Edge computing is a (r)evolutionary extension of traditional cloud computing. It expands central cloud infrastructure with execution environments close to the users in terms of latency in order to enable a new generation of cloud applications. This paradigm shift has opened the door for telecommunications operators, mobile and fixed network vendors: they have joined the cloud ecosystem as essential stakeholders considerably influencing the future success of the technology. A key problem in edge computing is the optimal placement of computational units (virtual machines, containers, tasks or functions) of novel distributed applications. These components are deployed to a geographically distributed virtualized infrastructure and heterogeneous networking technologies are invoked to connect them while respecting quality requirements. The optimal hosting environment should be selected based on multiple criteria by novel scheduler algorithms which can cope with the new challenges of distributed cloud architecture where networking aspects cannot be ignored. The research community has dedicated significant efforts to this topic during recent years and a vast number of theoretical results have been published addressing different variants of the related mathematical problems. However, a comprehensive survey focusing on the technical and analytical aspects of the placement problem in various edge architectures is still missing. This survey provides a comprehensive summary and a structured taxonomy of the vast research on placement of computational entities in emerging edge infrastructures. Following the given taxonomy, the research papers are analyzed and categorized according to several dimensions, such as the capabilities of the underlying platforms, the structure of the supported services, the problem formulation, the applied mathematical methods, the objectives and constraints incorporated in the optimization problems, and the complexity of the proposed methods. We summarize the gained insights and important lessons learned, and finally, we reveal some important research gaps in the current literature.

中文翻译：

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边缘及其他放置方法调查


边缘计算是传统云计算的革命性延伸。它通过在延迟方面接近用户的执行环境来扩展中央云基础设施，以支持新一代云应用程序。这种范式转变为电信运营商、移动和固定网络供应商打开了大门：他们作为重要的利益相关者加入了云生态系统，对技术未来的成功产生了重大影响。边缘计算的一个关键问题是新型分布式应用程序的计算单元（虚拟机、容器、任务或函数）的最佳放置。这些组件被部署到地理上分布的虚拟化基础设施，并调用异构网络技术来连接它们，同时尊重质量要求。应通过新颖的调度程序算法根据多个标准选择最佳托管环境，这些算法可以应对分布式云架构的新挑战，其中网络方面不容忽视。近年来，研究界为这一主题做出了巨大的努力，并发表了大量理论成果来解决相关数学问题的不同变体。然而，仍然缺乏针对各种边缘架构中布局问题的技术和分析方面的全面调查。这项调查对新兴边缘基础设施中计算实体的放置的大量研究提供了全面的总结和结构化分类。 按照给定的分类法，根据底层平台的功能、支持的服务的结构、问题的表述、应用的数学方法、优化中包含的目标和约束等几个维度对研究论文进行分析和分类问题以及所提出方法的复杂性。我们总结了所获得的见解和重要的经验教训，最后，我们揭示了当前文献中的一些重要的研究空白。