Lessons learned in building a fault-tolerant CORBA system

The Eternal system pioneered the interception approach to providing transparent fault tolerance for CORBA, which allows it to make a CORBA application reliable with little or no modification to the application or the ORB. The design and implementation of the Eternal system has influenced industrial practices by providing the basis for the specifications of the fault-tolerant CORBA standard that the Object Management Group adopted. We discuss our experience in developing the Eternal system, with particular emphasis on the challenges that we encountered and the lessons that we learned.