I was blown away today when I read Graham Glass’ blog to
Rocky Stewart passed away
this past October. Rocky was a brilliant, out-spoken technologist
and educator who I had the pleasure of interacting with on many
occasions in the mid/late 90s, on and off the Distributed Objects mailing
If there’s any consolation to be taken from this loss, I suppose
it would be that he died flying his plane, which was his absolute passion.
My condolences to his family.
Hmm, somehow I’m just not too excited about things this year. Perhaps
this has something to do with me making the most intriguing prediction –
the inevitable death of Web services on the Internet –
three years ahead, two years ago.
But first, let’s see how I did with
last years predictions…
As alluded to above, I said that Web services would continue to struggle
for adoption on the Internet, and
lo and behold,
that’s the case. Ho hum. +1
I also claimed that another high profile public Web service would be
released. I can’t think of any really high profile announcements this past
year except for
I guess, but theirs seems SOAP-only, and isn’t public. Bloglines announced their
services, but AFAICT,
they’re REST-inspired only with no SOA side. So I guess I flubbed that one.
Ok, so this year, hmmm… As I see it, things have really got to start
hitting the fan in the SOA space. To that end, I make the following two predictions;
- at least one prominent second tier Web services ISV will move away
from WS-* and towards an architectural style which adopts a constrained
interface, such as REST, MEST, MOM, or one of the Grid styles.
- a prominent Web services architect will have a
and realize that the Web is actually what Web services have been trying
to become since they started down the “document orientation” path in 2001.
This person will embrace the Web and REST, though it will be done in a
manner which saves face for them and their employer, thereby making it
difficult to determine that this is, in fact, what has happened.
I did the little I could today, to help with
the cleanup from the horrific Indian Ocean tsunami; I gave to
doing the same.
I just discovered
by David, apparently reprinted from an old
that I must have missed while at XML 2004. While I think I’ve
said my piece
on the topic of distributed objects vs. services, I wanted to respond to a
couple of points in the article …
First, in the “State” section, Dave seems to make the mistake of
confusing the different types of state (or at least the different
locations of state). He says “Web resources that have a URI
that are stateless and work with HTTP GET”, which is clearly not the
case, since any resource that answers a GET request answers it with a
representation of their state. When you hear “stateless” in the
context of the Web architecture, it’s usually in reference to the protocol,
not the resource … though you can, of course, have stateless resources if
you want to.
I’m also not sure where he’s going with “on the Web” bit. It’s a cute
phrase, but doesn’t seem to hold a lot of technical value.
But the next three paragraphs seem to mix the different types of state
up willy-nilly such that you can’t really make sense of it. The major
theme does seem to be about services with state, yet Dave makes reference
to conversational/application state mechanisms such as cookies. Perhaps I’m
Next, in “Network knowledge”, he adds;
Effectively, Web services is remote method invokes but with knowledge of the remoteness.
I won’t disagree with that, but what the heck happened to document
orientation?! That was the single most significant architectural advancement
upon RPC that I’d seen come out of the Web services space since it began
(at least from a service POV – clients were still as
to the services they used as with RPC).
“Everything in moderation, including moderation” 8-) Certainly a propos for the holiday season.
“If you simply build [Extensible Markup Language]-based applications and keep them behind the firewall, you can’t call them Web services” – Amen
In response to an
issue I proposed
in the WSA WG,
can we avoid going down the standard “mark baker” issues here?
Ouch! That hurt. But sure, you can ignore them. You do so at your peril,
but feel free.
You just might want to keep in mind how previous attempts at doing that have
(not) worked out.
post from Dave. A few comments…
I’ve been saying for a while now that I think it’s a shame that SOAP 1.2 didn’t define a general SOAP to HTTP binding that used HTTP as a transfer protocol, for the previous 2 reasons.
It does, Dave. The default binding is a transfer binding; I made sure
of that. I think you’re confusing how people use it with how it’s defined.
Web services proponents generally think that a SOAP envelope is a SOAP
message, yet that interpretation is not licensed anywhere in the spec, and
is even explicitly rejected in the HTTP binding where the
state transition table
clearly shows HTTP response codes affecting SOAP message semantics. It’s
also alluded to in the
where the definition of the two terms differ (you think this was
accidental? Hah! 8-).
I would love it if there was a reasonable way to bridge the SOAP/WS-Addressing world and the HTTP Transfer protocol world, but I just don’t see that each side really want the features of the other side. The SOAP/WSA folks want the SOAP processing model for Asynch, and don’t care about the underlying protocol. The Web folks want their constrained verbs and URIs and don’t care about SOAP processing model.
Avert ye eyes! False dichotomy alert!! You can get the SOAP processing model,
and HTTP as transfer protocol (including asynch, which HTTP handles just fine despite
insistance from many that it doesn’t) simply by using SOAP in the manner prescribed
in the SOAP 1.2 spec and default HTTP binding. In order to do so though, you need
to give up on the idea of a new (non-URI) identifier syntax. This is really not
a big deal!. We are, after all, primarily talking about syntactical
differences here. What EPRs are trying to do is comparable to inventing a new
alphabet for the english language; perhaps there are benefits, but I think the
phoenician alphabet has a, ahem, rather large and insurmountable head start
in deployment, making those benefits – if they exist at all – completely
Dave then makes a really interesting statement of the “protocol independent” variety;
Here’s a test case: Would the Atom protocol switch to using WS-Addressing and then use the HTTP as Transport binding(s) and HTTP as Transfer binding? Seems to me not likely. The Atom folks that want to use HTTP as Transfer have baked the verbs into their protocol, and they won’t want to switch away from being HTTP-centric. And same as I don’t see the SOAP centric folks wanting to “pollute” their operations and bindings with HTTP-isms.
Emphasis on “baked the verbs into their protocol”. Seriously –
no matter how you slice it you’re always baking verbs into a
“protocol”, because an application developer has to know what verbs they’re
using. The problem as I see it, again, is one of nomenclature; that Web services
proponents have a very narrow RPC-inspired definition of “protocol” (transport),
and their mental models built around this definition simply can’t fully absorb
the implications of the broader definition used in the IETF and W3C (transfer).
They simply can’t conceive of something called a “protocol” playing such an
enormously significant role in a distributed system, yet this is precisely
how all existing Internet scale systems are built, and precisely
why Web services proponents haven’t yet realized that the Web is what
they’ve been trying to build, at least since the quest for “document oriented”
services began in 2001/2002.
One might also look at Dave’s statements and ask themselves, well, if they’re
going to be dependent on a protocol, then it might as well be the most successful
one ever developed rather than one which has struggled for deployment anywhere
except behind the firewall. And somebody please remind me; why is it
desirable to be independent of a transfer protocol, but dependent on SOAP the
My Linux box was commendeered this weekend, by parties unknown. I’m still
figuring out how exactly that happened, but after struggling with trying
to make it workable (a
was involved), I gave up and reinstalled.
Kudos to Knoppix,
a real lifesaver.