This paper provides a review of the components of disaster tolerant computing and communications and reviews the current state in light of recent man-made terrorist events. The paper examines the relationships between disaster tolerant systems, Information Technology (IT) application availability and executive level management visibility necessary for successful system operations in the event o...

Executive Summary The overall concept of Total Cost of Ownership for server clusters has been an important issue within the IT community for many years. Numerous studies and customer experiences have proven that purchase price alone is not an adequate measurement to compare server clusters from various vendors. Other factors, including the costs to manage and maintain the servers, as well as th...

Highly available software systems occasionally need to be updated while avoiding downtime. Dynamic software updates reduce downtime, but still require the system to reach a quiescent state in which a global update can be performed. This can be difficult for multi-threaded systems. We present a novel approach to dynamic updates using firstclass contexts, called Theseus. First-class contexts make...

Availability of business-critical application servers is an issue of paramount importance that has received special attention from the industry and academia. To improve the availability of application servers, we have conducted a study of virtualization technology and software rejuvenation that follows a proactive fault-tolerant approach to counter act the software aging problem. We present Mar...