FRuIT: The Federated RaspberryPi Micro-Infrastructure Testbed

无处不在的低成本、低功耗计算设备的引入，例如在物联网（IoT）中，正在从根本上改变计算领域。虽然我们已经看到了特殊用途物联网设备提供的好处，但只有当我们可以将大量分布式设备重新用作更大的联邦服务的一部分时，才能实现真正的功能。这在FRUIT项目假设中得到了体现：“大量低成本、低功耗的商品基础设施可以为关键的分布式应用程序形成高效的计算结构。”参与的机构和外部合作者将建立一个分布式的英国范围的轻量级计算节点联合测试平台，能够探索从这种动态基础设施中产生的研究问题。这与现有的集中式数据中心方法形成鲜明对比，后者占地数英亩，耗资数百万美元；消耗兆瓦级电力，依赖巨大的全球网络带宽。这些趋势是不可持续的，只有像树莓派这样的低成本硬件的出现才能让我们探索更好的解决方案。我们设想了一个由数万个节点组成的测试平台，这些节点在地理上分布，能够挑战远程离网场景。为了促进这一点，我们引入了微型数据中心的概念，这是一种物理上小、低功耗、低成本的计算集群，可以被推到分布式网络的边缘，从根本上改变当前集中式数据中心的模式。我们已经在多个地点建立了原型微数据中心，例如一个小型hpc集群（南安普顿大学），一个规模模型云数据中心（格拉斯哥和利物浦约翰摩尔斯大学），以及一个用于超远程互联网黑点的分散传感和通信平台（剑桥大学）。这个项目是关于将我们孤立的微数据中心连接在一起，以产生一个联合的、地理分布式的测试平台。我们目前有数百个独立的节点，并打算在整个英国学术网络中增加到数万个。这种扩展的关键挑战将是底层基础设施的管理，特别是考虑到网络结构的复杂性。例如，间歇性连接、防火墙和低带宽连接。我们将使用轻量级的管理和编排软件，结合软件定义的网络基础设施来管理我们的联合测试平台。通过这项工作，我们的目标是展示如何利用资源受限的微型数据中心作为通用平台，以资源高效和高性能的方式运行虚拟化的全网服务，并在低成本、低功耗的联合基础设施上实现“即服务”范式。

The introduction of ubiquitous low-cost, low-power compute devices, e.g. in the Internet of Things (IoT) is fundamentally changing the computational landscape. Although we already see the benefits provided by special purpose IoT devices, the true capability is only realised when we can re-purpose large numbers of distributed devices as part of a much larger federated service. This is captured in the FRUIT project hypothesis: "Massive aggregation of low-cost, low-power, commodity infrastructure can form an efficient and effective compute fabric for key distributed applications."The participating institutions and external collaborators will build a distributed UK-wide federated testbed of lightweight compute nodes capable of exploring the research issues that arise from such a dynamic infrastructure. This is in contrast to the existing centralised datacentre approach which occupies acres of land, cost millions of dollars; consumes megawatts of power and relies on a huge global network bandwidth. These trends are not sustainable and it is the emergence of low cost hardware such as the Raspberry Pi that will let us explore better solutions. We envisage a testbed comprising tens of thousands of nodes, geographically distributed and capable of challenging remote off-grid scenarios. In order to facilitate this we introduce the concept of a micro-datacentre, a physically small, low power and low cost compute cluster that can be pushed to the edge of distributed networks, fundamentally changing the current model of the centralised datacentre. We have already built prototype micro-data centres at multiple sites , for example a mini-HPC cluster (Southampton University), a scale model cloud datacentre (Glasgow and Liverpool John Moores University ),and a decentralized sensing and communication platform for ultra-remote internet blackspots (Cambridge University)This project is about connecting together our isolated micro-datacenters to produce a federated, geo-distributed testbed. We currently have hundreds of individual nodes and intend to grow this to tens of thousands across the UK academic network. The key challenge in this expansion will be the management of the underlying infrastructure, particularly given complexities in the networking fabric. For example intermittent connectivity, firewalls, and low bandwidth connections. We will use lightweight management and orchestration software, combined with software-defined networking infrastructure to manage our federated testbed. Through this work, we aim to demonstrate how resource-constrained micro-data centres can be harnessed as generic platforms to run virtualised, network-wide services in a resource-efficient and still high-performing manner, and enable the 'as-a-Service' paradigm over low-cost low-power federated infrastructures.