A Guide to Distributed Digital Preservation

This volume is devoted to the broad topic of distributed digital preservation, a still-emerging field of practice for the cultural memory arena. Replication and distribution hold out the promise of indefinite preservation of materials without degradation, but establishing effective organizational and technical processes to enable this form of digital preservation is daunting. Institutions need practical examples of how this task can be accomplished in manageable, low-cost ways."--P. [4] of cove

Apiary: Easy-to-use Desktop Application Fault Containment on Commodity Operating Systems

Desktop computers are often compromised by the interaction of untrusted data and buggy software. To address this problem, we present Apiary, a system that provides transparent application fault containment while retaining the ease of use of a traditional integrated desktop environment. Apiary accomplishes this with three key mechanisms. It isolates applications in containers that integrate in a controlled manner at the display and file system. It introduces ephemeral containers that are quickly instantiated for single application execution and then removed, to prevent any exploit that occurs from persisting and to protect user privacy. It introduces the virtual layered file system to make instantiating containers fast and space efficient, and to make managing many containers no more complex than having a single traditional desktop. We have implemented Apiary on Linux without any application or operating system kernel changes. Our results from running real applications, known exploits, and a 24-person user study show that Apiary has modest performance overhead, is effective in limiting the damage from real vulnerabilities to enable quick recovery, and is as easy to use as a traditional desktop while improving desktop computer security and privacy

Software Performance Analysis

The key to speeding up applications is often understanding where the elapsed time is spent, and why. This document reviews in depth the full array of performance analysis tools and techniques available on Linux for this task, from the traditional tools like gcov and gprof, to the more advanced tools still under development like oprofile and the Linux Trace Toolkit. The focus is more on the underlying data collection and processing algorithms, and their overhead and precision, than on the cosmetic details of the graphical user interface frontends

SEUSS: rapid serverless deployment using environment snapshots

Modern FaaS systems perform well in the case of repeat executions when function working sets stay small. However, these platforms are less effective when applied to more complex, large-scale and dynamic workloads. In this paper, we introduce SEUSS (serverless execution via unikernel snapshot stacks), a new system-level approach for rapidly deploying serverless functions. Through our approach, we demonstrate orders of magnitude improvements in function start times and cacheability, which improves common re-execution paths while also unlocking previously-unsupported large-scale bursty workloads.Published versio

Incrementando as redes centradas à informaçãopara uma internet das coisas baseada em nomes

The way we use the Internet has been evolving since its origins. Nowadays, users are more interested in accessing contents and services with high demands in terms of bandwidth, security and mobility. This evolution has triggered the emergence of novel networking architectures targeting current, as well as future, utilisation demands. Information-Centric Networking (ICN) is a prominent example of these novel architectures that moves away from the current host-centric communications and centres its networking functions around content. Parallel to this, new utilisation scenarios in which smart devices interact with one another, as well as with other networked elements, have emerged to constitute what we know as the Internet of Things (IoT). IoT is expected to have a significant impact on both the economy and society. However, fostering the widespread adoption of IoT requires many challenges to be overcome. Despite recent developments, several issues concerning the deployment of IPbased IoT solutions on a large scale are still open. The fact that IoT is focused on data and information rather than on point-topoint communications suggests the adoption of solutions relying on ICN architectures. In this context, this work explores the ground concepts of ICN to develop a comprehensive vision of the principal requirements that should be met by an IoT-oriented ICN architecture. This vision is complemented with solutions to fundamental issues for the adoption of an ICN-based IoT. First, to ensure the freshness of the information while retaining the advantages of ICN’s in-network caching mechanisms. Second, to enable discovery functionalities in both local and large-scale domains. The proposed mechanisms are evaluated through both simulation and prototyping approaches, with results showcasing the feasibility of their adoption. Moreover, the outcomes of this work contribute to the development of new compelling concepts towards a full-fledged Named Network of Things.A forma como usamos a Internet tem vindo a evoluir desde a sua criação. Atualmente, os utilizadores estão mais interessados em aceder a conteúdos e serviços, com elevados requisitos em termos de largura de banda, segurança e mobilidade. Esta evolução desencadeou o desenvolvimento de novas arquiteturas de rede, visando os atuais, bem como os futuros, requisitos de utilização. As Redes Centradas à Informação (Information-Centric Networking - ICN) são um exemplo proeminente destas novas arquiteturas que, em vez de seguirem um modelo de comunicação centrado nos dispositivos terminais, centram as suas funções de rede em torno do próprio conteúdo. Paralelamente, novos cenários de utilização onde dispositivos inteligentes interagem entre si, e com outros elementos de rede, têm vindo a aparecer e constituem o que hoje conhecemos como a Internet das Coisas (Internet of Things - IoT ). É esperado que a IoT tenha um impacto significativo na economia e na sociedade. No entanto, promover a adoção em massa da IoT ainda requer que muitos desafios sejam superados. Apesar dos desenvolvimentos recentes, vários problemas relacionados com a adoção em larga escala de soluções de IoT baseadas no protocolo IP estão em aberto. O facto da IoT estar focada em dados e informação, em vez de comunicações ponto-a-ponto, sugere a adoção de soluções baseadas em arquiteturas ICN. Neste sentido, este trabalho explora os conceitos base destas soluções para desenvolver uma visão completa dos principais requisitos que devem ser satisfeitos por uma solução IoT baseada na arquitetura de rede ICN. Esta visão é complementada com soluções para problemas cruciais para a adoção de uma IoT baseada em ICN. Em primeiro lugar, assegurar que a informação seja atualizada e, ao mesmo tempo, manter as vantagens do armazenamento intrínseco em elementos de rede das arquiteturas ICN. Em segundo lugar, permitir as funcionalidades de descoberta não só em domínios locais, mas também em domínios de larga-escala. Os mecanismos propostos são avaliados através de simulações e prototipagem, com os resultados a demonstrarem a viabilidade da sua adoção. Para além disso, os resultados deste trabalho contribuem para o desenvolvimento de conceitos sólidos em direção a uma verdadeira Internet das Coisas baseada em Nomes.Programa Doutoral em Telecomunicaçõe

Evaluation of Storage Systems for Big Data Analytics

abstract: Recent trends in big data storage systems show a shift from disk centric models to memory centric models. The primary challenges faced by these systems are speed, scalability, and fault tolerance. It is interesting to investigate the performance of these two models with respect to some big data applications. This thesis studies the performance of Ceph (a disk centric model) and Alluxio (a memory centric model) and evaluates whether a hybrid model provides any performance benefits with respect to big data applications. To this end, an application TechTalk is created that uses Ceph to store data and Alluxio to perform data analytics. The functionalities of the application include offline lecture storage, live recording of classes, content analysis and reference generation. The knowledge base of videos is constructed by analyzing the offline data using machine learning techniques. This training dataset provides knowledge to construct the index of an online stream. The indexed metadata enables the students to search, view and access the relevant content. The performance of the application is benchmarked in different use cases to demonstrate the benefits of the hybrid model.Dissertation/ThesisMasters Thesis Computer Science 201

On-line data archives

©2001 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Digital libraries and other large archives of electronically retrievable and manipulable material are becoming widespread in both commercial and scientific arenas. Advances in networking technologies have led to a greater proliferation of wide-area distributed data warehousing with associated data management challenges. We review tools and technologies for supporting distributed on-line data archives and explain our key concept of active data archives, in which data can be, processed on-demand before delivery. We are developing wide-area data warehousing software infrastructure for geographically distributed archives of large scientific data sets, such as satellite image data, that are stored hierarchically on disk arrays and tape silos and are accessed by a variety of scientific and decision support applications. Interoperability is a major issue for distributed data archives and requires standards for server interfaces and metadata. We review present activities and our contributions in developing such standards for different application areas.K. Hawick, P. Coddington, H. James, C. Patte