1,720,955 research outputs found
Fault injections on mission-critical computer systems
Get PDFThis thesis presents two unique sets of fault injections on mission-critical computer systems with the goal of (1) understanding the impact of faults, errors and failures, and (2) evaluating fault-tolerance and resilience of the targeted systems in the presence of failures.
Our first fault injection campaign studies the effects of failures on high-performance computing (HPC) systems. We target the Cray XE Blue Waters JYC testbed at the National Center for Supercomputing Applications, with the goal of improving the understanding of failure causes and propagation observed in the field failure data analysis of Blue Waters. We use data collected from system logs and network performance counters to (1) characterize fault-error-failure sequences and recovery mechanisms in Gemini interconnection networks and in Cray compute elements, (2) understand the impact of failures on the system and user applications at different scales, and (3) identify and recreate fault scenarios that induce unrecoverable failures, to create new tests for system and application design. We utilize HPCArrow, a newly developed software-implemented fault injection tool with the ability to disable and restore user-specified network links, directional connections, compute nodes and blades. We observe failures manifesting in the form of applications not making forward progress and network quiescence operations causing extended system recovery times.
Our second fault injection campaign studies the effects of faults, attacks and failures on a smart power grid utilizing software-defined networking (SDN) to orchestrate its data acquisition network. We evaluate our fault models on a smart power grid simulation running Raincoat, an SDN application that reroutes and spoofs network traffic to thwart attackers. Additionally, we propose an application- and data plane-based solution to pro-actively monitor system state and enforce user defined policies. We show that under certain faults, (1) applications orchestrating the network become ineffective, and (2) periodically monitoring the state of the network can identify faults or attacks before they manifest as failures. The results obtained from this work can aid in enhancing the resiliency of future SDN applications.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2020-08-01The student, Lavin Devnani, accepted the attached license on 2018-07-18 at 13:24.The student, Lavin Devnani, submitted this Thesis for approval on 2018-07-18 at 13:28.This Thesis was approved for publication on 2018-07-18 at 14:19.DSpace SAF Submission Ingestion Package generated from Vireo submission #12626 on 2018-09-27 at 11:33:12Made available in DSpace on 2018-09-27T16:45:31Z (GMT). No. of bitstreams: 2
DEVNANI-THESIS-2018.pdf: 4875875 bytes, checksum: 61c85eb93aa91fdef4b6320cdf64ac49 (MD5)
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Previous issue date: 2018-07-18Embargo set by: Seth Robbins for item 107856
Lift date: 2020-09-27T16:45:39Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 107856
Lift date: 2020-09-27T16:47:41Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 107856 on 2020-09-28T09:15:13Z
INTEL VT-X ON QEMU
No full textOver the past decade, virtualization technologies have evolved from research and educational tools to scalable IT solutions deployed across
servers worldwide.
However, current reliability and security development tools such as
QEMU lack support for analyzing hardware extensions provided by Intel's
virtualization technology (VT-x). This project aims to extend QEMU
support for hardware assisted virtualization by adding virtualization related control structures to QEMU's emulated processor, supporting
translation of the
Intel VT-x instruction set and developing APIs for use with future projects.
Having Intel VT-x on QEMU contributes to the overall goal of
performing dynamic analysis of HAV, and supports future projects such
as Taint Analysis, Symbolic Execution and prototyping new hypervisors/ hypervisor monitoring tools.U of I OnlySenior research thesis not recommended for open acces
INTEL VT-X ON QEMU
No full textOver the past decade, virtualization technologies have evolved from research and educational tools to scalable IT solutions deployed across
servers worldwide.
However, current reliability and security development tools such as
QEMU lack support for analyzing hardware extensions provided by Intel's
virtualization technology (VT-x). This project aims to extend QEMU
support for hardware assisted virtualization by adding virtualization related control structures to QEMU's emulated processor, supporting
translation of the
Intel VT-x instruction set and developing APIs for use with future projects.
Having Intel VT-x on QEMU contributes to the overall goal of
performing dynamic analysis of HAV, and supports future projects such
as Taint Analysis, Symbolic Execution and prototyping new hypervisors/ hypervisor monitoring tools.Submitted by Janice Progen ([email protected]) on 2016-06-29T19:12:11Z
No. of bitstreams: 1
ECE499-Sp2016-devnani.pdf: 312751 bytes, checksum: 9bb25e5cd22dff4c4def77a892a0f1b0 (MD5)Approved for entry into archive by James Hutchinson ([email protected]) on 2016-06-29T19:27:29Z (GMT) No. of bitstreams: 1
ECE499-Sp2016-devnani.pdf: 312751 bytes, checksum: 9bb25e5cd22dff4c4def77a892a0f1b0 (MD5)Made available in DSpace on 2016-06-29T19:27:29Z (GMT). No. of bitstreams: 1
ECE499-Sp2016-devnani.pdf: 312751 bytes, checksum: 9bb25e5cd22dff4c4def77a892a0f1b0 (MD5)
Previous issue date: 2016-05Embargo set by: James Hutchinson for item 92707
Lift date: 10000-01-01
Reason: Senior research thesis not recommended for open accessSenior research thesis not recommended for open accessU of I Onl
Fault injections on mission-critical computer systems
No full textThis thesis presents two unique sets of fault injections on mission-critical computer systems with the goal of (1) understanding the impact of faults, errors and failures, and (2) evaluating fault-tolerance and resilience of the targeted systems in the presence of failures.
Our first fault injection campaign studies the effects of failures on high-performance computing (HPC) systems. We target the Cray XE Blue Waters JYC testbed at the National Center for Supercomputing Applications, with the goal of improving the understanding of failure causes and propagation observed in the field failure data analysis of Blue Waters. We use data collected from system logs and network performance counters to (1) characterize fault-error-failure sequences and recovery mechanisms in Gemini interconnection networks and in Cray compute elements, (2) understand the impact of failures on the system and user applications at different scales, and (3) identify and recreate fault scenarios that induce unrecoverable failures, to create new tests for system and application design. We utilize HPCArrow, a newly developed software-implemented fault injection tool with the ability to disable and restore user-specified network links, directional connections, compute nodes and blades. We observe failures manifesting in the form of applications not making forward progress and network quiescence operations causing extended system recovery times.
Our second fault injection campaign studies the effects of faults, attacks and failures on a smart power grid utilizing software-defined networking (SDN) to orchestrate its data acquisition network. We evaluate our fault models on a smart power grid simulation running Raincoat, an SDN application that reroutes and spoofs network traffic to thwart attackers. Additionally, we propose an application- and data plane-based solution to pro-actively monitor system state and enforce user defined policies. We show that under certain faults, (1) applications orchestrating the network become ineffective, and (2) periodically monitoring the state of the network can identify faults or attacks before they manifest as failures. The results obtained from this work can aid in enhancing the resiliency of future SDN applications.LimitedAuthor requested closed access (OA after 2yrs) in Vireo ETD syste
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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