Cost-Effective Replication Schemes for Query Load Balancing in DHT-Based Peer-to-Peer File Searches

Abstract

In past few years, distributed hash table (DHT)-based P2P systems have been proven to be a promising way to manage decentralized index information and provide efficient lookup services. However, the skewness o regarding keywords contained in a multi-keyword query causes a query load imbalance that combines both routing and response load. This imbalance means long file retrieval latency that negatively influences the overall system performance. Although index replication has a great potential for alleviating this problem, existing schemes did not explicitly address it or incurred high cost. To overcome this issue, we propose, in this paper, an integrated solution that consists of three replication schemes to alleviate query load imbalance while minimizing the cost. The first scheme is an active index replication that is used in order to decrease routing load in the system and to distribute response load of an index among peers that store replicas of the index. The second scheme is a proactive pointer replication that places location information of each index to a predetermined number of peers for reducing maintenance cost between the index and its replicas. The third scheme is a passive index replication that guarantees the maximum query load of peers. The result of simulations indicates that the proposed schemes can help alleviate the query load imbalance of peers. Moreover, it was found by comparison that our schemes are more cost-effective on placing replicas than PCache and EAD.

A Node Virtualization Scheme for Structured Overlay Networks Based on Multiple Different Time Intervals

“…As another limitation of the proposed scheme, a specific physical node failure immediately affects the multiple virtual nodes assigned to the failure node. To enhance the reliability and feasibility of overlay networks, the related techniques have also been researched [28][29][30][31][32][33][34][35][36][37][38]. First, a variety of replication schemes, such as path replication, have been proposed for unstructured P2P networks [28], where nodes search for content by forwarding queries to publishing nodes via neighboring links; and the path replication schemes replicate the replied content on the nodes between the publishing and requesting nodes.…”

A shareable keyword search over encrypted data in cloud computing

“…It may take a lot of time for a user to find that particular file. Therefore, the capability of searching keywords in file content is quite important to users [2]. Searching in plaintext content is not difficult, but it is not secure if doing so.…”

User Verifiable Multiple Keyword Search Scheme using the Merkle Tree for Outsourced Data in the Cloud

“…Zheng et al (2014) suggested Verifiable Attribute-Based Keyword Search (VABKS) which enables only user-satisfying access policies to retrieve documents from the cloud. Cao et al (2014) proposed replication schemes, such as active index replication, proactive pointer replication, and passive index replication to improve query load imbalance. Yang et al (2015) proposed a hybrid technique for preserving the privacy of medical data.…”

“…User Verifiable Multiple Keyword Search Scheme using the Merkle Tree for Outsourced Data in the Cloud Searches over encrypted data with keywords (Cao et al, 2014) enables users registered with clients to retrieve the necessary file without the intervention of the client or verification by a third-party. Verifiable computation plays a major role in identifying the fraudulent activities of any third-party users on the server.…”