In the ever-evolving landscape of computing, the advent of edge and fog computing has revolutionized data processing by bringing it closer to end-users. While cloud computing offers numerous advantages, including mobility, flexibility and scalability, it introduces challenges such as latency. Fog and edge computing emerge as complementary solutions, bridging the gap and enhancing services' proximity to users. The pivotal challenge addressed in this paper revolves around optimizing the placement of application microservices to minimize latency in the cloud-to-edge continuum, where a proper node selection may influence the app's performance. Therefore, this task gains complexity due to the paradigm shift from monolithic to microservices-based architectures. Two distinct placement approaches, app-based and service-based, are compared through four different placement algorithms based on criteria such as link latency, node resources, and gateway proximity. App-based allocates all the services of one app sequentially, while service-based allocates one service of each app at a time. The study, conducted using YAFS (Yet Another Fog Simulator), evaluates the impact of these approaches on latency and load balance. The findings consistently confirm the hypothesis that strategies utilizing a service-based approach outperformed or performed equally well compared to app-based approaches, offering valuable insights into trade-offs and performance differences among the algorithms and each approach in the context of efficient microservices placement in cloud-to-edge environments.

翻译：在计算领域不断演进的背景下，边缘计算与雾计算的兴起通过将数据处理移至更接近终端用户的位置，彻底变革了数据处理模式。尽管云计算具备移动性、灵活性和可扩展性等诸多优势，但其也引入了诸如延迟等挑战。雾计算与边缘计算作为互补性解决方案应运而生，弥合了云端与用户间的距离，增强了服务的就近性。本文解决的核心挑战在于优化应用微服务的部署位置，以最小化云边连续体中的延迟——其中恰当的节点选择可能显著影响应用性能。由于架构范式正从单体式向微服务式转变，该任务变得尤为复杂。本研究通过四种基于链路延迟、节点资源和网关邻近度等标准的部署算法，对比了两种不同的部署方法：基于应用的部署与基于服务的部署。基于应用的方法按顺序分配单个应用的所有服务，而基于服务的方法则每次为每个应用分配一个服务。利用YAFS（Yet Another Fog Simulator）仿真器开展的研究评估了这些方法对延迟和负载均衡的影响。研究结果持续验证了以下假设：采用基于服务策略的方法在性能上优于或等同于基于应用的方法，为云边环境中高效微服务部署的算法权衡与性能差异提供了重要见解。