A Survey on Mobility-Induced Service Migration in the Fog, Edge, and Related Computing Paradigms <s> Scope and Contributions <s> When users flood in cloud data centers, how to efficiently manage hardware resources and virtual machines (VMs) in a data center to both lower economical cost and ensure a high service quality becomes an inevitable work for cloud providers. VM migration is a cornerstone technology for the majority of cloud management tasks. It frees a VM from the underlying hardware. This feature brings a plenty of benefits to cloud providers and users. Many researchers are focusing on pushing its cutting edge. In this paper, we first give an overview of VM migration and discuss both its benefits and challenges. VM migration schemes are classified from three perspectives: 1) manner; 2) distance; and 3) granularity. The studies on non-live migration are simply reviewed, and then those on live migration are comprehensively surveyed based on the three main challenges it faces: 1) memory data migration; 2) storage data migration; and 3) network connection continuity. The works on quantitative analysis of VM migration performance are also elaborated. With the development and evolution of cloud computing, user mobility becomes an important motivation for live VM migration in some scenarios (e.g., fog computing). Thus, the studies regarding linking VM migration to user mobility are summarized as well. At last, we list the open issues which are waiting for solutions or further optimizations on live VM migration. <s> BIB001 </s> A Survey on Mobility-Induced Service Migration in the Fog, Edge, and Related Computing Paradigms <s> Scope and Contributions <s> Despite the rapid growth of hardware capacity and popularity in mobile devices, limited resources in battery and processing capacity still lack the ability to meet increasing mobile users’ demands. Both conventional techniques and emerging approaches are brought together to fill this gap between user demand and mobile devices’ limited capabilities. Recent research has focused on enhancing the performance of mobile devices via augmentation techniques. Augmentation techniques for mobile cloud computing refer to the computing paradigms and solutions to outsource mobile device computation and storage to more powerful computing resources in order to enhance a mobile device’s computing capability and energy efficiency (e.g., code offloading). Adopting augmentation techniques in the heterogeneous and intermittent mobile cloud computing environment creates new challenges for computation management, energy efficiency, and system reliability. In this article, we aim to provide a comprehensive taxonomy and survey of the existing techniques and frameworks for mobile cloud augmentation regarding both computation and storage. Different from the existing taxonomies in this field, we focus on the techniques aspect, following the idea of realizing a complete mobile cloud computing system. The objective of this survey is to provide a guide on what available augmentation techniques can be adopted in mobile cloud computing systems as well as supporting mechanisms such as decision-making and fault tolerance policies for realizing reliable mobile cloud services. We also present a discussion on the open challenges and future research directions in this field. <s> BIB002
As introduced earlier, this survey primarily focuses on mobility-induced service migration at the edge. Therefore, related contributions dealing with VM migration within or across data centers or those dealing with computation offloading from mobile devices to the cloud or to cloudlets lie out of the scope of this survey. For an overview of such contributions, the interested reader may refer to  BIB001 for the former and BIB002 for the latter. In this work, we specifically contribute in the following directions: • We identify all relevant edge-centric computing paradigms where service migration has been studied, regardless of the specific application scenario. These paradigms include cloudlets, fog computing, cloud-based vehicular networks, and multi-access edge computing. The aim is to bring together into a single place the best of the advances made in these research areas with regard to service migration. • We outline the high-level characteristics that can affect a given migration setup, therefore highlighting the most and the least commonly considered characteristics. • We provide a detailed classification of the reviewed works based on their objectives, in addition to highlighting the works where the primary focus has been on architectural design and implementation. The remainder of this article is organized as follows. Section 2 outlines the different edge-related research areas where the topic of service migration has been studied. Section 3 presents a view on the diversity in the migration scenarios landscape. Section 4 reviews some basic terms and definitions generally encountered in the literature, thus setting the ground for the detailed analysis of the taxonomy proposed in Section 5. Section 6 presents the different architectures, platforms, and implementations related to the migration at the edge. Section 7 lists the gaps identified in the reviewed literature, thus providing directions for future research. Finally, Section 8 concludes this survey.