Designing autonomic fault responses is difficult, particularly in large-scale systems, as there is no single 'perfect' fault mitigation response to a given failure. The design of appropriate mitigation actions depend upon the goals and state of the application and environment. Strict time deadlines in real-time systems further exacerbate this problem. Any autonomic behavior in such systems must not only be functionally correct but should also conform to properties of liveness, safety and bounded time responsiveness. This paper details a realtime fault-tolerant framework, which uses a reflex and healing architecture to provide fault mitigation capabilities for large-scale real-time systems. At the heart of this architecture is a real-time reflex engine, which has a state-based failure management logic that can respond to both event-and time-based triggers. We also present a semantic domain for verifying properties of systems, which use this framework of real-time reflex engines.A. Dubey (B) · S. Nordstrom · T. Keskinpala · S. Neema · Lastly, a case study, which examines the details of such an approach, is presented.
In Model Integrated Computing, it is often desirable to evaluate different design alternatives as they relate to issues of scalability. A typical approach to address scalability is to create a base model that captures the key interactions of various components (i.e., the essential properties and connections among modeling entities). A collection of base models can be adorned with necessary information to characterize their replication. In current practice, replication is accomplished by scaling the base model manually. This is a time-consuming process that can also represent a source of error, especially when there are deep interactions between model components. As an alternative to the manual process, this paper presents the idea of a replicator, which is a model transformation that expands the number of elements from the base model, and also makes the correct connections among the generated modeling elements. The paper motivates the need for replicators through case studies taken from models that support different domains.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.