Hi Eric,
On Jun 7, 2007, at 7:17 PM, Eric Newcomer wrote: > What's frustrating are statements like "Web services have no value" > or "Web services are just RPCs with angle brackets" that are not > fair descriptions, especially from folks who participated in the > Workshop in which every effort was made to accomodate the various > viewpoints and have a balanced discussion. I thought we had > achieved something there - acknowledging the pros and cons of both > approaches and getting past the oversimplifications and > overstatements - so it is discouraging to see it continue. That's > all. I honestly would like to see the pros and cons of WS-* and REST discussed. I don't believe we have, so far - on this list, the recurring theme is that somebody either (a) points out that REST is better or (b) REST is not suitable for machine-to-machine communication. [I'm guilty of (a), although I have a clear conscience about it :-) ] But I can't recall much serious discussion about the benefits WS-* has over REST. So, considering the benefits of SOAP/WSDL/WS-*, I can see them fall into two categories: Political (or "soft") factors: Reasons in this category are based on the acceptance of WS-* among vendors, analysts, and because of this, among end-users. I know from personal experience that (at least currently) it's much harder for a consultant to convince a client to use HTTP in a RESTful way instead of Web services, since Web services is all they ever hear about. This might mean that it's easier to get them to adopt the WS-* architecture, which may be a significant step forward for them. Let's just assume that in many cases, the "you will not be fired for choosing WS-*" attitude is a good enough reason. Technical (or architectural) factors: Politics aside, you seem to believe, no: you consider it _obvious_ that there are situations where WS-* is superior to REST from an architectural or technical point of view. What are those? I'll make some guesses (note that these don't reflect my opinions) (1) WS-* is "protocol independent", while REST (in all practical relevance) is tied to HTTP. (2) The WS-* specs address "enterprise" concerns that REST/HTTP can't handle (3) It's much easier to expose an existing system that has a "transactional" interface (in the TP monitor sense) via WS-* than via REST, since the latter requires a real architectural change and the former doesn't Are there any other benefits that WSDL/SOAP/WS-* is claimed to have over REST/HTTP? For the record, I believe that (1) is an illusion since the HTTP protocol is just replaced with a different protocol, one that has no or at least a much worse design, and the protocol independence is an extremely leaky abstraction in real applications anyway; regarding (2), the specs that do address enterprise concerns are not yet widely adopted anyway and in many cases address something that doesn't belong in the infrastructure layer anyway. I do believe that (3) is a valid point. Best regards, Stefan -- Stefan Tilkov, http://www.innoq.com/blog/st/
