Efficient Data Management using the Session Log in DHT and its Evaluation

Distributed Hash Table (DHT) is a specialized distributed system that aims to lookup hashed identifiers efficiently in order to route messages to and from the corresponding nodes and objects. However DHTs are mechanisms sensitive to churn (the continuous and interleaved process of arrival / departure of nodes). As a result, they often cause loss of stored objects and failures in the lookup, a serious issue for all overlay networks. In this paper, we propose a dynamic replica location method using the session log in DHT. Our method can determine dynamically the effective number of replicas on session running periods among anticipate nodes. We also implemented a prototype based on an existing DHT routing algorithm, and we evaluated the performance of the prototype. Our proposed method was shown to reduce data loss and the cost for locating replication.