Comments on Mark Little's WebLog: Complexity theory

I agree with "if you go down that route without th...

2006-06-08T00:55:00.000+01:00

I agree with "if you go down that route without thinking too much about the underlying model (SOA), you end up just doing distributed objects over SOAP/HTTP, which isn't what we want."

The distributed world is inherently unreliable.

Should we make it appear to be reliable, and abstract away it's unreliability? Of course not.

Similarly, some of the complex things we may wish to do over WS like 2PC may actually be the wrong world view.

Remember when people started programming distributed objects as they would ordinary objects? Again, case of bringing the wrong paradigm into the distributed world.

As engineers, we all like to believe we can create the world we want. But first, we have to see the web for what it is.

Disconnected, Notification-based, Coarse-grained interfaces.

Discoverability is overrated IMHO. I've never seen someone migrate an Oracle app to SQL Server without porting. Similarly, I don't think anyone will be switching services on the fly.

I think there's definitely room for abstractions, ...

2006-05-05T13:47:00.000+01:00

I think there's definitely room for abstractions, but just not within the WS-* arena. I'd put that in the space of particular language bindings. The problem is, however, that if you go down that route without thinking too much about the underlying model (SOA), you end up just doing distributed objects over SOAP/HTTP, which isn't what we want. MSFT started down that route (primarily because of the existing tooling). I haven't checked recently, but it wasn't pretty and did encourage an OO style. That's fine if all you want is interoperability (which is very important, so don't get me wrong). But if you want loose coupling, that's not the right approach IMO. (Take a look at WS-RF for an example of how quickly Web Services can degenerate into OO.)

I think there's definitely stuff that can be learnt from the Grid community, but it's a two-way street. The WS community has been educating them on not reinventing the wheel (ironic, I know!) so they're now looking to leverage Web Services (but please not WS-RF!)

Back in 1995 the OMG had put the finishing touches to its basic architecture. There have been many revisions since, but enterprise deployments happened pretty quickly (for better or for worse). I think there's a good chance Web Services could have as quick a take up simply because there is so much momentum behind it. The downside is (as happened with CORBA) companies may use technologies (implementations) that aren't up to the task and live to regret it!

Hi Mark,Cannot imagine fitting all your subject ma...

2006-05-05T13:24:00.000+01:00

Hi Mark,

Cannot imagine fitting all your subject matter into one hour. I agree 110% with you that it is not Simple and in essence is difficult to make easier - However I think there may be ways to abstract the complexities giving the illusion of ease. I wonder if the difference with Java and the WS-* specs is that there is a tighter reference model/architecture for vendors to work within. Perhaps frameworks like SCA can be applied within the context of (dare I say it) 'tools' that could use more a Model Driven approach - thus making it easier for the typical company to implement. Perhaps Grid Computing can offer a simpler means for scaling and monitoring. I cannot help but read the WS-* docs (yes I have too much time) and believe that it is 3-5 years outside the mainstream, I would be interested on your thoughts.

Take Care,

Jason