A fault-tolerant object service on CORBA

There are more and more COSS (Common Object Service Specifications) on CORBA (Common Object Request Broker Architecture) announced by the OMG (Object Management Group), but no common specification about fault-tolerance exists. We propose a "warm stand-by" replication approach. When an object (primary object) is invoked, it will invoke a secondary object, and the primary object will log the messages and checkpoint the state to the secondary object periodically. If the primary object fails, the secondary object can take over by way of a client executing a few operations to change the secondary object's mode to primary. Following the style of COSS, we define four interfaces and provide class implementations that can help programmers write programs with fault-tolerant capability. The whole model has been implemented on Orbix, which is a full implementation of CORBA specification.