Tag Archives: w3c

Fence sitting arguments

Mark Little responds to an interesting post by Bill Burke about compensation based transactions. I don’t really have any direct response to the gist of that discussion, but wanted to highlight a couple of Mark’s arguments that I consider to be probably the top two arguments by those who feel there’s value in both the Web and Web services (the “fence sitters”, as Mark recalls me calling them 8-).

First up, the belief that the Web has nothing to say about reliability, transactions, etc… Mark writes;

Yes, we have interoperability on the WWW (ignoring the differences in HTML syntax and browsers). But we do not have interoperabilty for transactions, reliable messaging, workflow etc. That’s not to say we can’t do it: as I said before, we did manage to do REST+transactions in HP but it was in a small-scale deployment involving only a couple of partners. There is no technical impediment to doing this: it’s entirely political. It can be done, I just don’t see it ever being done. Until it happens, REST/HTTP cannot compete with the kinds of heterogeneous out-of-the-box interoperability that we have demonstrated with WS-*

I’ve talked about this a lot, most recently in my position paper to the W3C Workshop on Enterprise Services. The gist of the argument is that the Web address all of those needs, just in a way which you might not recognize because it has to address them within the confines of architectural constraints that Web services folks aren’t used to. Again, that’s not to say that every possible one of your needs can be met out of the box today, only that far more of them can than you might believe.

Mark also uses the very common argument that because interoperability requires agreement on data for both Web and Web services, that there’s no significant difference between them (I hope that summarizes his point);

So just because I decide to use REST and HTTP doesn’t mean I get instant portability and interoperability. Yes, I get interoperability at the low level, but it says nothing about interoperability at the payload.

I can’t quickly find any past blog entries that touch on this point (though I know they’re there), but this argument I find the most confusing. I suspect it has to do with what I perceive to be a disconnect between Internet and intranet protocol stacks, but I can’t say for sure.

What Mark calls the “low level” isn’t the low level at all. Assuming he means HTTP, the agreement you get by using it is more (higher level) agreement than you get if you were just using SOAP (or XML-RPC or IIOP or BEEP or …). That’s because you’re agreeing on the methods in addition to an envelope (not to mention many other features).

Google Gears: too much interface?

So I had a quick look at Google Gears this morning. Unlike some, I do most definitely see value in supporting disconnected scenarios, not because I don’t see pervasive wired and wireless networks being the rule in the not-too-distant future – I do – but because I understand that networks are unreliable. That said, I do have some concerns about how Gears was put together.

My primary concern is that I’ve always felt that supporting offline use in existing browsers required more innovation of implementation rather than interface, whereas Gears is all about interface. What I mean by that is that I believe that a better, more easily deployable and usable solution would be for Mozilla itself to tweak the implementations of its HTTP stack, cache, and XMLHttpRequest object. Instead, Gears gives us new interfaces like LocalServer, which developers are supposed to use to check for valid cached representations before hitting up XHR: something XHR could very well do itself, largely transparently (I expect – haven’t considered all the backwards-compatibility issues).

Now, Gears could very well be something that was deployed for its ability to enable features today, because Google didn’t want to have to wait for HTML 5 (and its equivalent of client-side storage) to be deployed. And from that perspective it’s great (though requiring a plugin is a bit of a pain). I just hope that the Gears folks are talking with Hixie and Mozilla about where to draw the line here.

links for 2007-02-09