ABSTRACT

In this paper, we are proposing a new replica control algorithm Parent Siblings Oriented Tree Quorum Protocol (PSTQ) for the management of replicated data in distributed database system. This algorithm imposes a logical structure of tree on the set of copies of an object. The proposed protocol provides a small read quorum as well as a small write quorum while guaranteeing fault-tolerance of write operations. With this algorithm read operation is executed by reading one copy in failure-free environment. In case of failure of sites, number of data copies required for read operation increases but remains constant for subsequent failure of the sites. The less number of data copies required for write operation provide low write operation cost and high write availability.