317 research outputs found

    Hierarchical Service Placement for Demanding Applications

    Get PDF
    The increasing scale of cloud environments requires more scalable orchestration systems for determining which physical resources are responsible for processing service requests. A centralised service placement lacks scalability while a fully decentralised approach only has a limited view of the system. For these reasons, this paper investigates a hierarchical approach for service placement in a distributed environment, which increases scalability while maintains high service placement quality. First, we design a polynomial optimisation algorithm to place services in cloud data centers based on our novel utility function. Then, we describe a hierarchical model with the need to only know a small subset of the data required by the global optimisation formulation. Simulations show that our approach is scalable and performs well, close to the centralised model

    On the Feasibility of Using Current Data Centre Infrastructure for Latency-sensitive Applications

    Get PDF
    IEEE It has been claimed that the deployment of fog and edge computing infrastructure is a necessity to make high-performance cloud-based applications a possibility. However, there are a large number of middle-ground latency-sensitive applications such as online gaming, interactive photo editing and multimedia conferencing that require servers deployed closer to users than in globally centralised clouds but do not necessarily need the extreme low-latency provided by a new infrastructure of micro data centres located at the network edge, e.g. in base stations and ISP Points of Presence. In this paper we analyse a snapshot of today & #x0027;s data centres and the distribution of users around the globe and conclude that existing infrastructure provides a sufficiently distributed platform for middle-ground applications requiring a response time of 20200  ms20-200\;ms . However, while placement and selection of edge servers for extreme low-latency applications is a relatively straightforward matter of choosing the closest, providing a high quality of experience for middle-ground latency applications that use the more widespread distribution of today & #x0027;s data centres, as we advocate in this paper, raises new management challenges to develop algorithms for optimising the placement of and the per-request selection between replicated service instances

    UCIP: User controlled internet protocol

    Get PDF
    Internet protocols have developed significantly over the last 50 years but have reached a point where the further improvements in performance, resilience, security and privacy cannot be achieved by simple incremental changes. This paper proposes a new IP protocol that puts the user's end host at the centre of major algorithmic decisions. It consist of three new mechanisms: a private source routing establishment protocol that allows inter-domain traffic routes to be decided by the user and kept private from the providers whilst allowing for anonymous connections where two node can communicate without knowing the identity/address of the other end point; a mechanism to control reception of packets that mitigates denial-of-service attacks and a new directory system that puts the end user at the core of the decisions enabling anycast and mobility with a pub-sub mechanism with fine grain capabilities for describe resources. These changes allow end nodes to have a much tighter control of how they send and receive their traffic and provide a paradigm shift for the Internet ecosystem

    Resource Provisioning and Allocation in Function-as-a-Service Edge-Clouds

    Get PDF
    Edge computing has emerged as a new paradigm to bring cloud applications closer to users for increased performance. Unlike back-end cloud systems which consolidate their resources in a centralized data center location with virtually unlimited capacity, edge-clouds comprise distributed resources at various computation spots, each with very limited capacity. In this paper, we consider Function-as-a-Service (FaaS) edge-clouds where application providers deploy their latency-critical functions that process user requests with strict response time deadlines. In this setting, we investigate the problem of resource provisioning and allocation. After formulating the optimal solution, we propose resource allocation and provisioning algorithms across the spectrum of fully-centralized to fully-decentralized. We evaluate the performance of these algorithms in terms of their ability to utilize CPU resources and meet request deadlines under various system parameters. Our results indicate that practical decentralized strategies, which require no coordination among computation spots, achieve performance that is close to the optimal fully-centralized strategy with coordination overheads

    R2L: Routing With Reinforcement Learning

    Get PDF
    In a packet network, the routes taken by traffic can be determined according to predefined objectives. Assuming that the network conditions remain static and the defined objectives do not change, mathematical tools such as linear programming could be used to solve this routing problem. However, networks can be dynamic or the routing requirements may change. In that context, Reinforcement Learning (RL), which can learn to adapt in dynamic conditions and offers flexibility of behavior through the reward function, presents as a suitable tool to find good routing strategies. In this work, we train an RL agent, which we call R2L, to address the routing problem. The policy function used in R2L is a neural network and we use an evolution strategy algorithm to determine its weights and biases. We tested R2L in two different scenarios: static and dynamic networks conditions. In the first, we used a 16-node network and experimented with different reward functions, observing that R2L was able to adapt its routing behavior accordingly. Finally, in the second experiment, we used a 5-node network topology where a given link's transmission rate changed during the simulation. In this scenario, we observed that R2L was able to deliver a competitive performance, compared to heuristic benchmarks, with changing network conditions

    On Uncoordinated Service Placement in Edge-Clouds

    Get PDF
    Edge computing has emerged as a new paradigm to bring cloud applications closer to users for increased performance. ISPs have the opportunity to deploy private edge-clouds in their infrastructure to generate additional revenue by providing ultra-low latency applications to local users. We envision a rapid increase in the number of such applications for “edge” networks in the near future with virtual/augmented reality (VR/AR), networked gaming, wearable cognitive assistance, autonomous driving and IoT analytics having already been proposed for edge- clouds instead of the central clouds to improve performance. This raises new challenges as the complexity of the resource allocation problem for multiple services with latency deadlines (i.e., which service to place at which node of the edge-cloud in order to satisfy the latency constraints) becomes significant. In this paper, we propose a set of practical, uncoordinated strategies for service placement in edge-clouds. Through extensive simulations using both synthetic and real-world trace data, we demonstrate that uncoordinated strategies can perform comparatively well with the optimal placement solution, which satisfies the maximum amount of user requests

    Quality of experience for 3-d immersive media streaming

    Get PDF
    Recent advances in media capture and processing technologies have enabled new forms of true 3-D media content that increase the degree of user immersion. The demand for more engaging forms of entertainment means that content distributors and broadcasters need to fine-tune their delivery mechanisms over the Internet as well as develop new models for quantifying and predicting user experience of these new forms of content. In the work described in this paper, we undertake one of the first studies into the quality of experience (QoE) of real-time 3-D media content streamed to virtual reality (VR) headsets for entertainment purposes, in the context of game spectating. Our focus is on tele-immersive media that embed real users within virtual environments of interactive games. A key feature of engaging and realistic experiences in full 3-D media environments, is allowing users unrestricted viewpoints. However, this comes at the cost of increased network bandwidth and the need of limiting network effects in order to transmit a realistic, real-time representation of the participants. The visual quality of 3-D media is affected by geometry and texture parameters while the temporal aspects of smooth movement and synchronization are affected by lag introduced by network transmission effects. In this paper, we investigate varying network conditions for a set of tele-immersive media sessions produced in a range of visual quality levels. Further, we investigate user navigation issues that inhibit free viewpoint VR spectating of live 3-D media. After reporting on a study with multiple users we analyze the results and assess the overall QoE with respect to a range of visual quality and latency parameters. We propose a neural network QoE prediction model for 3-D media, constructed from a combination of visual and network parameters

    A System Architecture for Live Immersive 3D-Media Transcoding over 5G Networks

    Get PDF
    The upcoming 5G networks, among other technological advances, bring Network Function Virtualization (NFV) capabilities enabling deployment of application service intelligence on their Next Generation Core (NGC). Application specific logic is packaged into Virtual Network Functions (VNFs) so that their instantiation and deployment can be done at any node of the NGC, with their management and orchestration being maintained by the 5G infrastructure. While the number of instances of each VNF and their placement inside the NGC network are managed by the 5G infrastructure, such management cannot be optimal without application context. In this paper, we propose a 5G oriented system architecture for a next generation augmented virtuality tele-immersive two-player video game application. In the presented video game, the players compete in a capture the flag race in an innovative game movement control setting which uses motion capture technology to allow the players to interact with the game via their body posture and hand gestures. On the top of this, real-time 3D-Reconstruction technology is utilized to create 3D avatars of the players and embed them inside the game environment. Apart from the players, the application also supports real-time spectating of the game action by a considerable amount of spectators that join the live game via client software designed for desktop PCs, smartphones and tablets, connected through mobile or fixed access networks. To distribute the 3D traffic to such a number of consumers that have different device capabilities and are located at varying geographical locations while offering the highest possible Quality of Experience (QoE), is a challenging task. One of the contemporary ways to address this problem is via adaptive streaming. To realize this concept, realtime 3D-Media Transcoders need to be employed. The proposed system architecture considers packaging the aforementioned 3D-Media Transcoders as VNFs that can be deployed on 5G infrastructure. In the paper, it is shown that such an architecture can decrease costs for a given level of offered QoE, with evident benefits for the game service's shareholders. While the application type presented in this paper is fixed, the proposed system architecture can be adopted by other applications of similar context with similar benefits gained from the flexible deployment of virtualised applications in 5G networks

    Ventricular noncompaction in a female patient with nephropathic cystinosis: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>We report an unusual and interesting case of a 24-year-old woman with nephropathic cystinosis in association with concomitant isolated noncompaction of the left ventricle. Left ventricular noncompaction usually presents with reduced exercise tolerance as a consequence of ventricular dysfunction, the result of embolus or with palpitations and syncope due to arrhythmia. There is no specific treatment directed at isolated noncompaction. Treatment is focused on the cause of presentation, with medication aimed at improving ventricular dysfunction, as well as treating and preventing thrombosis and arrhythmia.</p> <p>Case presentation</p> <p>Our patient presented with an episode of decompensated heart failure. Trans-thoracic echocardiography demonstrated excessive trabeculation with inter-trabecular recesses in the left ventricle typical of noncompaction of the left ventricle. The patient's admission was complicated by a cardiac arrest precipitated by ventricular tachycardia for which she subsequently underwent implantation of an automatic implantable cardioverter defibrillator.</p> <p>Conclusion</p> <p>This is, as far as we know, the first case report of the co-existence of nephropathic cystinosis and isolated noncompaction of the left ventricle. It highlights the importance of being vigilant to the diagnosis of left ventricular noncompaction.</p
    corecore