Distributed software is usually structured in layers, with some kind of operational control or user interface tasks as the topmost layer, making requests to various layers of servers. Client Server systems and ODP (Open Distributed Processing) systems such as DCE, ANSA and CORBA are structured this way, as are distributed transaction processing systems. Performance and dependability are the two...

Grid computing is a newly developed technology for complex systems with large-scale resource sharing, wide-area communication, and multi-institutional collaboration. Although the developmental tools and infrastructures for the grid have been widely studied, grid reliability analysis and modeling are not easy because of its largeness, complexity and stiffness. This chapter introduces the grid co...

This paper presents a detailed, but eeciently solv-able model of the N version programming for evaluating the reliability and performability over a mission period. Employing a hierarchical decomposition we reduce the model complexity and provide a modeling framework for evaluating the NVP failure and execution time behavior and the operational environment, as well. The failure and execution rat...

We propose a two-phase methodology for quantifying the performability (performance + availability) of cluster-based Internet services. In the first phase, evaluators use a fault-injection infrastructure to measure the impact of faults on the server’s performance. In the second phase, evaluators use an analytical model to combine an expected fault load with measurements from the first phase to a...

The ever increasing societal demand for the timely availability of newer and feature-rich but highly dependable network-centric applications imposes the need for these applications to be constructed by the composition, assembly and deployment of off-the-shelf infrastructure and domain-specific services building blocks. Service Oriented Architecture (SOA) is an emerging paradigm to build applica...

Telecommunication systems are large and complex, consisting of multiple intelligent modules in shelves, multiple shelves in frames, and multiple frames to compose a single network element. In the availability and performability analysis of such a complex system, combinatorial models are computationally efficient but have limited expressive power. State-based models are expressive but computatio...

Quality attributes, such as performance and dependability of a software-intensive system are constrained by its software architecture. The combined performance and dependability (called performability) effects of an architecture can be evaluated by constructing a performability model that considers the failure/repair behavior and performance attributes of its components, interactions among the ...

Stochastic activity networks (SANs) are a powerful and flexible extension of Petri nets. However, SANs facilities are not enough for modeling and analysis of complex and large-scale systems. In order to provide such high-level modeling facilities, we have defined some new extensions for SANs. We intend to preserve all capabilities of SANs for performance, dependability and performability evalua...

We present a comprehensive methodology for the specification and analysis of critical embedded systems. The methodology is based on an architectural design language that enables modeling of both software and hardware components, timed and hybrid behavior, faulty behavior and degraded modes of operation, error propagation and recovery. The methodology is supported by an integrated platform, impl...