OFTT: A Fault Tolerance Middleware Toolkit for Process Monitoring and Control Windows NT Applications

This paper describes the OFTT (OLE Fault Tolerance Technology), a fault tolerance middleware toolkit running on the Microsoft Windows NT operating system that provides required fault tolerance for networked PCs in the context of industrial process monitoring and control applications. It is based on the Microsoft Component Object Model (COM) and consists of components that performs checkpoint-saving, failure detection, recovery, and other fault tolerance functions. The ease with which this technology can be incorporated into one application represents the primary innovation. It is hoped that by making fault tolerance more compatible with standard software architectures, more reliable PC-based monitoring and control systems can be built conveniently.