In this work, we present a first effort at quantitatively comparing the strengths and limitations of various intrusion-tolerant server architectures. We study four representative architectures, and use stochastic models to quantify the costs and benefits of each from both the performance and dependability perspectives. We present results characterizing throughput and availability, the effective...

This paper describes the tool CASPA, a new performance evaluation tool which is based on a Markovian stochastic process algebra. CASPA uses multi-terminal binary decision diagrams (MTBDD) to represent the labelled continuous time Markov chain (CTMC) underlying a given process algebraic specification. All phases of modelling, from model construction to numerical analysis and measure computation,...

At present, many open source software are developed in all parts of the world, i.e., Firefox, Apache HTTP server, Linux, Android, etc. In particular, a cloud computing is an attracting attention as network service to share the computing resources, i.e., networks, servers, storage, applications, and services. This paper focuses on a cloud computing environment by using open source software such ...

Symbolic data structures, such as binary decision diagrams (BDD) [1] and variants thereof have proved to be suitable for the efficient generation and compact representation of very large state spaces and transition systems. The key to such compact representation is the exploitation of the compositional structure of a given specification [2], [3]. It is also known that in addition to functional ...

Markov chains (and their extensions with rewards) have been widely used to determine performance, dependability and performability characteristics of computer communication systems, such as throughput, delay, mean time to failure, or the probability to accumulate at least a certain amount of reward in a given time. Due to the rapidly increasing size and complexity of systems, Markov chains and ...

Welcome to this special issue of Performance Evaluation, presenting selected papers of the recent 11th International Conference on Modelling Tools and Techniques for Computer Performance Evaluation (TOOLS 2000) and the Fourth IEEE International Performance and Dependability Symposium (IPDS 2000), which were both hosted by Motorola in their Galvin Center in Schaumburg, a suburb of Chicago, 27–30...

The ever-increasing popularity of peer-to-peer (P2P) systems provides a strong motivation for designing a dependable P2P system. Dependability in P2P systems can be viewed from two different perspectives, namely system reliability (the availability of the individual peers) and system performance (data availability). This paper looks at dependability from the viewpoint of system performance and ...