Group-oriented multicast protocols that provide message ordering and delivery guarantees are becoming increasingly important in distributed system design. However, despite the large number of such protocols, little analytical work has been done concerning their performance, especially in the presence of message loss. This paper illustrates a method for determining the performability of group-or...

An integral part of the performance modeling process is the specification of the performability measures of interest. The notations proposed for this purpose can be grouped into classes that differ from each other in their expressiveness and usability. Two representative notations are the continuous stochastic reward logic CSRL and the measure specification language MSL. The former is a stochas...

ÐPetri nets represent a useful tool for performance, dependability, and performability analysis of complex systems. Their modeling power can be increased even more if nonexponentially distributed events are considered. However, the inclusion of nonexponential distributions destroys the memoryless property and requires to specify how the marking process is conditioned upon its past history. In t...

Petri nets and Markovian Petri nets are excellent tools for logic and performability system modeling. However, the size of the underlying reachability set is a major limitation in practice. One approach gaining attention among researchers is the use of structured representations, which require us to decompose a net into, or compose a net from, subnets. This paper surveys the stateof-the-art in ...

Behavioral decomposition is a classical modeling ap proach for performability analysis typically resulting in Markov reward models in which the states represent system con gurations and the rewards represent per formance given the system con guration In this report we experimentally investigate ways of obtaining rewards from a performance model We discuss four candidate metrics to determine rew...

This paper deals with the performance analysis of multiple server retrial queueing systems with a finite number of homogeneous sources of calls, where the heterogeneous servers are subject to random breakdowns and repairs. The requests are serviced according to random and fastest free server disciplines. The novelty of this investigation is the different service rates and different service poli...

This thesis studies the effects of latent sector faults on reliability, performance, and combined performability of disk arrays. This is done by developing two novel reliability models that include two fault types: disk unit faults and sector faults. The new reliability models study both hot swap and hot spare approaches in repairing disk unit faults. A traditional analytical method and also a ...

An analytical model is used to investigate the effects of checkpointing on the performance and availability of sequential and parallel applications. Known as Steady-State Performability (SSP), this model provides a probabilistic method for quantifying delivered performance considering failure and recovery. Input parameters describe both the distributed application and the processing environment...

In this tutorial, we discuss several practical issues regarding specification and solution of dependability and performability models. We compare model types with and without rewards. Continuous-time Markov chains (CTMCs) are compared with (continuous-time) Markov reward models (MRMs) and generalized stochastic Petri nets (GSPNs) are compared with stochastic reward nets (SRNs). It is shown that...