stephen Jay Gould

Monday, February 20, 2006

Don't Make Me Think

"Don't Make Me Think" may be a fine motto for user interface design. Unfortunately, this seems to be the preference of developers promoting the SOAP/WSDL/IDE approach. As Mark Baker points out, the result is not an architecture based on principles. The choice appears to be driven by convenience. A C# or java programmer can point and click their way to non-interoperable code generation almost without thinking.

Look around the net for the architecture principles for SOAP/WSDL. Then look around for HTTP/POX. It's like night and day. Maybe an architecture isn't required if all you need to do is point and click within a single IDE and toolkit.

From what I can tell the problem with interop is:

  • The SOAP/WSDL solution space is big, far bigger than HTTP.
  • Each vendor seems to be in it for their own benefit rather than the benefit of the whole.
There is no way the web could work under those conditions and it appears the WS-* world is not working well under those conditions. Vendors might have trouble differentiating themselves under simpler conditions though. The HTTP advocates are essentially saying an open source system like Apache, or simpler still, is sufficient. The vendors are between a rock and a hard place.

Simple dynamic programming languages and simple dynamic coordination languages are winning. Vendors will have to differentiate themselves on something more than wizards that mask complexity.

The China Syndrome

For some reason the search engine business is not supposed to profit from China's poor support for human rights. Meanwhile the rest of us are able to do business under their current conditions in the name of "democratizing" their country.

Right.

Sunday, February 19, 2006

Java and SOAP/WSDL

Philippe Mougin writes in a comment on Don Box's blog...

I'm quite surprised by Don Box's comment about SOAP/WSDL providing a great experience to Java folks. JAX-RPC (the standard Java API for using SOAP and WSDL) is known to be a terrible API...
Several years ago I used a fairly nice SOAP toolkit called Glue. I recently worked with SOAP again for the first time since then. This time around we tried Glue, Axis2, and another based on JAX. Glue remains by far the nicest and yet still presented problems with interoperability even among Java toolkits as well as various dotnet toolkits.

Web Methods owns Glue now. I don't know how well they've incorporated Glue into the rest of their products. They seem to bury Glue per se deeply in their web site for some reason.

Dyanamic Languages, Part L

Lisp implementations are nearly 50 years old! The ideas go back publicly 50 years to John McCarthy's participation in the Dartmouth AI project in 1956. By 1960, McCarthy had reported publicly on his team's implementation experience.

Here is a two-line status report on dynamic languages 50 years later, quoting from another blog in another debate...

  • If you want a great experience for .NET/Java devs, you’ll typically publish schemas (through wsdl) and support SOAP.
  • If you want a great experience for LAMP folks, you’ll support POX messages and will provide a non-XSD description of your formats.
And so I would summarize the status of dynamic languages like this: they are mainstream, they are everywhere, and they are so misunderstood.

Update: Phil Windley has some recent items on Lisp.

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About Me

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.