833 research outputs found

    DynAMO: Improving parallelism through dynamic placement of atomic memory operations

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    With increasing core counts in modern multi-core designs, the overhead of synchronization jeopardizes the scalability and efficiency of parallel applications. To mitigate these overheads, modern cache-coherent protocols offer support for Atomic Memory Operations (AMOs) that can be executed near-core (near) or remotely in the on-chip memory hierarchy (far). This paper evaluates current available static AMO execution policies implemented in multi-core Systems-on-Chip (SoC) designs, which select AMOs' execution placement (near or far) based on the cache block coherence state. We propose three static policies and show that the performance of static policies is application dependent. Moreover, we show that one of our proposed static policies outperforms currently available implementations. Furthermore, we propose DynAMO, a predictor that selects the best location to execute the AMOs. DynAMO identifies the different locality patterns to make informed decisions, improving AMO latency and increasing overall throughput. DynAMO outperforms the best-performing static policy and provides geometric mean speed-ups of 1.09× across all workloads and 1.31× on AMO-intensive applications with respect to executing all AMOs near.This research was supported by the Spanish Ministry of Science and Innovation (MCIN) through contracts [PID2019-107255GB-C21], [TED2021-132634A-I00], and [PID2019-105660RB-C21]; the Generalitat of Catalunya through contract [2021-SGR-00763]; the Government of Aragon [T5820R]; the Arm-BSC Center of Excellence, and the European Processor Initiative (EPI) which is part of the European Union’s Horizon 2020 research and innovation program under grant agreement No. 826647. V. Soria-Pardos has been supported through an FPU fellowship [FPU20-02132]; A. Armejach is a Serra Hunter Fellow and has been partially supported by the Grant [IJCI-2017-33945] funded by MCIN/AEI/10.13039/501100011033; M. Moreto through a Ramón y Cajal fellowship [RYC-2016-21104].Peer ReviewedPostprint (author's final draft

    Secure Cloud WLAN using Dynamic Placement with a Cloud Name Resolution Protocol

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    Cloud computing has displayed many intriguing possibilities since it was launched. Few of the cloud computing systems are centralized and might lead to bottlenecks under heavy traffic. This situation will influence security and leads to blockage of a greater part in the network especially when important routers and servers are not working. In the present years there has been a great development on Peer-to-Peer (P2P) cloud computing. In this work, we are providing a protocol to allow cloud servers easily interact and transport session state data between one another. The proposed methodology has been implemented using Visual Studio platform. The platform has been extensively tested and it has demonstrated promising results

    Cuestionario a Formadores, Profesionales Políticos! Administración Pública

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    .This article compiles the opinions of representatives from the professional and university sector, as we" as the Public Administration, on the current status of the profession: the most dynamic placement sectors, job characteristics and owlook.En el presente artículo se recogen las opiniones de representantes del sector profesional, universitario y de la Administración pública, sobre la situación actual de la profesión: sectores más dinámicos de inserción, características de los puestos de trabajo y perspectivas de futuro

    Dynamic Placement Analysis of Wind Power Generation Units in Distribution Power Systems

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    The placement problem of distributed generators (DGs) in distribution networks becomes much more complicated in the case of using the DGs with renewable energy resources. Due to several reasons such as, their intermittent output powers, the interactions between DGs and the rest of the distribution network, and considering other involved uncertainties are very vital. This paper develops a new approach for optimal placement of wind energy based DGs (WDGs) in which all of such influences are carefully handled. The proposed method considers the time variations of dynamic nodal demands, nodal voltage magnitudes, and wind speed in the WDG placement process simultaneously. Thereby, an accurate dynamic model of the active and reactive powers injected by the WDG to the system is employed in which the interactions between the WDG and the distribution network are well regarded. Finally, simulation results are given to show the capability of the proposed approach. As it is demonstrated in the numerical analysis of the radial 33-bus distribution test network, the proposed placement algorithm can efficiently determine the optimal bus for connecting the WDG and is suitable for real applications

    Dynamic, Latency-Optimal vNF Placement at the Network Edge

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    Future networks are expected to support low-latency, context-aware and user-specific services in a highly flexible and efficient manner. One approach to support emerging use cases such as, e.g., virtual reality and in-network image processing is to introduce virtualized network functions (vNF)s at the edge of the network, placed in close proximity to the end users to reduce end-to-end latency, time-to-response, and unnecessary utilisation in the core network. While placement of vNFs has been studied before, it has so far mostly focused on reducing the utilisation of server resources (i.e., minimising the number of servers required in the network to run a specific set of vNFs), and not taking network conditions into consideration such as, e.g., end-to-end latency, the constantly changing network dynamics, or user mobility patterns. In this paper, we formulate the Edge vNF placement problem to allocate vNFs to a distributed edge infrastructure, minimising end-to-end latency from all users to their associated vNFs. We present a way to dynamically re-schedule the optimal placement of vNFs based on temporal network-wide latency fluctuations using optimal stopping theory. We then evaluate our dynamic scheduler over a simulated nation-wide backbone network using real-world ISP latency characteristics. We show that our proposed dynamic placement scheduler minimises vNF migrations compared to other schedulers (e.g., periodic and always-on scheduling of a new placement), and offers Quality of Service guarantees by not exceeding a maximum number of latency violations that can be tolerated by certain applications

    Split and Migrate: Resource-Driven Placement and Discovery of Microservices at the Edge

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    Microservices architectures combine the use of fine-grained and independently-scalable services with lightweight communication protocols, such as REST calls over HTTP. Microservices bring flexibility to the development and deployment of application back-ends in the cloud. Applications such as collaborative editing tools require frequent interactions between the front-end running on users\u27 machines and a back-end formed of multiple microservices. User-perceived latencies depend on their connection to microservices, but also on the interaction patterns between these services and their databases. Placing services at the edge of the network, closer to the users, is necessary to reduce user-perceived latencies. It is however difficult to decide on the placement of complete stateful microservices at one specific core or edge location without trading between a latency reduction for some users and a latency increase for the others. We present how to dynamically deploy microservices on a combination of core and edge resources to systematically reduce user-perceived latencies. Our approach enables the split of stateful microservices, and the placement of the resulting splits on appropriate core and edge sites. Koala, a decentralized and resource-driven service discovery middleware, enables REST calls to reach and use the appropriate split, with only minimal changes to a legacy microservices application. Locality awareness using network coordinates further enables to automatically migrate services split and follow the location of the users. We confirm the effectiveness of our approach with a full prototype and an application to ShareLatex, a microservices-based collaborative editing application

    Situation awareness based automatic basestation detection and coverage reconfiguration in 3G systems

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