In systems that use primary-backup replication for fault-tolerance, maintaining system availability after failures refers not just to ensuring the liveness of application functionality at a backup replica but also to ensuring that the state of the promoted backup matches that of the failed primary. Traditionally these availability criteria are realized in middleware through sophisticated algori...

Monitoring the resources of distributed systems is essential to the successful deployment and execution of grid applications, particularly when such applications have welldefined QoS requirements. The dproc system-level monitoring mechanisms implemented for standard Linux kernels have several key components. First, utilizing the familiar /proc filesystem, dproc extends this interface with resou...

To respond effectively in the event of a public health emergency, careful analysis of preparedness plans is essential. This note describes a linear programming model of the Center for Disease Control Strategic National Stockpile (SNS) supply chain for distributing medical supplies under emergency conditions. The purpose of the model is to evaluate the effects that a specified collection of plan...

Many resource sharing scenarios can be modeled as congestion games. A nice property of congestion games is that simple dynamics are guaranteed to converge to Nash equilibria. Loose bounds on the convergence time are known, but exact results are difficult to obtain in general. We investigate congestion games where the resources are homogeneous but can be player-specific. In these games, players ...

We revisit the problem of selecting the suitable server, among a list of replica servers, so as to optimize the response time resulting from the execution of the clients’ requests. Our proposition, presented in this paper, consists in the definition of a function estimating the response time and a method for applying it to different application workloads. The function combines the application d...

When resource consumers select among competing providers based on delayed information, inefficient oscillations in resource utilization can emerge. This paper describes an approach, based on selective stochastic resource request rejection, for dealing with this emergent dysfunction.

The general timetabling problem is an assignment of activ ities to xed time intervals adhering to a prede ned set of resource availabilities Timetabling problems are di cult to solve and can be ex tremely time consuming without some computer assistance In this paper the application of constraint based reasoning to timetable generation is examined Speci cally we consider how a timetabling proble...

The process of generating optimized schedules for construction projects is a very time-consuming. For each construction task several execution restrictions, conditions and requirements such as technological dependencies or resource availabilities have to be considered. This leads to a multitude of possible execution orders and consequently to a hard optimization problem. Within this paper the i...