A new Prefetching-aware Data Replication to decrease access latency in cloud environment

Data replication is an effective technique that decreases retrieval time, thus reducing energy consumption in Cloud. When necessary files aren't locally available, they will be fetched from remote locations that is very high-time consuming process. Therefore, it is superior to pre-replicate the popular files. Even though few previous works considered prediction-based replication strategy, the prediction is not precise at many situations and occupies the storage. To address these challenges, a new dynamic replication strategy called Prefetching-aware Data Replication (PDR) is proposed, which determines the correlation of the data files using the file access history and pre-fetches the most popular files. So, the next time that this site requires a file, it will be locally available. In addition, due to the storage space restriction, replica replacement strategy plays a vital role. PDR strategy can ascertain the importance of valuable replicas based on the fuzzy inference system with four input parameters (i.e., number of accesses, cost of replica, the last time the replica was accessed, and data availability). Extensive experiments with CloudSim show that PDR achieves high data availability, high hit ratio, low storage and bandwidth consumption. On average PDR reduces over 35% of response time when compared to the other algorithms.