>Lack of concurrent processing. For example, lets say you and I have instanced the same COM Object on a server. You invoke a method on that object that takes 30 seconds. I then invoke a method that will only take .10 seconds. I have to wait until your method has completed its operation before my method will execute.

This is the case if your using a Multi Use instancing InProc OLE Servers. VFP 6.0 supports Apartment Model threading and MTS support. This doesn't really help in scaling apps since the VFP runtime won't process multiple instances to execute simultaneously(as you have stated above). Actually MTS in all the MS hype does not provide server pooling. All it really does is load and unload servers as required relieving the client of this duty. MTS just makes it less complex to build n-tier apps with no real performance benfit. Server pooling really what is needed to build scalable apps.

It can all be done in VFP with a Mediator design pattern and Single Use instancing OutOfProc Servers. The mediator handles all the logic - request routing, references to servers and logging of all server execution times and requests to VFP tables. The information gathered by the mediator can than be analized for performance tuning - how many servers should be running during certain times of the day. Taking this approach you can build a complete VFP middle tier frameworks giving more flexibility and taking advantage of the VFP data capabilities. A VFP scheduling module could also be interfaced with the mediator allowing regular processes to be mixed with user requests.

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>In VB, my method would kick-off right away since concurrent processing is supported.

This is true in MTS. If I were building a data warehouse reporting middle tier I centainly wouldn't want to use VB for data manipulation tasks. If MS really wants VFP as the middle tier development tool the concurrency issue with the VFP runtime needs to be addressed soon.

I don't think MTS is much of a scaling solution until server pooling is supported. The only thing MTS does is provide simple manager of COM components with little scaling benefits since the components are continuously created and released. A complete VFP middle tier frameworks is a better solution from a flexibiliy and performance standpoint.

Billy D.
Black Diamond Software, Inc.
Building Better Information Environments