The SCC and the SICSA multi-core challenge

Two phases of the SICSA Multi-core Challenge have gone past. The first challenge was to produce concordances of books for sequences of words up to length N; and the second to simulate the motion of N celestial bodies under gravity. We took both challenges on the SCC, using C and the Linux Shell. This paper is an account of the experiences gained. It also gives a shorter account of the performance of other systems on the same set of problems, as they provide benchmarks against which the SCC performance can be compared with

A trustworthy mobile agent infrastructure for network management

Despite several advantages inherent in mobile-agent-based approaches to network management as compared to traditional SNMP-based approaches, industry is reluctant to adopt the mobile agent paradigm as a replacement for the existing manager-agent model; the management community requires an evolutionary, rather than a revolutionary, use of mobile agents. Furthermore, security for distributed management is a major concern; agent-based management systems inherit the security risks of mobile agents. We have developed a Java-based mobile agent infrastructure for network management that enables the safe integration of mobile agents with the SNMP protocol. The security of the system has been evaluated under agent to agent-platform and agent to agent attacks and has proved trustworthy in the performance of network management tasks

Saber: window-based hybrid stream processing for heterogeneous architectures

Modern servers have become heterogeneous, often combining multicore CPUs with many-core GPGPUs. Such heterogeneous architectures have the potential to improve the performance of data-intensive stream processing applications, but they are not supported by current relational stream processing engines. For an engine to exploit a heterogeneous architecture, it must execute streaming SQL queries with sufficient data-parallelism to fully utilise all available heterogeneous processors, and decide how to use each in the most effective way. It must do this while respecting the semantics of streaming SQL queries, in particular with regard to window handling. We describe SABER, a hybrid high-performance relational stream processing engine for CPUs and GPGPUs. SABER executes windowbased streaming SQL queries in a data-parallel fashion using all available CPU and GPGPU cores. Instead of statically assigning query operators to heterogeneous processors, SABER employs a new adaptive heterogeneous lookahead scheduling strategy, which increases the share of queries executing on the processor that yields the highest performance. To hide data movement costs, SABER pipelines the transfer of stream data between different memory types and the CPU/GPGPU. Our experimental comparison against state-ofthe-art engines shows that SABER increases processing throughput while maintaining low latency for a wide range of streaming SQL queries with small and large windows sizes

Making sense of maritime supply chain: a relationship marketing approach

Building a relationship with the maritime supply chain partners is considered imperative for organisations to survive and remain competitive. Yet, several studies that examined the maritime supply chain have not adequately explored nor assessed the relationship constructs that impacts maritime supply chain performance. This study intends to fill this gap and ascertain the influence that certain relationship elements have on the maritime supply chain performance. The study is solely a desk research. After providing a general overview of maritime supply chain and its structure, relationship marketing paradigm and relationship constructs, this study examines the influence that the identified relationship constructs (i.e. trust, commitment and satisfaction) has on supply chain performance. The study asserts that the present of the identified relationship constructs (i.e. trust, commitment and satisfaction) among supply chain partners will influence supply chain performance positively. Hence, building a successful long-term relationship among maritime supply chain partners requires an understanding of these key relationship constructs

Supporting novel home network management interfaces with Openflow and NOX

The Homework project has examined redesign of existing home network infrastructures to better support the needs and requirements of actual home users. Integrating results from several ethnographic studies, we have designed and built a home networking platform providing detailed per-flow measurement and management capabilities supporting several novel management interfaces. This demo specifically shows these new visualization and control interfaces, and describes the broader benefits of taking an integrated view of the networking infrastructure, realised through our router's augmented measurement and control APIs. Aspects of this work have been published: the Homework Database in Internet Management (IM) 2011 and implications of the ethnographic results are to appear at the SIGCOMM W-MUST workshop 2011. Separate, more detailed expositions of the interface elements and system performance and implications are currently under submission at other venues. A partial code release is already available and we anticipate fuller public beta release by Q4 2011

Supporting novel home network management interfaces with Openflow and NOX

The Homework project has examined redesign of existing home network infrastructures to better support the needs and requirements of actual home users. Integrating results from several ethnographic studies, we have designed and built a home networking platform providing detailed per-flow measurement and management capabilities supporting several novel management interfaces. This demo specifically shows these new visualization and control interfaces, and describes the broader benefits of taking an integrated view of the networking infrastructure, realised through our router's augmented measurement and control APIs. Aspects of this work have been published: the Homework Database in Internet Management (IM) 2011 and implications of the ethnographic results are to appear at the SIGCOMM W-MUST workshop 2011. Separate, more detailed expositions of the interface elements and system performance and implications are currently under submission at other venues. A partial code release is already available and we anticipate fuller public beta release by Q4 2011

UDRF: Multi-Resource Fairness for Complex Jobs with Placement Constraints

© 2015 IEEE.In this paper, we study the problem of multi-resource fairness in systems with multiple users. Each user requires to run one or more complex jobs that consist of multiple interconnected tasks. A job is considered finished when all its corresponding tasks have been executed in the system. Tasks can have different resource requirements. Because of special demands on particular hardware or software, tasks can have placement constraints limiting the type of machines they can run on. We develop User-Dependence Dominant Resource Fairness (UDRF), a generalized version of max-min fairness that combines graph theory and the notion of dominant resource shares to ensure multi- resource fairness between users with complex jobs. UDRF satisfies several desirable properties including strategy proofness, which ensures that users do not benefit from misreporting their true resource demands. We propose an offline algorithm that computes optimal UDRF allocation while the scheduling process can be to be decentralize across multiple schedulers. But optimality comes at a cost, especially for systems where schedulers need to make thousands of online scheduling decisions per second. Therefore, we develop a lightweight online algorithm that closely approximates UDRF. Large-scale simulations driven by Google cluster- usage traces show that UDRF achieves better resource utilization and throughput compared to the current state-of-the-art in multi-resource fair allocation

An Information Plane Architecture Supporting Home Network Management

Home networks have evolved to become small-scale versions of enterprise networks. The tools for visualizing and managing such networks are primitive and continue to require networked systems expertise on the part of the home user. As a result, non-expert home users must manually manage non-obvious aspects of the network - e.g., MAC address filtering, network masks, and firewall rules, using these primitive tools. The Homework information plane architecture uses stream database concepts to generate derived events from streams of raw events. This supports a variety of visualization and monitoring techniques, and also enables construction of a closed-loop, policy-based management system. This paper describes the information plane architecture and its associated policy-based management infrastructure. Exemplar visualization and closed-loop management applications enabled by the resulting system (tuned to the skills of non-expert home users) are discussed. © 2011 IEEE.Accepted versio

Management of Networked Sensor Systems

The ready availability of integrated circuits for sensing (MEMS), processing and wireless communication has resulted in burgeoning interest in the design, implementation, deployment, and operation of environmental sensor networks. The maintenance and control of such systems is essential to ensure efficient use of resources for appropriate information gathering and processing; since most of these networks must (of necessity) operate in an unsupervised manner, these systems must also recover from partial failure or changes in the sensed environment. Currently, management functionality is inextricably intertwined with application, operating system, and/or networking components. Additionally, despite the existence of management frameworks for well-resourced, wireline networks, there is no reason to believe a priori that such frameworks will apply to the resource-constrained environments of typical environmental sensor networks. We survey network management functionality in existing sensor networks (focussed on battery-powered, wireless sensors that are static or move infrequently). This survey yields a set of dimensions for the different categories of management functionality implemented in the surveyed systems: deployment, diagnostics, application software, bandwidth, energy, and security management. We then discuss how use of such a classification scheme can aid the structured development of the management aspects of future sensor network systems

Proactive vs Reactive Routing for Wireless Sensor Networks

Sensor network routing protocols must ensure the stability of the network infrastructure under varying network dynamics. Recovery from changes or failures is necessary to guarantee the availability of collection or dissemination paths. Routing protocols may react to path requests or proactively maintain a connected graph. Although functionally equivalent, proactive and reactive protocols are associated with different costs, in terms of resource overhead (e.g. energy or bandwidth) and non-functional guarantees (e.g. end-to-end delay, or time to repair). The protocol of choice must satisfy the system objectives, yet it should not require excessive resources. We study the behavior of proactive and reactive routing schemes, using prototype TinyOS implementations of the OSPF and AODV protocols, respectively. Simulation results show that there exist regions in the time-to-repair x overhead space where reactive protocols are preferred over proactive and vice versa; the proactive preference region grows as the number of simultaneous flows increases