Topology Agnostic Methods for Routing, Reconfiguration and Virtualization of Interconnection Networks

Modern computing systems, such as supercomputers, data centers and multicore chips, generally require efficient communication between their different system units; tolerance towards component faults; flexibility to expand or merge; and a high utilization of their resources. Interconnection networks are used in a variety of such computing systems in order to enable communication between their diverse system units. Investigation and proposal of new or improved solutions to topology agnostic routing and reconfiguration of interconnection networks are main objectives of this thesis. In addition, topology agnostic routing and reconfiguration algorithms are utilized in the development of new and flexible approaches to processor allocation. The thesis aims to present versatile solutions that can be used for the interconnection networks of a number of different computing systems. No particular routing algorithm was specified for an interconnection network technology which is now incorporated in Dolphin Express. The thesis states a set of criteria for a suitable routing algorithm, evaluates a number of existing routing algorithms, and recommend that one of the algorithms – which fulfils all of the criteria – is used. Further investigations demonstrate how this routing algorithm inherently supports fault-tolerance, and how it can be optimized for some network topologies. These considerations are also relevant for the InfiniBand interconnection network technology. Reconfiguration of interconnection networks (change of routing function) is a deadlock prone process. Some existing reconfiguration strategies include deadlock avoidance mechanisms that significantly reduce the network service offered to running applications. The thesis expands the area of application for one of the most versatile and efficient reconfiguration algorithms available in the literature, and proposes an optimization of this algorithm that improves the network service offered to running applications. Moreover, a new reconfiguration algorithm is presented that supports a replacement of the routing function without causing performance penalties. Processor allocation strategies that guarantee traffic-containment commonly pose strict requirements on the shape of partitions, and thus achieve only a limited utilization of a system’s computing resources. The thesis introduces two new approaches that are more flexible. Both approaches utilize the properties of a topology agnostic routing algorithm in order to enforce traffic-containment within arbitrarily shaped partitions. Consequently, a high resource utilization as well as isolation of traffic between different partitions is achieved

Algorithm Based Fault Tolerance in Massively Parallel Systems

An A complex computer system consists of billions of transistors, miles of wires, and many interactions with an unpredictable environment. Correct results must be produced despite faults that dynamically occur in some of these components. Many techniques have been developed for fault tolerant computation. General purpose methods are independent of the application, yet incur an overhead cost which may be unacceptable for massively parallel systems. Algorithm-specific methods, which can operate at lower cost, are a developing alternative [1, 72]. This paper first reviews the general-purpose approach and then focuses on the algorithm-specific method, with an eye toward massively parallel processors. Algorithm-based fault tolerance has the attraction of low overhead; furthermore it addresses both the detection and also the correction problems. The principle is to build low-cost checking and correcting mechanism based exclusively on the redundancies inherent in the system

Diseño de mecanismos eficientes para la gestión de subredes infiniband

El objetivo principal de esta tesis doctoral es contribuir al desarrollo de mecanismos de asimilación de cambios toplogicos para la arquitectura de red infiniband. En una primera fase, se ha diseñado y evaluado un primer prototipo de mecanismo de gestión. Su evaluación nos ha permitido identificar los principales cuellos de botella en el proceso de adaptación al cambio. A continuación, se han propuesto mecanismos optimizados para cada una de las tareas involucradas en dicho proceso: la detección del cambio topológico, la adquisición de la nueva topología de la red, el cómputo de nuevas rutas y la distribución de tables de encaminamiento actualizadas a los conmutadores de la red. El resultado es un mecanismo de gestión totalmente compatible con la especificación de infiniband, fácilmente implementable en sistemas comerciales, y casi transparente desde el punto de vista de las aplicaciones a las que da servicio la red

Efficient Algorithms for Large-Scale Image Analysis

This work develops highly efficient algorithms for analyzing large images. Applications include object-based change detection and screening. The algorithms are 10-100 times as fast as existing software, sometimes even outperforming FGPA/GPU hardware, because they are designed to suit the computer architecture. This thesis describes the implementation details and the underlying algorithm engineering methodology, so that both may also be applied to other applications

Wings in Orbit: Scientific and Engineering Legacies of the Space Shuttle, 1971-2010

The Space Shuttle is an engineering marvel perhaps only exceeded by the station itself. The shuttle was based on the technology of the 1960s and early 1970s. It had to overcome significant challenges to make it reusable. Perhaps the greatest challenges were the main engines and the Thermal Protection System. The program has seen terrible tragedy in its 3 decades of operation, yet it has also seen marvelous success. One of the most notable successes is the Hubble Space Telescope, a program that would have been a failure without the shuttle's capability to rendezvous, capture, repair, as well as upgrade. Now Hubble is a shining example of success admired by people around the world. As the program comes to a close, it is important to capture the legacy of the shuttle for future generations. That is what "Wings In Orbit" does for space fans, students, engineers, and scientists. This book, written by the men and women who made the program possible, will serve as an excellent reference for building future space vehicles. We are proud to have played a small part in making it happen. Our journey to document the scientific and engineering accomplishments of this magnificent winged vehicle began with an audacious proposal: to capture the passion of those who devoted their energies to its success while answering the question "What are the most significant accomplishments?" of the longestoperating human spaceflight program in our nation s history. This is intended to be an honest, accurate, and easily understandable account of the research and innovation accomplished during the era

Large space structures and systems in the space station era: A bibliography with indexes

Bibliographies and abstracts are listed for 1219 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1990 and December 31, 1990. The purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems

Renegotiating communal autonomy: communal land rights and liberal land reform on the Bolivian altiplano: Carangas, 1860-1930

This dissertation is the result of a detailed analysis of the local dynamics generated in the context of an anti-corporatist land reform in a rural region marked by a strong communal control over land. The presented case study is informed by a broader analytical framework that allows for a critical assessment of peripheral agency within a globalizing world. With this research, I aim to contribute to a more comprehensive understanding of global-local interactions in which local actors, and particularly rural communities, creatively re-negotiate the terms of their participation and autonomy in the face of state- and market-driven integration processes. This ambition leads to the question of how trajectories of rural transition are shaped by the course of world-systemic expansion and, the other way around, how processes of globalization are “fuelled” by local dynamics of rural change. Do these local-global entanglements constellate a more homogeneous world, or do they feed new trends of ? My assessment of that question seeks to grasp how autonomous spaces for communal organization have been asserted or enclosed throughout the cycles of world-systemic contraction and expansion. In view of the historical oscillations in the erosion and renewal of such spaces, it interrogates the assets and potentials but also the vulnerabilities of communal agency. I address the question on rural change and communal autonomy from the angle of land rights and the imposition of standardized land rights. This process of commodification will be specified for the rural Andes, where the outcome of centuries-long processes of colonial exploitation and post-colonial extractivism entails a remarkable (yet over the centuries increasingly more defied) “margin” for the safeguarding of communal land control. Why could such rights be preserved in certain regions? How were these rights safeguarded throughout cycles of land rights commodification? What implications did this have on the longer term? I confine my examination of these questions to Bolivia’s first land reform project launched by under the name of Exvinculación, referring to the Alienation Act of 1874. This reform emblematizes a longer and conflictive process of liberal legislation and rural transformation that subjected communal autonomy and land rights security to an enclosure operation. The central story of this research, however, tells more about the enclosure’s standstill rather than its advance. The province of Carangas, entirely located on the altiplano (Andean High Plateau), was one of the few rural zones where the land reform made no headway. While this is mainly explained by the region’s protracted marginalization and its little attractive soil for agricultural entrepreneurs, the premise of my research urges to look beyond ecological and demographic factors. The two guiding questions of my enquiry are why and how the imposed land rights reorganization of customary land systems and the related break-up of communities was kept at bay in Carangas; and what impact this had on social power relations on the long term. This assessment is based on extensive archive research as well as field work in several villages of the former province. This combination of methods allowed me to dissect the most local levels of organizing life in Carangas. The dissertation is structured by three parts. In the first part, I present the theoretical framework of my research, constructed around the notion of “frontier” and “frontier zones”. On basis of these building blocks, the first chapter proposes a “frontier perspective” as an approach towards local-global interactions in terms of a dynamic process of incorporation that has a spatial repercussion, reflected in the formation of a “frontier zone” where differently organized groups and regions come into sustained contact. The second chapter relates the movement of frontiers and the creation of frontier zones to the historical incorporation trajectory of the rural Andes and detects the “communal” as the essential framework for strategies to enter in “negotiation” with state and market actors. This “negotiated peripherality” is based on the determination and ability of community-bound actors to participate in broader structures for exchange and regulation and simultaneous secure a margin for communal modes of production and governance. In the second part of the dissertation I reconstruct the particular setting of this incorporation process. Chapter three gives insight into how rural life in Carangas is organized within a social agro-pastoralist framework on basis of land, labour and livestock management, and how people and resources are brought into circulation through a “complex exchange chain.” Chapter four assesses how local production, exchange and regulation was bound by a fiscal-legal land system, local practices and interregional patterns for exchange and mobility, and elite intermediation. The third and last part comprises the case study, focusing on the land reform experience of the communities of the Carangas province between 1860 and 1930. Chapter five explains how, nurtured by new liberal ideas on land and property, a disentailment legislation was debated and designed. While envisioning a capitalist transition of community-bound indigenous population into a smallholder class, the reform process rather nurtured the expansion of the hacienda complex, meanwhile triggering a strong reaction on part of the communities. Through a threefold resistance strategy of legal action, political lobbying and violent confrontation, they obtained important concessions for communal land tenure, thereby destabilizing the legislation. The last two chapters give a detailed reconstruction of how this process reverberated in the communities of Carangas. The analysis presented in chapter six demonstrates that already under the land reform decrees preceding the mentioned Act, the communities secured their exemption from the decrees via a fiscal arrangement. Meanwhile, however, they lost their direct control over complementary valley lands. When disentailment was brought into operation, from the 1880s on, the announcement of a land inspection to implement the law fostered rebellious reactions against that intervention as well as a raise in inter-community conflicts over land. The threat posed by the altered legislation instigated the cooperation among community leaders to formulate a joint response, which involved the forging of strategic inter-ethnic alliances, erupting in a widespread rebellion during the 1899 federal war. Chapter seven continues with the post-1899 context, indicating how pressures on the land and the extractable resources it entailed increased, but the province’s commodity frontiers proved rather immobile. With regards to the land reform, pressures to introduce the new legislation got bogged down in endless delay, converting the province in one of the few completely hacienda-free regions of the Bolivian countryside. This went together with increasing internal conflict, communal mobilization, and strong but very ambiguous elite intervention. Special attention is given to this ambiguity, detecting a shared interest in the defence of communal lands that resulted from a gradual process of simultaneous usurpation and integration on part of the village elites. The chapter closes by explaining how the role of provincial elites nurtured a shift in the national discourse on the indigenous population, signalling the adoption of an integration policy. In short, the presented analysis tests the general hypothesis that processes of globalization nurture a diversity of transformation trajectories and that these diverse local processes “nourish” the global expansive-contractive course of capitalist developments by assessing the effects of a land-commodifying reform process in a region where most of the land was ánd remained subject to communal control. It demonstrates that “exemption” from the effects of such process is not merely a matter of isolation but is actively “extorted” in a dynamic renegotiation process. From a frontier perspective, the way in which a commodifying legislation was floored through communal action reflects the operation of feedback loops in the expansive course of world-systemic developments. The result is a thwarted incorporation process, visible in the constant (re)creation and assertion of alternative spaces for communal autonomy

Proceedings of the Caltech Conference on Very Large Scale Integration, held at the California Institute of Technology 22 - 24 January 1979 ; Organized by the Caltech Computer Science Department and the Caltech Industrial Associates Office

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