November 13, 2007

To see what is in front of one's nose requires a constant struggle

Monsieur Dubray has posted nearly 5 blog entries critical about REST.

Almost everything Mr. Dubray claims "you're on your own" with REST is either a tremendous misunderstanding, an emotionally projected argument, confuses implementation technologies with protocol-based interoperability (e.g. SCA and SDO are jokes until it binds to the Microsoft stack, JJ), or it is in area where you're equally on your own with WS-*.

Contracts? WSDL is not a contract. XSD is not a contract. WS-Policy neither. They're interface descriptions. True contracts? You're on your own. By the way, REST relies on *very clear* contracts, as clear as anything in a well designed SOA. The difference is in how the architecture determines & applies them.

Versioning? XSD is notoriously flawed in this regard (though they're working on it). And there is more than that -- SLAs (no standard), security (WS-SecurityPolicy covers only some use cases), etc. You're on your own.

I had begun writing a point-by-point debunking, but, life's too short, and I'm busy enjoying Cancun at the moment. No one denies there's a lot of work to do in applying REST (or successor styles) to enterprise work, but that doesn't mean we shouldn't try. JJ, if you would like to have a reasonable conversation about this, let us know, otherwise please keep insulting us, any press is good press. ;-)

REST as a style in support of enterprise SOA is like XML, circa its release in 1997 -- great promise without a lot of satellite specs & infrastructure supporting it (in security, for example, though this is probably going to be fixed next).

WS-* is where CORBA was circa 1997: it will be used to implement some good systems, but there will also be some high profile failures. A number of the specs will likely never be adopted by the mainstream (see WS-CDL, WS-Eventing), though some will definitely improve some ridiculous vendor interoperability disputes (e.g. WS-TX, WS-RM). Plenty of pundits (now bloggers) sing of its imminent triumph (channelling Orfali, Harkey and Edwards), but overall, the framework will not help solve the problem that was used to sell its adoption in the first place: increased agility, reuse, and visibility in IT. I think many WS-* tools actively *hinder* an SOA architect from achieving these goals.

Posted by stu at November 13, 2007 01:25 AM