Effective replica management for improving reliability and availability in edge-cloud computing environment

Abstract The multi-replica strategy can create multiple data replicas for the edge cloud system and store them in different DataNodes, which improves data availability and data service quality. However, the storage resources of DataNodes are limited and the user demand for data is time-varying, the unreasonable number of data replicas will cause a high storage burden on the file system or low data service quality. Therefore, the number of data replicas needs to be dynamically adjusted according to the actual situation. Based on this, a dynamic replica creation strategy based on the gray Markov chain is proposed. If the number of replicas needs to be increased, the newly added replicas need to be placed on the DataNodes. Considering the problem of load balancing of the DataNode during replica placement, this paper proposes a replica placement strategy based on the Fast Non-dominated Sorting Genetic algorithm. In addition, considering the problem of data replica synchronization and the data recovery of failed DataNodes in the edge cloud system, this paper proposes a delay-adaptive replica synchronization strategy and a load-balancing based replica recovery strategy. Finally, the experiments prove the effectiveness of the proposed strategies.