Self-Optimization of Internet Services with Dynamic Resource Provisioning

Self-optimization through dynamic resource provisioning is an appealing approach to tackle load variation in Internet services. It allows to assign or release resources to/from Internet services according to the varying load. However, dynamic resource provisioning raises several challenges among which: (i) How to plan a good capacity of an Internet service, i.e.~a necessary and sufficient amount of resource to handle the Internet service workload, (ii) How to manage both gradual load variation and load peaks in Internet services, (iii) How to prevent system oscillations in presence of potentially concurrent dynamic resource provisioning, and (iv) How to provide generic self-optimization that applies to different Internet services such as e-mail services, streaming servers or e-commerce web systems. This paper precisely answers these questions. It presents the design principles and implementation details of a self-optimization autonomic manager. It describes the results of an experimental evaluation of the self-optimization manager with a realistic e-commerce multi-tier web application running in a Linux cluster of computers. The experimental results show the usefulness of self-optimization in terms of end-user's perceived performance and system's operational costs, with a negligible overhead

Privacy self-regulation and the changing role of the state: from public law to social and technical mechanisms of governance

This paper provides a structured overview of different self-governance mechanisms for privacy and data protection in the corporate world, with a special focus on Internet privacy. It also looks at the role of the state, and how it has related to privacy self-governance over time. While early data protection started out as law-based regulation by nation-states, transnational self-governance mechanisms have become more important due to the rise of global telecommunications and the Internet. Reach, scope, precision and enforcement of these industry codes of conduct vary a lot. The more binding they are, the more limited is their reach, though they - like the state-based instruments for privacy protection - are becoming more harmonised and global in reach nowadays. These social codes of conduct are developed by the private sector with limited participation of official data protection commissioners, public interest groups, or international organisations. Software tools - technical codes - for online privacy protection can give back some control over their data to individual users and customers, but only have limited reach and applications. The privacy-enhancing design of network infrastructures and database architectures is still mainly developed autonomously by the computer and software industry. Here, we can recently find a stronger, but new role of the state. Instead of regulating data processors directly, governments and oversight agencies now focus more on the intermediaries - standards developers, large software companies, or industry associations. And instead of prescribing and penalising, they now rely more on incentive-structures like certifications or public funding for social and technical self-governance instruments of privacy protection. The use of technology as an instrument and object of regulation is thereby becoming more popular, but the success of this approach still depends on the social codes and the underlying norms which technology is supposed to embed. --

Cross-Layer Routing Based on Semantic Web Services Discovery with Energy Evaluation and Optimization in MANET

The web services discovery process in mobile adhoc networks is considered as a very difficult challenge due to the continuous change in the topology of the network and also the lack of a fixed central directory for publishing web services. Several approaches have been proposed which are based on either keywords or identifiers representing the service to be searched or by using a specific scenario of discovery. All of those proposed solutions try to respect the constraints of ad hoc networks such as energy, bandwidth, throughput ... etc. In this paper we present our new proposed model for measuring the cost of the overall energy consumption in ad hoc networks depending on the web services discovery protocols. We also present a new optimized web services discovery protocol in MANET based on cross_layer routing techniques with the dissemination in the routing process at the same time the semantic web services information and a Discovery_Diameter parameter that we have proposed to limit the area of discovery in the network. Finally, we present simulation results of our defined approach showing a significant optimization of the energy consumption level and the average throughput

Curriculum Vitae of Prof Tebello Nyokong (OMB)

Department of Science and Technology (DST) and National Research Foundation (NRF) Professor of Medicinal Chemistry and Nanotechnology and Distinguished Professor of Chemistry at Rhodes University

RFaaS: RDMA-Enabled FaaS Platform for Serverless High-Performance Computing

The rigid MPI programming model and batch scheduling dominate high-performance computing. While clouds brought new levels of elasticity into the world of computing, supercomputers still suffer from low resource utilization rates. To enhance supercomputing clusters with the benefits of serverless computing, a modern cloud programming paradigm for pay-as-you-go execution of stateless functions, we present rFaaS, the first RDMA-aware Function-as-a-Service (FaaS) platform. With hot invocations and decentralized function placement, we overcome the major performance limitations of FaaS systems and provide low-latency remote invocations in multi-tenant environments. We evaluate the new serverless system through a series of microbenchmarks and show that remote functions execute with negligible performance overheads. We demonstrate how serverless computing can bring elastic resource management into MPI-based high-performance applications. Overall, our results show that MPI applications can benefit from modern cloud programming paradigms to guarantee high performance at lower resource costs

Privacy self-regulation and the changing role of the state : from public law to social and technical mechanisms of governance

This paper provides a structured overview of different self-governance mechanisms for privacy and data protection in the corporate world, with a special focus on Internet privacy. It also looks at the role of the state, and how it has related to privacy selfgovernance over time. While early data protection started out as law-based regulation by nation-states, transnational self-governance mechanisms have become more important due to the rise of global telecommunications and the Internet. Reach, scope, precision and enforcement of these industry codes of conduct vary a lot. The more binding they are, the more limited is their reach, though they – like the state-based instruments for privacy protection – are becoming more harmonised and global in reach nowadays. These “social codes” of conduct are developed by the private sector with limited participation of official data protection commissioners, public interest groups, or international organisations. Software tools - “technical codes” - for online privacy protection can give back some control over their data to individual users and customers, but only have limited reach and applications. The privacy-enhancing design of network infrastructures and database architectures is still mainly developed autonomously by the computer and software industry. Here, we can recently find a stronger, but new role of the state. Instead of regulating data processors directly, governments and oversight agencies now focus more on the intermediaries – standards developers, large software companies, or industry associations. And instead of prescribing and penalising, they now rely more on incentive-structures like certifications or public funding for social and technical self-governance instruments of privacy protection. The use of technology as an instrument and object of regulation is thereby becoming more popular, but the success of this approach still depends on the social codes and the underlying norms which technology is supposed to embed

Adopting collaborative planning for redevelopment of built environment as a means for capacity building of the urban poor

The research examines opportunities for capacity building of the urban poor through redevelopment interventions in their built environment. It investigates whether community participation and collaborative planning strategies applied for built environment redevelopment could lead to capacity building of the urban poor; and how the success of these approaches could be measured. The intention is to determine whether the extent of capacity building achieved within specific projects that are hailed as successful can be effectively measured

A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing

Data Grids have been adopted as the platform for scientific communities that need to share, access, transport, process and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. In this paper, we discuss the key concepts behind Data Grids and compare them with other data sharing and distribution paradigms such as content delivery networks, peer-to-peer networks and distributed databases. We then provide comprehensive taxonomies that cover various aspects of architecture, data transportation, data replication and resource allocation and scheduling. Finally, we map the proposed taxonomy to various Data Grid systems not only to validate the taxonomy but also to identify areas for future exploration. Through this taxonomy, we aim to categorise existing systems to better understand their goals and their methodology. This would help evaluate their applicability for solving similar problems. This taxonomy also provides a "gap analysis" of this area through which researchers can potentially identify new issues for investigation. Finally, we hope that the proposed taxonomy and mapping also helps to provide an easy way for new practitioners to understand this complex area of research.Comment: 46 pages, 16 figures, Technical Repor

Performance analysis and improvement of InfiniBand networks. Modelling and effective Quality-of-Service mechanisms for interconnection networks in cluster computing systems.

The InfiniBand Architecture (IBA) network has been proposed as a new industrial standard with high-bandwidth and low-latency suitable for constructing high-performance interconnected cluster computing systems. This architecture replaces the traditional bus-based interconnection with a switch-based network for the server Input-Output (I/O) and inter-processor communications. The efficient Quality-of-Service (QoS) mechanism is fundamental to ensure the import at QoS metrics, such as maximum throughput and minimum latency, leaving aside other aspects like guarantee to reduce the delay, blocking probability, and mean queue length, etc. Performance modelling and analysis has been and continues to be of great theoretical and practical importance in the design and development of communication networks. This thesis aims to investigate efficient and cost-effective QoS mechanisms for performance analysis and improvement of InfiniBand networks in cluster-based computing systems. Firstly, a rate-based source-response link-by-link admission and congestion control function with improved Explicit Congestion Notification (ECN) packet marking scheme is developed. This function adopts the rate control to reduce congestion of multiple-class traffic. Secondly, a credit-based flow control scheme is presented to reduce the mean queue length, throughput and response time of the system. In order to evaluate the performance of this scheme, a new queueing network model is developed. Theoretical analysis and simulation experiments show that these two schemes are quite effective and suitable for InfiniBand networks. Finally, to obtain a thorough and deep understanding of the performance attributes of InfiniBand Architecture network, two efficient threshold function flow control mechanisms are proposed to enhance the QoS of InfiniBand networks; one is Entry Threshold that sets the threshold for each entry in the arbitration table, and other is Arrival Job Threshold that sets the threshold based on the number of jobs in each Virtual Lane. Furthermore, the principle of Maximum Entropy is adopted to analyse these two new mechanisms with the Generalized Exponential (GE)-Type distribution for modelling the inter-arrival times and service times of the input traffic. Extensive simulation experiments are conducted to validate the accuracy of the analytical models