Friday, May 20, 2005

Rocky Lhotka talks about SOA hype at CNUG meeting

At Wednesday's CNUG meeting Rocky gave a presentation before a packed room on The State of Distributed Application Development. I call it Debunking the hype over SOA. He has been discoursing on this for some time on this in print and in postings at his site and others.

He showed slides outline the history of distributed applications and suggested that not much has really changed over the past twenty years. He said we are still solving the same problems.

Among his many observations, many in the form of analogies...

  • Many of todays thin-client technolgies hark back to days of dumb terminals attached to big iron. He came from a VAX background.
  • He described two views of SOA - Academic versus Practical?
    Academics have a model of autonomous, independently acting objects which communicate (asynchronously) via messages. The Practical (largely vendor driven) approach is really data-centric. He said pure Web Service calls are just like DB Sprocs!
  • Hardware and Networking Technology combined with better app server software have made two-tier client-server applications an appropriate technology again today (in response to a question from Mike Disbrow, who termed it regression). Whereas in the 90's it could only support 30 concurrent users, today it can handle 300, which is enough for most applications.
  • Today people are applying SOA and webservices in many scenarios where they do not make sense, but it is appropriate in some.
  • He rather ridiculed "Contract-first" WS development, but I've forgotten his reasoning.
  • His preferred solutions involve layers where BL is in the middle layer but replicated to smart,flat clients for UI performance. He did not detail just how that replication is accomplished.
  • Finally, with respect to building distributed applications, he said "Just say no".

Many of the questions, and mild arguments came from older developers with a long heritage going back to mainframe days. He had particular fun with a fellow who said he does like to put BL into the database(sprocs). Later it turned out that fellow was doing that in part to extend the functionality of expensive vendor apps which did not publish a useful API.

Though he was to some degree flogging a straw man it was overall a worthwhile and enjoyable event.
Along the way he recommended several books:
David Taylor - Object Technology: A Manager's Guide
Some book on COM and CORBA (have to find the reference)

Rocky has written extensively on this topic on his blog and at
Here are some links to some of those posts:
SOA is really just RPC with angle-brackets
Can a Service have Tiers?

These are some articles he has posted at
The Intersection of Objects and Services
The Fallacy of the Data Layer


Blogger Allan Wolff said...

Links to some more recent posts:

9:14 PM  

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