Middleware Matters

A couple colleagues of mine here at IONA, Frank Lynch and Mark Fynes, have just published an article over at the WebServices Journal entitled "Where HTTP Fails SOAP." It discusses scalability problems that can arise when applying SOAP/HTTP in the enterprise back end. Given that it seems that many people just assume that SOAP/HTTP is the end-all and be-all of protocols, I think Frank's and Mark's article provides some unique and useful insights into where and why SOAP/HTTP can come up short.

My blog's been kinda quiet lately, not only because of workload, but also due to weekend trips I've been taking with my son Ryan, who's 21, to a couple flying disc freestyle tournaments, where we competed together as a team.

The first was in Narragansett, Rhode Island, where we took 6th place in a very strong field. If I'm not mistaken, each of the five teams in front of us had at least one player who attended the recent freestyle world championships in Seattle, plus there were two former world champions competing in the tournament. It was tons of fun, despite the significantly hot weather.

The second was outside Louisville, Kentucky, where we managed to take 2nd place. It was also really hot, but also a lot of fun. Freestylers are just the coolest people on the planet.

Here's a couple photos of Ryan making some catches during our Narragansett routine:

The second catch is called a flying gitis (pronounced "GUY-tiss"), where the catch is made in the air with the opposite hand over the leg with the palm of the hand up. Try it, it ain't easy.

And here's a couple of me, with the first showing me setting up for a back roll, where the disc rolls from right fingertips to left fingertips across the top of my back:

In the second one, I'm rolling the disc across my chest with the disc upside down. Ryan threw the disc to me with counter-clockwise spin, which I caught spinning on my fingernail on my right hand (which is called a "nail delay"), and then with the fingernail of my left index finger, pressed on the top of the disc to turn it over into an upside-down clockwise spin, and then chest-rolled it from left to right. I can't jump like Ryan anymore, so I like doing a lot of slow, smooth body rolls like these.

Thanks to my friend Mark Ide for the photos.

Dave might like Ultimate, which is cool, but having played both, freestyle is just way ahead for me in terms of both challenge and fun.

Over the years I've written a fair bit about the impedance mismatch problems that crop up when mapping from one representation/abstraction to another. Perhaps all the pain of being involved in OMG language mappings for many years is what started it all. One of my first Toward Integration columns from a few years back outlined problems with mapping existing technologies straight to web services (PDF), and a Object Interconnections column from four years ago co-written with Doug Schmidt discussed why mapping CORBA straight to web services wasn't such a good idea. I also later wrote a Toward Integration column explicitly about the mapping problem. I've given talks about the problem at several conferences over the years as well.

After reading Steve Loughran's and Edmund Smith's excellent paper (PDF) about the mapping problem as it relates to JAX-RPC earlier this summer, I've been obsessed with the problem. My upcoming September/October Toward Integration column will discuss it, for example. Basically, unless I'm real busy doing something else, my thoughts invariably turn to the impedance mismatch problem. I spend a fair bit of time searching for what others are doing to solve it, and I know about Comega and some of the domain-specific language ideas, but finding relevant work is hard because AFAIK there's no crisply defined category for such work.

Can you help? If you know of work going on to eliminate or overcome the impedance mismatch problem between programming languages and distributed messages, especially where XML is concerned, please drop me a line with a pointer. Please don't limit things to Java, either, and extra points for work in dynamic languages, especially Python. I'll collect and summarize here later.

Via Stefan, some commentary from the prolific Elliotte Rusty Harold about the WS-Addressing core and SOAP specs recently reaching W3C Candidate Recommendation status. My favorite line is this one:

Besides nobody's actually doing web services over anything except HTTP anyway.

Mr. Harold appears out of touch with what's going on in the enterprise integration space, where folks are doing web services over MQ, JMS, IIOP, and a variety of other protocols, not only because these are the protocols that are actually used in the real-world enterprise, but also because HTTP has issues for certain approaches to enterprise integration. Now, the obvious counterargument is, "Well, those aren't real web services." Even though that's a rather pointless purist argument, I've nevertheless already explained in detail why I beg to differ.

I could write more about Mr. Harold's apparent misconceptions in this space, but Ted Neward has already taken care of it, so I'll just point people (hopefully including Mr. Harold) to my "Toward Integration" columns since quite of few of them cover web services and have already covered this topic in great detail.