Quantifying the Overall Impact of Caching and Replication in the Web

This paper discusses the benefits and drawbacks of caching and replication strategies in the WWW with respect to the Internet infrastructure. Bandwidth consumption, latency, and overall error rates are considered to be most important from a network point of view. The dependencies of these values with input parameters like degree of replication, document popularity, actual cache hit rates, and error rates are highlighted. In order to determine the influence of different caching and replication strategies on the behavior of a single proxy server with respect to these values, trace-based simulations are used. Since the overall effects of such strategies can hardly be decided with this approach alone, a mathematical model has been developed to deal with their influence on the network as a whole. Together, this two-tiered approach permits us to propose quantitative assessments on the influence different caching and replication proposals (are going to) have on the Internet infrastructure. 1..

Quantifying the Overall Impact of Caching and Replication in the Web

This paper discusses the benefits and drawbacks of caching and replication strategies in the WWW with respect to the Internet infrastructure. Bandwidth consumption, latency, and overall error rates are considered to be most important from a network point of view. The dependencies of these values with input parameters like degree of replication, document popularity, actual cache hit rates, and error rates are highlighted. In order to determine the influence of different caching and replication strategies on the behavior of a single proxy server with respect to these values, trace-based simulations are used. Since the overall effects of such strate- gies can hardly be decided with this approach alone, a mathematical model has been developed to deal with their influence on the network as a whole. Together, this two-tiered approach permits us to propose quantita- tive assessments on the influence different caching and replication proposals (are going to) have on the Inter- net infrastructure

S.: Customization of system software for large-scale embedded applications

Operating systems are one of the most frequently reused software components: almost every application is sitting on top of an OS which establishes the required runtime platform. It is claimed that bridging the gap between a high level application design and the OS is a costly process, especially in distributed systems. A conceptual framework is presented which aims at supporting the automatic generation of distributed runtime platforms from high-level application designs. It is based on the generic layout of operating system services, their extended description including nonfunctional properties, as well as analysis and development tools which filter out OS requirements from the applicatio

Quantifying the Overall Impact of Caching and Replication in the Web

This paper discusses the benefits and drawbacks of caching and replication strategies in the WWW with respect to the Internet infrastructure. Bandwidth consumption, latency, and overall error rates are considered to be most important from a network point of view. The dependencies of these values with input parameters like degree of replication, document popularity, actual cache hit rates, and error rates are highlighted. In order to determine the influence of different caching and replication strategies on the behavior of a single proxy server with respect to these values, trace-based simulations are used. Since the overall effects of such strategies can hardly be decided with this approach alone, a mathematical model has been developed to deal with their influence on the network as a whole. Together, this two-tiered approach permits us to propose quantitative assessments on the influence different caching and replication proposals (are going to) have on the Internet infrastructure

Developing a Collaborative and Autonomous Training and Learning Environment for Hybrid Wireless Networks

Abstract ⎯ With larger memory capacities and the ability to link into wireless networks, more and more students uses palmtop and handheld computers for learning activities. However, existing software for Web-based learning is not well-suited for such mobile devices, both due to constrained user interfaces as well as communication effort required. A new generation of applications for the learning domain that is expicitly designed to work on these kinds of small mobile devices has to be developed. For this purpose, we introduce CARLA, a cooperative learning system that is designed to act in hybrid wireless networks. As a cooperative environment, CARLA aims at disseminating teaching material, notes, and even components of itself through both fixed and mobile networks to interested nodes. Due to the mobility of nodes, CARLA deals with upcoming problems such as network partitions and synchronization of teaching material, resource dependencies, and time constraints

Interactive libraries - automatic guidance for using software components

The employment of ready-made libraries in a large software project is mandatory for its successful, timely and profitable realization. Yet it does not come for free. On the one hand, for any library, there is a time-consuming learning phase necessary before it can be used correctly. On the other hand, the employment of libraries requires developers to waste expensive time performing undemanding routine tasks, e.g. adapting the calls to library primitives to the context in the application code. The concept of Interactive Libraries addresses both problem areas. Semantic aspects of the library services are made explicit and presented to the application developer by a support tool that also knows the syntax of the service primitives. This combination offers help that is exactly tailored to the current usage context of the library. Time-consuming browsing of manuals is not necessary any more. (orig.)SIGLEAvailable from TIB Hannover: RR 7261(96,12) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman