Middleware Matters

Just a reminder that the deadlines for the Distributed Objects and Applications conference (DOA) are looming. June 8 is the (extended) deadline for abstracts, and June 15 is the deadline for full paper submission.

Ted Neward explains his opinion regarding the current state of web services tools. This is the same topic that we covered a couple months back.

In general, it's good that we're seeing more and more agreement that directly exposing objects as web services is a less than stellar idea. I've written several articles about this in the past (e.g., this article and this article). As I've also mentioned before, it's deja vu all over again. A decade ago, people were trying to expose programming language objects directly as CORBA objects. Same basic idea, and just as wrong then with respect to CORBA as it is now with respect to Web Services.

On the minus side, in my experience, preaching about the correct way to do things back then wasn't 100% effective, and so I don't hold much hope for preaching about it these days either. The problem is that, as a toolkit provider like IONA, you can tell people until you're blue in the face that they shouldn't directly expose their objects as web services, and many of them will nod at you and tell you they agree with you, and then they'll turn around and demand that you provide tools to let them do just that!

On the plus side, in some cases, such a direct export is OK. If someone's done a reasonable job of abstracting a CORBA system, for example, then exposing it as a web service or set of web services can work just fine. I've seen several customers with such systems.

Since the customer is always right, if customers want a way to expose their objects directly as web services, that's what we give them. I'd say that's how a lot of toolkit vendors and suppliers feel. While providing such capabilities enables the customers who've already properly abstracted their underlying systems and objects to do what they want to do, it also enables those who don't understand the issues to do the things they shouldn't. There's no easy way around this. As long as toolkits and standards continue to target the development of web services in languages like Java, C++, and C#, this problem will continue to exist, due to the general mismatch of the abstractions involved.

The general chairs OTM 2004 have decided to extend their deadlines for abstract and paper submission, which means that deadlines for the Distributed Objects and Applications (DOA) conference are now as follows:

• Abstract Submission Deadline: extended until June 8, 2004
• Paper Submission Deadline: extended until June 22, 2004

I wonder if Apple's new AirPort Express and AirTunes combination is any better than my Squeezebox? I love OS X and iTunes, but personally, I think the Squeezebox totally rocks, especially given its open source SlimServer software, written in Perl (though I think it would be even cooler, and a whole lot smaller and easier, if it were written in Python using Twisted). The AirPort Express is 802.11g, so is faster, but I experience no dropouts or other problems whatsoever running my Squeezebox for hours and hours over my 802.11b network, so that's not an issue for me. Overall I think it's cool that Apple has created this combination, but I'll stick with my Squeezebox, thanks.

New music and music-related toys:

• I got a Soundgate auxiliary input converter that plugs into my car's CD changer auxiliary input and allows me to plug my iPod right into the sound system. Very sweet!
• Well, almost very sweet. Problem is that the line level is too low, so I have to crank up the volume on both the iPod and the sound system to be able to hear anything. Worse is that when I arrive at my destination and exit the vehicle, I invariably end up taking the iPod with me, popping in the earbuds, and proceeding to make myself jump out of my own skin because I forget to turn the iPod down first! Easy fix, though: a Precision Interface Electronics LD-1 adjustable line driver to act as a preamplifier.

Of course, having more great music to play through this setup is always a necessity. Lately the following CDs have been getting a lot of my attention:

• "Hangover Music, Volume VI" by Black Label Society. Some BLS fans don't like this CD, apparently because it's not the typical all-out Zakk Wylde aural assault typical of previous BLS CDs, but those people must not have experienced enough hangovers to appreciate the music Zakk has put together here. The album title is perfect -- this is hangover music, and damn good hangover music at that. Zakk is just an amazing and outstanding guitar player, whether electric or acoustic. (Too bad his website doesn't work with the Apple Safari browser though!)
• "Live at Bonnaroo" by Warren Haynes. Warren is the man. Not only does he play with the Allman Brothers, not only does he play with The Dead, not only does he lead his own band Gov't Mule, and not only does he play with Phil Lesh & Friends, but in his "spare time" he plays solo acoustic, which he does on this CD for the huge crowd at Bonnaroo last year. This CD is simply excellent. And BTW if you don't own any Gov't Mule, you can't consider yourself a rock fan -- it's that simple.
• Speaking of the Allman Brothers, their latest live CD "One Way Out" has been living in my car CD changer ever since it came out. This thing is great, showcasing not only Warren Haynes but also Derek Trucks, who is also an amazing guitar player in his own right, and who also fronts his own The Derek Trucks Band.
• Today I picked up the new Velvet Revolver CD called "Contraband," their first. These guys do not disappoint. If you like Stone Temple Pilots or Guns N' Roses, you will like this too. Go buy it.

R.I.P. Ray Charles, none of this music would even exist if not for you.

I'm here in Palma de Mallorca, Spain, and just delivered the closing keynote for the 9th International Conference on Reliable Software Technologies Ada Europe 2004. This town and island are unbelievably beautiful -- or so I'm told. I've been holed up in my room for two days finishing my keynote and working on presentations for next week. :-(

I'm not an Ada person, nor a reliability expert, and I don't know anybody at this conference or in this technical community, so I've felt somewhat out of place being here. But that's part of the reason they invited me -- they wanted someone from outside their community to come and talk about middleware. I first gave a general overview of middleware history, talked about some of the reliability challenges middleware has faced in the past, and then presented some future challenges, including

• "middleware for middleware" integration (which we tackle with our Artix product)
• middleware for distributed real-time and embedded environments
• mixing "ilities" (i.e., effectively combining qualities such as security, transactions, management, versioning, configuration, etc. all within a single cohesive system)
• the woes surrounding Web Services standards
• and one of my favorite topics, middleware "dark matter."

It's hard to give a meaningful middleware talk in only an hour, but it seemed to be well received, or maybe they were just being polite. :-) Overall, these are a great bunch of people who made sure that I didn't feel like a stranger. I might have to go learn Ada just so I can hang out with them some more!

I would love to stay and vacation on this Mediterranean island, but duty calls. On Monday I'm presenting at the OMG meeting in Orlando to continue to convince them that issuing a request for proposals (RFP) for a standard CORBA binding for WSDL would be a good thing to do, and also to present a status report on my continuing work on CORBA reflection.

I just returned home from my 4th OMG meeting in a row, this one in Orlando (combined with a Disney vacation with the family, all of us except for our 20 year old son who is currently following Phish around half the US on their final tour). I say "in a row" because prior to the first of these four -- in London last November -- I hadn't attended an OMG meeting since February 1998 in Salt Lake City.

Why am I attending these meetings all of a sudden? First, to try to get my CORBA reflection work standardized, and second, to try to get an OMG RFP issued for a CORBA binding for WSDL. At this just-completed Orlando OMG meeting, I gave presentations on what should be the final drafts of each of these works. Both presentations went well, and the OMG MARS task force seems ready to vote their approval. At the next meeting in Montreal in August, I hope to present the final version of each work to the MARS task force, and also to the OMG Architecture Board to obtain their approval as well.

I believe CORBA reflection/introspection is important because it allows CORBA applications to play well with others, especially web service applications. Unfortunately most CORBA applications are devoid of runtime metadata discovery capabilities, since CORBA historically has limited such capabilities to the Interface Repository (IFR) service, and few real-world applications use the IFR. Ironically, every CORBA object possesses complete knowledge of its interface(s), types, operations, etc., and yet the information is completely invisible to users of the object. CORBA reflection, which is based on an ordinary IDL interface and can be completely code-generated by an IDL compiler, allows a CORBA object to answer queries about its interface at runtime. It's quite simple, really.

CORBA bindings for WSDL are important for allowing existing deployed CORBA applications to continue to work, untouched and without bridges or gateways, in a web services world. They allow a CORBA object interface to be described in the logical part of the WSDL description, and allow the object's communication mechanisms to be described in a binding as part of the physical part of the WSDL description. Communications with the object therefore go over whatever protocols and transports the object's interoperable object reference (IOR) specifies (typically IIOP). Our experiences with our customers using this capability, already provided by our Artix product, show that while not all CORBA objects can be redefined in WSDL, many CORBA objects in practice are quite compatible with WSDL, and the redefinition effort for these is well worth it.