P-Store: Genuine Partial Replication in Wide Area Networks
Partial replication mentioned and discussed in this paper is the way to increase scalability of replicated systems where updates are applied only to a divided part of the system's sites. The replicas are designed to handle independent parts of the workload in parallel. This paper talks about P-Store that is a partial database replication protocol for wide area networks that allows transactions to optimistically execute at multiple sites and certifies transactions in genuine manner. In P-Store each transaction T is performed on one or more sites and is then licensed to assure serializability of the implementation. This certified protocol is genuine that involves sites that replicate data items read or written by T, and includes a method to reduce a convoy effect. The solution proposed and discussed in this paper is flexible and scalable. This study is divided into many sections with accurate and reliable data. In P-Store, accuracy relies on the usage of an atomic multicast service to order transactions that work on the same data items. To execute and certify each transaction, a single message is atomically multicast. This paper talks about the certification protocol that allows reducing the convoy effect by verifying non-conflicting transactions in parallel. The study states that the convoy effect of the certified protocol can be reduced when one percent of transactions are global.