An externalized infrastructure for self-healing systems

Software architecture descriptions can play a wide variety of roles in the software lifecycle, from requirements specification, to logical design, to implementation architectures. In addition, execution architectures can be used both to constrain and enhance the functionality of running systems, e.g. security architectures and debugging architectures. Along with others from DARPA's DASADA program we proposed an execution infrastructure for so-called self-healing, self-adaptive systems - systems that maintain a particular level of healthiness or quality of service (QoS). This externalized infrastructure does not entail any modification of the target system - whose health is to be maintained. It is driven by a reflective model of the target system's operation to determine what aspects can be changed to effect repair. We present that infrastructure along with an example implemented in accord with it.