An Extendible Hashing Based Recovery Method in a Shared-Nothing Spatial Database Cluster

In this paper, a recovery method using extendible hashing in a shared-nothing spatial database cluster is proposed. The purpose is to increase the recovery performance and to decrease overhead of the system. In the case of failure, the recovery method in a database cluster restores the database using replicated data from neighbor node. When detect a failure, neighbor node writes the cluster log, and it must be transferred to a failure node. However, in neighbor node, one transaction makes several logs, and increase transferring log size. Also, this increases the recovery time and overhead of the internal network. The proposed method defines a novel cluster log that is composed of update type and a pointer to a record through RID or primary key. This is managed by extendible hashing in main memory. The last transaction replaces the cluster log. Through sending of last updated data, the number of cluster logs and transaction count in failure node are decreased. As a result, the method in this paper increased the availability of the database cluster.