In this paper, we propose a data replication algorithm adaptive to unreliable environments. The data replication algorithm, named Adaptive Data Replication (ADR), has already an adaptiveness mechanism encapsulated in its dynamic replica placement strategy. Our extension of ADR to unreliable environments provides a data replication solution that is adaptive both in terms of replica placement and...

The increased using of the Internet and its accelerated growth leads to reduced network bandwidth and the capacity of servers; therefore, the quality of Internet services is unacceptable for users while the efficient and effective delivery of content on the web has an important role to play in improving performance. Content distribution networks were introduced to address this issue. Replicatin...

Open peer-to-peer architectures offer many possibilities for replicating database content, but designers have to deal with problems such as peer churn rates and inherent uncertainty in decision making. The lack of global knowledge of peer characteristics poses the specific problem of reliable peer discovery for database replica placement. This paper describes a self-organising algorithm for gen...

In this paper, we study the replica placement problem on trees and present a constant factor approximation algorithm (with an additional additive constant factor). This improves the best known previous algorithm having an approximation ratio dependent on the maximum degree of the tree. Our techniques also extend to the partial cover version. Our algorithms are based on the LP rounding technique...

Application details uncertain at design time as well as tolerance against permanent resource defects demand flexibility and redundancy. In this context, we present a strategy for placing replicas in embedded point-to-point networks where link as well as node defects may occur at runtime. The proposed strategies for replica placement are based on the partitioning of the network into biconnected ...

The importance of satisfying the availability of service and its data is becoming the most critical factor which decides the successfulness of the Internet-based services and applications. In this work, we take the availability issue into account as a QoS focus, and evaluate the achieved quality of a service by answering the question 'how much the service satisfies the required availability?'. ...

This paper proposes a new replica placement algorithm that expands the exhaustive search limit with reasonable calculation time. It combines a new type of parallel data-flow processor with an architecture tuned for fast calculation. The replica placement problem is to find a replica-server set satisfying service constraints in a content delivery network (CDN). It is derived from the set cover p...

In this paper, we propose the dissemination tree, a dynamic content distribution system built on top of a peer-to-peer location service. We present a replica placement protocol that builds the tree while meeting QoS and server capacity constraints. The number of replicas as well as the delay and bandwidth consumption for update propagation are significantly reduced. Simulation results show that...