A Method for Microservices Handover in A Local Area Network

The trend of internet of things (IoT) makes the cloud less effective because networked control systems need low latency while cloud have high latency for processing data from sensors and devices. In that kind of situation, fog computing is introduced as the complement of cloud computing. However, unlike cloud services, fog services are limited to certain geographical area. As a consequence, fog services handover is needed in order to accommodate user’s mobility. This paper is focusing on microservices handover that follows user’s movement. The microservices installed in the current fog node are sent to another service coverage of a new fog node for continuing the same service to the users. Fog node contains a docker that runs MySQL, python script, and busybox services. When it comes to handover, docker will freeze current session and convert it to a checkpoint file. The file is created by taking a snapshot of the container, which consists of processes in memory, volume or image. The file will be sent by using secure shell (SSH) or file transfer protocol (FTP). At the destination fog node, the file will be processed in order to resume the service. The results show that delay of SSH is always higher than FTP in all experiments, in which the largest delays are 484.026 seconds for SSH protocol and 146.41 seconds for FTP protocols. As for checkpoint and restore process, those delays tend to be similar with respect to both SSH and FTP protocols but they are still affected by the size of snapshot and checkpoint file.