Distributed environment

[Gerrit van Dyk]

Hi all,

I am in the process of designing a system that will need to use a 
distributed environment. 

The system will consist of multiple (thin) clients += 100-200 that will need 
to connect to a central server. The client applications is not 
browser-based as they need to do a lot of data manipulation, draw charts, 
run scenarios etc. The idea is to do most of the processing on servers 
except for the GUI stuff. 

Several different services will be registered with the central server to 
supply different types of services (rate feeds, risk analysis, forecasting 
etc). 

The central server(HUB) needs to control all the services and clients. When 
a request comes in from a client, the HUB needs to distribute this request 
to the correct service. Multiple services could be registered for the same 
type of service. This will enable multiple clients to use the same type of 
service concurrently. The services could also make use of relational 
databases or other types of data stores. The client applications will have 
no concept of data storage and will have no direct access to the databases.

In some cases, some of the services will be needing the services of other 
services, in essence also becoming clients for the other services.

The central server (system) needs to keep track of all the clients and their 
requests. This is to ensure that if a machine or service fails the system 
should be able to recover without affecting the clients at all. The system 
needs to be up 24/7/52.

These services will also be distributed across multiple machines for load 
balancing.

My questions are.

Is this feasable? 
Any pointers or pitfalls I might step in?
Which environments would you recommend I should look at, for doing this type 
of thing?

Regards
Gerrit