Research Of Security Multi-database Access Middleware Technology With QoS Requirements

Most applications are based on the data access directly to the database by the way of sending SQL request or calling database stored procedures, then get the results back. Once a database is transplanted, much time and energy will be spent to modify the codes of the procedure to reconnect the database, some problems will arise from implementation in different geographical databases of many joint operations, transactions-processing over multi-databases, and data synchronization, etc. The maximum limit of connections directly affect the number of users and service quality. A large number of concurrent operations of opening and closing the database connections will cost a lot of time and system resources. When the number of connections reaches the maximum limit, the users can not access the database and not be guaranteed quality of service. The database connection pool is designed for giving a unified management of connectivity and access for multi-databases and taking full advantage of multiplexing to connection resources and optimizing the efficiency of connections to access database. QoS-based Databases-Access Middleware Prototype is put forward for the problems. The middleware can be based on users' privileges to connect to access the database. When the number of connections arrives at the maximum limit, the middleware can deprive of, refuse, or allocate connections to the users for accessing to databases by connections-reusing of Deprivation whit QoS Requirements algorithm just for meeting the QoS needs of different users. At the same time, the model ensure data security through the encryption in database, and the process of data transmission and communication.The main topics of research and innovation in the following areas:1) Design a common data access mechanisms, which can give a unified, efficient management of connectivity and access for multi-databases.2) Design a generic database connection pool, to achieve controllability of each connection. And design the strategies of management, maintenance, distribution, release, reuse, deprived of for all connections in the pool. 3) The management of connections of deprivation based on the requirement of QoS is adopted to achieve more effective and flexible control of the databases connections. When many users to simultaneously access the database, if the number of connections has reached the maximum limit, the middleware will give a efficient way to maintain and manage the connections based on users' privileges by the connections-reuse of deprivation algorithm. When the number of users who access to the middleware reach the maximum number of connections and users with superior privileges request to access to connect the middleware at the same time, the middleware layer will adopt the strategy of connections-reuse of deprivation to deprive of the connections with inferior privileges and give the connections to users with superior privileges based on the users' privileges, and complete the reuse of connections which are deprived of by the connection-reuse of deprivation algorithm.4)Data access middleware can be independent of the database-servers and clients, so appropriate protocol must be designed for correct communication, and also can process the data back to the clients, including data synthesis, etc., and carry out some secure controls effectively.