MultiLibOS: an OS architecture for cloud computing

Cloud computing is resulting in fundamental changes to computing infrastructure, yet these changes have not resulted in corresponding changes to operating systems. In this paper we discuss some key changes we see in the computing infrastructure and applications of IaaS systems. We argue that these changes enable and demand a very different model of operating system. We then describe the MulitLibOS architecture we are exploring and how it helps exploit the scale and elasticity of integrated systems while still allowing for legacy software run on traditional OSes

Total order broadcast for fault tolerant exascale systems

In the process of designing a new fault tolerant run-time for future exascale systems, we discovered that a total order broadcast would be necessary. That is, nodes of a supercomputer should be able to broadcast messages to other nodes even in the face of failures. All messages should be seen in the same order at all nodes. While this is a well studied problem in distributed systems, few researchers have looked at how to perform total order broadcasts at large scales for data availability. Our experience implementing a published total order broadcast algorithm showed poor scalability at tens of nodes. In this paper we present a novel algorithm for total order broadcast which scales logarithmically in the number of processes and is not delayed by most process failures. While we are motivated by the needs of our run-time we believe this primitive is of general applicability. Total order broadcasts are used often in datacenter environments and as HPC developers begins to address fault tolerance at the application level we believe they will need similar primitives

EbbRT: Elastic Building Block Runtime - case studies

We present a new systems runtime, EbbRT, for cloud hosted applications. EbbRT takes a different approach to the role operating systems play in cloud computing. It supports stitching application functionality across nodes running commodity OSs and nodes running specialized application specific software that only execute what is necessary to accelerate core functions of the application. In doing so, it allows tradeoffs between efficiency, developer productivity, and exploitation of elasticity and scale. EbbRT, as a software model, is a framework for constructing applications as collections of standard application software and Elastic Building Blocks (Ebbs). Elastic Building Blocks are components that encapsulate runtime software objects and are implemented to exploit the raw access, scale and elasticity of IaaS resources to accelerate critical application functionality. This paper presents the EbbRT architecture, our prototype and experimental evaluation of the prototype under three different application scenarios

Bioelectrical dynamics are required for normal development of the sea urchin embryo

Bioelectricity refers to differential membrane voltage and cytoplasmic ion concentrations in tissues or cells which persist over long periods of time. Differences in these steady-state ionic conditions are responsible for large-scale axial patterning and morphogenesis in developing embryos. The sea urchin embryo is an excellent model organism for studying embryonic development, yet a comprehensive study of bioelectricity in sea urchin development has not been reported. Differential ion channel activity is a primary means by which bioelectricity is controlled; thus, we hypothesized that disrupting ion channel activity would reveal the requirements for bioelectricity in the sea urchin embryo. We performed a screen of ion channel inhibitors and discovered that their activities are required for many processes in sea urchin development. We chose two interesting phenotypes to investigate further. First, we demonstrate that H+/K+ ATPase (HKA) activity is required for biomineralization of the sea urchin larval skeleton. We determined that embryos raised with HKA inhibitors initially exhibit voltage and pH changes, then revert to normal voltage and pH during biomineralization via compensatory changes in sodium and chloride ions; it is likely that these compensatory changes lead to defects in transport of carbonate ions, that in turn, inhibit biomineralization of the calcium carbonate skeleton. We hypothesize that similar mechanisms are at play in human patients on long-term HKA inhibitors to treat acid reflux, in whom biomineralization is also decreased. Next, we demonstrate that V-type H+ ATPase (VHA) activity is required for specification of the dorsal-ventral (DV) axis, for the normal inactivation of p38 MAPK in the presumptive dorsal region, and for the subsequent asymmetric onset of expression of the TGFβ family member Nodal, that locally specifies the ventral territory. Embryos treated with VHA inhibitors exhibit global p38 MAPK activity and Nodal expression, and are ventralized. We describe previously unknown gradients of voltage and pH across the DV axis, the sharpness of which requires VHA activity. We propose that the voltage and pH gradients encode spatial information which confers asymmetry on p38 MAPK activity. Overall, we demonstrate that bioelectrical changes are essential for development of the sea urchin embryo, specifically via roles in biomineralization and DV axis specification.2019-01-2

Classifying Derived Voltage Graphs

Gross and Tucker’s voltage graph construction assigns group elements as weights to the edges of an oriented graph. This construction provides a blueprint for inducing graph covers. Thomas Zaslavsky studies the criteria for balance in voltage graphs. This project primarily examines the relationship between the group structure of the set of all possible assignments of a group to a graph, including the balanced subgroup, and the isomorphism classes of covering graphs. We examine connectedness, planarity, and chromatic number in the derived graph. Lastly we explain the future research possibilities involving the fundamental group

EbbRT: a framework for building per-application library operating systems

Efficient use of high speed hardware requires operating system components be customized to the application work- load. Our general purpose operating systems are ill-suited for this task. We present EbbRT, a framework for constructing per-application library operating systems for cloud applications. The primary objective of EbbRT is to enable high-performance in a tractable and maintainable fashion. This paper describes the design and implementation of EbbRT, and evaluates its ability to improve the performance of common cloud applications. The evaluation of the EbbRT prototype demonstrates memcached, run within a VM, can outperform memcached run on an unvirtualized Linux. The prototype evaluation also demonstrates an 14% performance improvement of a V8 JavaScript engine benchmark, and a node.js webserver that achieves a 50% reduction in 99th percentile latency compared to it run on Linux

EbbRT: Elastic Building Block Runtime - overview

EbbRT provides a lightweight runtime that enables the construction of reusable, low-level system software which can integrate with existing, general purpose systems. It achieves this by providing a library that can be linked into a process on an existing OS, and as a small library OS that can be booted directly on an IaaS node

EbbRT: a customizable operating system for cloud applications

Efficient use of hardware requires operating system components be customized to the application workload. Our general purpose operating systems are ill-suited for this task. We present Genesis, a new operating system that enables per-application customizations for cloud applications. Genesis achieves this through a novel heterogeneous distributed structure, a partitioned object model, and an event-driven execution environment. This paper describes the design and prototype implementation of Genesis, and evaluates its ability to improve the performance of common cloud applications. The evaluation of the Genesis prototype demonstrates memcached, run within a VM, can outperform memcached run on an unvirtualized Linux. The prototype evaluation also demonstrates an 14% performance improvement of a V8 JavaScript engine benchmark, and a node.js webserver that achieves a 50% reduction in 99th percentile latency compared to it run on Linux

Soccer, science, and sorcery: causation and African football

'Dieser Beitrag behandelt zwei Arten politischer Kausalität: Zum einen die zeitgenössische wissenschaftliche Erklärungsweise, die in den Sozialwissenschaften zumeist unhinterfragt angewandt und als universell und in allen Kontexten gültig angenommen wird, zum anderen - weil er auf afrikanisches Datenmaterial Bezug nimmt und die empirischen Beispiele aus dem Bereich des Fußballs stammen - eine Erklärungsform, die auf aktiver Manipulation von übernatürlichen Kräften beruht und in Afrika meist mit 'Hexerei' oder 'Magie' bezeichnet wird. Der Aufsatz untersucht zunächst - anhand von Beispielen vor allem der Weltmeisterschaft 2002 -, wie diese beiden unterschiedlichen Erklärungsmuster im afrikanischen Fußball generell deutlich werden. Anschließend analysiert er detailliert ein Spiel zwischen den Nationalmannschaften von Uganda und Rwanda im Jahr 2003, um das Wechselspiel von Wissenschaft und 'Hexerei' aus einem 'kontrollierteren' Blickwinkel heraus zu zeigen.' (Autorenreferat)'This article treats two modes of political causation. First, the contemporary scientific mode that most social sciences simply take for granted and assume, quite unthinkingly, to be universally applicable and valid in all circumstances. Second, because the discussion uses African materials and empirical examples drawn from the realm of football, the article also explores a mode of causation based on the active manipulation of supernatural forces that in much of Africa is usually called witchcraft or sorcery. The essay begins with a general examination of how these two modes of understanding causation play themselves out in African football with examples drawn largely from the 2002 World Cup. It then presents a more focused analysis of one match between the national sides of Uganda and Rwanda that occurred in 2003 to demonstrate the interplay of science and sorcery in a more 'controlled' manner.' (author's abstract)