A Survey on Mobility-Induced Service Migration in the Fog, Edge, and Related Computing Paradigms <s> Multipath TCP-Based Optimizations. <s> Techniques using a nearby virtual machine (VM) based cloudlet have been proposed for mobile cloud computing (MCC) to enhance the performance of real-time resource-intensive mobile applications. After a mobile device (MD) discovers a cloudlet in the vicinity, it takes time to set up a VM inside the cloudlet before data offloading from the MD to the VM starts. The time between discovering the cloudlet and actual offloading of data is considered as a service initiation time. When multiple cloudlets are presented in a nearby geographical location, initiating a service with each cloudlet may be frustrating for cloudlet users when changing location. In order to eliminate the delay caused by the service initiation time after moving away from the source cloudlet, this paper proposed a seamless live VM migration between neighbour cloudlets. A seamless live VM migration is achieved with the prior knowledge of the migrating VM IP address in the destination cloudlet and more importantly with multipath TCP (MPTCP). We have performed a number of experiments to validate the proposed approach using the Linux KVM hyper visor. The experimental results demonstrate the feasibility of the proposed approach and also performance improvement. Specifically, there is zero downtime at the destination cloudlet after the migration is completed. <s> BIB001 </s> A Survey on Mobility-Induced Service Migration in the Fog, Edge, and Related Computing Paradigms <s> Multipath TCP-Based Optimizations. <s> The growing popularity of mobile devices and Internet of Things (IoT) has inspired the advent of the Cloudlet concept—a "small data center" close to users at the edge. It is believed that the Quality of Experience (QoE) of end users would greatly improve if they can access required resources within a one-hop distance from Cloudlet servers. Over the years, many researchers have proposed using virtual machines (VMs) as such service-provisioning servers. However, seeing the potentiality of containers—a lightweight virtualization tool, this paper adopts LXC containers as Cloudlet platforms. To facilitate container migration between Cloudlets, CRIU (Checkpoint/Restore in Userspace) has been chosen as the migration tool. Since the migration process goes through the Wide Area Network (WAN), which may experience congestion or network failures, this paper adopts the MPTCP (Multipath TCP) protocol to address the challenge. The multiple subflows established within a MPTCP connection can improve the resilience of the migration process and reduce migration time. We have conducted a number of experiments to validate the proposed approach. The experimental results show that LXC containers are suitable candidates for the problem and MPTCP protocol is effective in enhancing the migration process. <s> BIB002 </s> A Survey on Mobility-Induced Service Migration in the Fog, Edge, and Related Computing Paradigms <s> Multipath TCP-Based Optimizations. <s> Edge clouds are emerging as a popular paradigm of computation. In edge clouds, computation and storage can be distributed across a large number of locations, allowing applications to be hosted at the edge of the network close to the end-users. Virtual machine live migration is a key mechanism which enables applications to be nimble and nomadic as they respond to changing user locations and workload. However, VM live migration in edge clouds poses a number of challenges. Migrating VMs between geographically separate locations over slow wide-area network links results in large migration times and high unavailability of the application. This is due to network reconfiguration delays as user traffic is redirected to the newly migrated location. In this paper, we propose the use of multi-path TCP to both improve VM migration time and network transparency of applications. We evaluate our approach in a commercial public cloud environment and an emulated lab based edge cloud testbed using a variety of network conditions and show that our approach can reduce migration times by up to 2X while virtually eliminating downtimes for most applications. <s> BIB003
Another approach to reduce the overall migration delay consists of using Multipath TCP (MPTCP). MPTCP relies on the simultaneous use of multiple interfaces, thus allowing to send data across different subflows [63] . This is particularly beneficial to improve the resilience of the migration in edge-centric environments, since migration is performed over WAN links that may suffer from congestion or failures issues BIB002 . One of the relevant works in this area can be found in BIB001 , where the live VM migration across WAN-connected cloudlets is considered. The proposed migration approach combines MPTCP with the preconfiguration of the VM IP address at the destination. Experiments on Linux KVM  show that the proposed approach eliminates the service downtime. This approach has also been used in BIB003 to parallelize the VM migration, leveraging the aggregate throughput provided by MPTCP. Apart from VM migration, MPTCP has also been proposed for LXC container migration in BIB002 , where the experimental results show the efficiency of this method in reducing the migration times.