Cluster computing is excellent for parallel computation. It has become increasingly popular. In cluster computing, a service level agreement (SLA) is a set of quality of services (QoS) and a fee agreed between a customer and an application service provider. It plays an important role in an e-business application. An application service provider uses a set of cluster computing resources to suppo...

In this paper we present SALMon, a tool assessing the satisfaction of service level agreement (SLA) clauses by service-oriented systems. SALMon itself is organized as a service-oriented system that offers two kind of services: 1) the Monitor service that measures the values in execution time of dynamic quality attributes (like response time or availability), and 2) the Analyzer service that det...

While the Internet and the World-Wide-Web (WWW)-based online services expand at an unprecedented pace, the Web users are still experiencing a high level of unavailability. Paralleling the effort of identifying the failure-recovery behaviors of the underlying supporting infrastructure, attention has also been paid to Web users’ behaviors. However, a link between the two research directions seems...

Due to the increasing need of highly dependable services in Service-Oriented Architectures (SOA), service-level agreements include more and more frequently such non-functional aspects as security, safety, availability, reliability, etc. Whenever a service can no longer be provided with the required QoS, the service requester needs to switch dynamically to a new service having adequate service p...

Mobile Ad Hoc Networks (MANETs) offer quick and easy network deployment in situations where it is not possible otherwise and they can be used to provide mobile users with a temporary infrastructure to use services in the absence of fixed infrastructure. Nodes in MANETs are free to move and organize themselves in an arbitrary fashion. The challenging task in such dynamic environments is how to i...

Workstations typically depend on remote servers accessed over a network for such services as mail, printing, storing files, booting, and time. The availability of these remote services has a major impact on the usability of the workstation. Availability can be increased by replicating the servers. In the Echo distributed file system at DEC SRC, two different replication techniques are employed,...

In the application domain of online information services such as online census information, health records and real-time stock quotes, there are at least two fundamental challenges: the protection of users’ privacy and the assurance of service availability. We present a fault-tolerant scheme for private information retrieval (FT-PIR) that protects users’ privacy and ensures service provision in...

Trust management is one of the most challenging issues in the emerging cloud computing. Although many approaches have been proposed recently for trust management in cloud environments, not much attention has been given to determining the credibility of trust feedbacks. Moreover, the dynamic nature of cloud environments makes guaranteeing the availability of trust management services a difficult...

From the results of a web survey we carried out in 2006, the main challenge in IT change management from a change manager’s perspective was identified as planning and scheduling of changes. This paper begins to address this problem by taking business considerations into account; this is done through a business-driven IT management (BDIM) approach. A reference architecture that follows BDIM prin...