Search

With the rapid development of cloud computing technology and the broad application of the Internet, more and more user data are stored in the cloud storage system online. Data copy technology is an effective technical means to manage various data in cloud storage systems, which has the advantages of improving data access speed and enhancing data availability in cloud storage systems. Since a data copy management strategy has an important impact on the performance of cloud storage systems, how to design a data copy management strategy is of great significance to achieving high-quality cloud storage management. Firstly, this paper analyzes the HDFS random copy placement strategy and its shortcomings. Secondly, proposes a copy placement strategy based on evaluation value and load balancing. Thirdly, gives the evaluation function of rack and node by considering multiple evaluation indicators such as node disk space load capacity, node memory utilization, node CPU utilization, rack load rate and network distance between racks. Fourthly, finds suitable nodes through computer shelf evaluation values and node evaluation values when placing replicas. Finally, through simulation experiments, the experimental results of the HDFS random replica placement strategy and the evaluation results and load balancing-based replica placement strategy are compared and analyzed. [ABSTRACT FROM AUTHOR]

As a fast-rising storage model in recent years, cloud storage has adopted a "pay-as-you-go" approach to provide users with highly reliable, highly available, low-cost, and secure storage services that have received widespread attention and use within enterprises and individuals. Data replica management technology, as an essential part of cloud storage systems, has irreplaceable advantages in improving cluster fault tolerance and availability, so it has become the focus of many experts and scholars. It replicates multiple data blocks and places them in various nodes in the cluster; this makes the data more secure and reliable and improves the access rate while ensuring system load balance. Data replica technology runs through the process from replica creation to consistency maintenance. Each part of it has an essential impact on the performance of the cloud storage system. This article focuses on the dynamic decision of the number of data replicas in the cloud storage system. Considering the shortcomings of the static replica strategy, a dynamic decision strategy for the number of replicas based on the popularity of the data is proposed. By using the gray prediction model GM (1, 1) to predict the future data access frequency and using the Markov model to modify the prediction result, the data can be divided into hot data and non-hot data according to the predicted value, thereby determining the data replica number. Finally, through simulation experiments, the experimental results of the static replica strategy and the data hot-based replica number dynamic decision strategy are compared and analyzed. [ABSTRACT FROM AUTHOR]

With the spread of cloud storage technology, checking the integrity of data stored in the cloud effectively is increasingly becoming a concern. Following the introduction of the first remote data integrity audit schemes, different audit schemes with various characteristics have been proposed. However, most of the existing solutions have problems such as additional storage overhead and additional certificate burden. This paper proposes a certificateless remote data integrity auditing scheme which takes into account the storage burden and data privacy issues while ensuring the correctness of the data audit results. In addition, the certificateless design concept enables the scheme proposed in this paper to avoid a series of burdens brought by certificates. The scheme designed in this paper provides a data access control function whereby only users who hold a valid token generated by the data owner can access the target data from the cloud. Finally, this paper provides a detailed security proof to ensure the rationality of the results. A theoretical analysis and subsequent experimental verification show that the proposed scheme is both effective and feasible. [ABSTRACT FROM AUTHOR]

Deduplication is a popular data reduction technology in storage systems which has significant advantages, such as finding and eliminating duplicate data, reducing data storage capacity required, increasing resource utilization, and saving storage costs. The file features are a key factor that is used to calculate the similarity between files, but the similarity calculated by the single feature has some limitations especially for the similar files. The storage node feature reflects the load condition of the node, which is the key factor to be considered in the data routing. This paper introduces a multifeature data routing strategy (DRMF). The routing strategy is made based on the features of the cluster, including routing communication, file similarity calculation, and the determination of the target node. The mutual information exchange is achieved by routing communication, routing servers, and storage nodes. The storage node calculates the similarity between the files stored, and then the file is routed according to the information provided by the routing server. The routing server determines the target node of the route according to the similar results and the node load features. The system prototype is designed and implemented; also, we develop a system to process the feature of cluster and determine the specific parameters of various features of experiments. In the end, we simulate the multifeature data routing and single-feature data routing, respectively, and compare the deduplication rate and data slope between the two strategies. The experimental results show that the proposed data routing strategy using multiple features can improve the deduplication rate of the cluster and maintain a lower data skew rate compared with the single-feature-based routing strategy MCS; DRMF can improve the deduplication rate of the cluster and maintain a lower data skew rate. [ABSTRACT FROM AUTHOR]

The dramatic increase of storage devices in distributed storage cluster system and the inherent characteristics of distributed deployment mode make network resources become one of the bottlenecks of data storage process. By analyzing the functional characteristics of data flow transmission of the components of the storage system, the network topology structure of the storage system is constructed, and the evaluation index of node flow load is put forward based on the degree centrality and the betweenness centrality theory of the network to explore the network topology and real-time flow characteristics. According to the evaluation index of node flow load, a network-aware data layout scheme is proposed. By balancing the flow load of bottleneck link, congestion and transmission delay can be reduced to further shorten the total task execution time and improve the efficiency of data writing. [ABSTRACT FROM AUTHOR]

• In this paper, we revisit the CL-PDP scheme proposed by Wang et al. in 2017 since their protocol is attacked in recent work of Liao et al. We modify their original scheme and hence obtain a twisted one. • We also find out Want et al.'s security model is not proper because they merged the CSP and KGC into one entity. In our new security model, we prove that the twisted HKWWC-protocol is secure. Certificateless provable data possession (CL-PDP) protocol is an important tool to check the integrity of data outsourced to cloud service provider (CSP) since it is not necessary to consider the certificate management and key escrow problems. In 2017, He et al. proposed an efficient CL-PDP protocol (HKWWC-protocol, for short) with an additional good property: Privacy protection from the verifier Appl. Math. Comput., vol. 314, pp. 31-43. However, recently, Liao et al. illustrates that the HKWWC-protocol is completely insecure under their suggested attack (LLON-attack) since CSP can return a forged proof that is able to pass the verification of the verifier, which shows that the HKWWC-protocol will become completely useless. In this paper, we revisit the original HKWWC-protocol and try to rescue it. After our modification, the twisted new protocol can be immune to the LLON-attack. More importantly, we find that the original He et al.'s security model cannot depict the practical scene at all because they viewed CSP and KGC (key generation center) as one entity in their system. Hence, we redefine a new security model and prove the twisted HKWWC-protocol is secure under our new security model. Performance analysis shows that our proposed protocol is still efficient and practical. [ABSTRACT FROM AUTHOR]