Middle-tier implementation

Question

We currently have a large multi-tier system written in Borland Delphi. Win32 Delphi clients deployed on Citrix with COM+ middle-tier, also written in Delphi, containing the business logic running on multiple win2k3 servers. The database access itself has been abstracted out to a 'Datalayer' COM+ component and highly tuned to our specific back-end database. Data is transferred between clients and middle-tier as XML data packets.

When migrating to .NET what implementation would be best suited to develop the middle-tier - is COM+ still a valid future proof solution in .NET.

The system has to be very reliable and resiliant with 24/7 uptime and failover, scaleable for a large user base (LAN only - no internet access), high transaction thoughput, manage distributed transactions across multiple databases.

We are currently in the very early evaluation stages of proposing a migration to .NET so need to go through a series of multi-tier prototype models to identify the best architecture to support our needs. I feel a lot of R&D, reading and late nights coming on and would appreciate any advice from experienced .NET developers in this field.

Thanks

Martin Stephenson · Answer

Thanks for your reply. Can you post any links for example code or reading to get me started. I am particularly interested in serialising the data as XML sending to the client application and recreating as a dataset which can be worked on and manipulated. I'm looking forward to learning c# .NET :)

Mahesh Chand · Answer

You can use Enterprise Library to support database functionality and build your DB helper/wrapper class on top of it. It has a Data Access Application Block that has all database related functionality. You simply have to build your own wrapper. In .NET building a multi-tier app is not as difficult as it used to be in MFC/Delphi days. Welcome to the managed world.