Formal Development Of Replica Control Protocol Using Event B

Abstract

In the everyday life, mobile and web applications are being used by greater than 5.96 billion internet users for entertainments and gaming; social and media interactions; information management and retrievals; businesses processing and retail services, etc. Due to the data volume and simultaneous users rapid growth, these applications depends on the distributed database for handling OLTP s (On-Line Transaction Processing) greater requests on the internet level. In the initial design phase of application, user-defined partitioning schemes are employed by these database so that user data s concurrent writing is scaled out into various servers that are based on shared- nothing. Although, DTs (Distributed Transactions) processing involves multiple servers data tuples which can reduce these databases performance. Additionally, database s recurrent data tuples influences the transactional patterns which results in workload s substantial changes which, in real-time, cannot be handled by any static partitioning approach. The above-mentioned challenges are addressed in this thesis with the help of incremental data repartitioning which is aware of workload. newlineThe main objective is minimal redistribution of data tuple in the system while analyzing the minimization of DT s adverse impacts without influencing the load balance of data distribution. The most challenging issue in distributed environment are concurrency control and data availability. For maintaining the data availability, data is replicated at various sites or locations, which enhances the availability, simultaneously maintaining the data consistency is further a difficult task. Therefore, for improving the system performance, it is needed that on various sites, several transactions must be executed concurrently. Thus, such concurrent transactions must be controlled for maintaining the replica s consistency. There exists more complexity in controlling the replicas in environments where because of the communication failure messages get delayed.