We have a Delphi 5 application which is built as a client-server application with http-based data exchange between server and client sides. The server side is designed as an ISAPI DLL module, which connects to database in response to the client requests obtained through HTTP messages. The server-side module uses ADO for the database connectivity.
Our problem is after subsequent requests from client application, the web server (IIS 6 and 5) stop responding. Dllhost process will show constant CPU usage but the database server will not be under any load or show evidence of outstanding /incomplete efforts. Server ISAPI DLL is somehow overloaded and stops responding. Unloading the DLL normally fail, a full iisreset is used to ensure the system is returned.
Please provide suggestions to identify the problem and how to solve this issue.