38 research outputs found

    Virtualization for a Network Processor Runtime System

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    The continuing ossification of the Internet is slowing the pace of network innovation. Network diversification presents one solution to this problem, by virtualizing the network at multiple layers. Diversified networks consist of a shared physical substrate, virtual routers (metarouters), and virtual links (metalinks). Virtualizing routers enables smooth and incremental upgrades to new network services. Our current priority for a diversified router prototype is to enable reserved slices of the network for researchers to perform repeatable, high-speed network experiments. General-purpose processors have well established techniques for virtualization, but do not scale efficiently to multi-gigabit speeds. To achieve these speeds, we employ network processors (NPs), typically consisting of multicore, multi-threaded processors with asymmetric, heterogeneous memories. The complexity and lack of hardware thread isolation in NP’s, combined with a lack of simple programming models, creates numerous challenges for effective sharing between metarouters. In this paper, we detail strategies for enabling NP virtualization at the link, memory, and processor levels, to better enable a research infrastructure for network innovation

    Decoupling Information and Connectivity in Information-Centric Networking

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    This paper introduces and demonstrates the concept of Information-Centric Transport as a mechanism for cleanly decoupling the information plane from the connectivity plane in Information-Centric Networking (ICN) architectures, such as NDN and CICN. These are coupled in today\u27s incarnations of NDN and CICN through the use of forwarding strategy, which is the architectural component for deciding how to forward packets in the presence of either multiple next-hop options or dynamic feedback. As presently designed, forwarding strategy is not sustainable: application developers can only confidently specify strategy if they understand connectivity details, while network node operators can only confidently assign strategies if they understand application expectations. We show how Information-Centric Transport allows applications to operate on the information plane, concerned only with the namespace and identities relevant to the application, leaving network node operators free to implement ICT services in whatever way makes sense for the connectivity that they manage. To illustrate ICT, we introduce sync*, a synchronization service, and show how a) its use enables applications to operate well regardless of connectivity details and b) its implementation can be completely managed by network operators with no knowledge of application details

    Supercharged PlanetLab Platform Architecture

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    This report describes the Supercharged Planetlab Platform (SPP), a system designed as a prototype of an internet-scale overlay hosting platform. Overlay networks have become an important vehicle for delivering Internet applications. Overlay network nodes are typically implemented using general purpose servers or clusters. The SPP offers a more integrated architecture, combining general-purpose servers with high performance Network Processor (NP) subsystems. SPP nodes have recently been deployed as part of the Global Environment for Network Innovation (GENI) and are available for use by research users

    Concert recording 2018-04-19b

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    [Track 1]. Sonatina meridional / Manuel Ponce -- [Track 2]. Etude no. 6 / Hector Villa-Lobos -- [Track 3]. Milonga / Jorge Cardoso -- [Track 4]. Straight no chaser / T. Monk -- [Track 5]. A child is born / T. Monk -- [Track 6]. Autumn leaves / J. Kosma -- [Track 7]. Body and soul / J. Green -- [Track 8]. All the things you are / J. Kern -- [Track 9]. 4 on 6 / Wes Montgomery -- [Track 10]. Bright size life / P. Metheny -- [Track 11]. Dueling banjos / Arthur Smith -- [Track 12]. Elenor Rigby / Lennon and McCartney -- [Track 13]. Alone / Bryce Holcomb -- [Track 14]. All around me / Flyleaf -- Vital transformation / Mahavisunu Orchestra

    Concert recording 2017-12-03b

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    [Track 1]. Boogie wonderland / Earth Wind and Fire -- [Track 2]. Think / Aretha Franklin -- [Track 3]. Please please please / James Brown -- [Track 4]. Your precious love / Tammi Terrell -- [Track 5]. September / Earth Wind and Fire -- [Track 6]. Window seat / Erykah Badu -- [Track 7]. Going down / Norman Whitfield -- [Track 8]. Uptown funk / Mark Ronson, Bruno Mars, Philip Lawrence, Jeff Bhasker, Devon Gallaspy

    Concert recording 2018-04-14

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    [Track 1]. Lonely avenue / Ray Charles -- [Track 2]. Boogie wonderland / Earth Wind and Fire -- [Track 3]. Think / Aretha Franklin -- [Track 4]. Please please please / James Brown -- [Track 5]. Your precious love / Tammi Terrell -- [Track 6]. September / Earth Wind and Fire -- [Track 7]. Baby brown eyes / Alisha Jones -- [Track 8]. Window seat / Erykah Badu -- [Track 9]. Smooth criminal / Michael Jackson -- [Track 10]. Going down / Norma Whitfield -- [Track 11]. Uptown funk / Mark Ronson Bruno Mars Philip Lawrence Jeff Bhasker Devon Gallaspy Nicholas Williams -- [Track 12]. Curley green hair / Jacob Skinner -- [Track 13]. You think of her / Shelby Sprott -- [Track 14]. Coffee song / Jordan Strickland Walter Ferguson -- [Track 15]. Leave a trace / Churches -- [Track 16]. Real one / Alisha Jones -- [Track 17]. Reality / Jordan Strickland -- [Track 18]. Still into you / Paramore -- [Track 19]. Alive / Carlie Spiers

    Concert recording 2017-12-05a

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    [Track 1]. Lou Brouwer medley / Brouwer -- [Track 2]. One summer\u27s day / Daniel Asbun -- [Track 3]. What a friend we have in Jesus / Brad Paisley -- [Track 4]. Unity village / Pat Metheny -- [Track 5] Truth? / Asher Perkins -- [Track 6]. Invention no. 13 / J.S. Bach -- [Track 7]. Black Orpheus / Stan Getz arranged Luiz Bonfa -- [Track 8]. Five Hawaiian minutes / Shiro Mori -- [Track 9]. Birks works / Dizzy Gillespie -- [Track 10]. Perhaps / Charlie Parker -- [Track 11]. The river / King Gizzard and the Lizard Wizard -- [Track 12]. Minor swing / Django Reinhardt and Stephan Grappelli -- [Track 13]. Why break mine / Legally blind -- [Track 14]. Monochrome / Carlie Spiers -- [Track 15]. Stuck in voodoo / Dawson Scantling -- [Track 16]. I\u27m saved / Shelby Sprott -- [Track 17]. Newborn / Muse -- [Track 18]. Blueberry brain / Elephantom

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Supercharging PlanetLab – A High Performance, Multi-Application, Overlay Network Platform

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    In recent years, overlay networks have become an important vehicle for delivering Internet applications. Overlay network nodes are typically implemented using general purpose servers or clusters. We investigate the performance benefits of more integrated architectures, combining general-purpose servers with high performance Network Processor (NP) subsystems. We focus on PlanetLab as our experimental context and report on the design and evaluation of an experimental PlanetLab platform capable of much higher levels of performance than typical system configurations. To make it easier for users to port applications, the system supports a fast path/slow path application structure that facilitates the mapping of the most performance-critical parts of an application onto an NP subsystem, while allowing the more complex control and exception-handling to be implemented within the programmer-friendly environment provided by conventional servers. We report on implementations of two sample applications, an IPv4 router, and a forwarding application for the Internet Indirection Infrastructure. We demonstrate an 80 Ă— improvement in packet processing rates and comparable reductions in latency. This work supported in part by NSF (grants 0520778 and 0626661)
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