Re: [Gnumed-devel] gnumed architecture

[Roberto Mello]

On Mon, May 26, 2003 at 11:38:36PM +1000, Horst Herb wrote:
> Somehow we are moving in circles.
> 
> The original idea was a three tier architecture: user interface, 
> transactional 
> middleware, and dumb datastore
> 
> However, no matter how hard I tried, I found no way of reliably preventing 
> users from bypassing the middleware and doing stupid things on the backend, 
> so we decided to scrap the middleware and implement as much bsiness logic as 
> possible on the server via stored procedures

Seems simple enough to me.
 
> Then, the concept of splitting the monolithic database into "black box" style 
> "services" was requested and generally found useful. Since the backend itself 
> has trouble preserving referential integrity between databases, we again 
> needed some "middleware".

Forgive my ignorance of gnumed history here, but why was this decision
made? It seems that it will only complicate our architecture to the point
that we will either take a very long time or never get off the ground.

It all depends on what we are trying to accomplish. My impression was that
gnuimed was to be a software for doctors. Most software I've seen that
tries to complicate things in order to please programmers with cool stuff
ends up not being used.
 
> Strangely, this middleware layer slowly seemed to creep into the user 
> interface layer via "business objects". Now the UI client gets fatter and 
> fatter. Do we want this?
> 
> I spent the past 4 month doing nothing else (for gnumed) but rethinking our 
> architecture. I tried out a large number of distributed service concepts 
> (DCE, SOAP, XML-RPC, CORBA, and dozens of esoteric ones). To my shame I must 
> say that te best performing language independent one I found so far is CORBA 
> which I initially outrightly refused for it's complexity. It still has quirks 
> with authentication, but it is fast.

I guess my question is "why do we need a distributed objects system?"
 
We may want to look at the twisted folks and see if they have something
that we can use.

-Roberto

-- 
+----|        Roberto Mello   -    http://www.brasileiro.net/  |------+
+       Computer Science Graduate Student, Utah State University      +
+       USU Free Software & GNU/Linux Club - http://fslc.usu.edu/     +
Thou shall not kill, unless it's for dinner!