期刊名称：International Journal of Computer Science & Technology
印刷版ISSN：2229-4333
电子版ISSN：0976-8491
出版年度：2012
卷号：3
期号：2
页码：29-34
语种：English
出版社：Ayushmaan Technologies
摘要：Current applications, such as Web-based services, electronic commerce, mobile telecommunication systems, etc. are distributed in nature and manipulate time-critical databases. In order to enhance the performance and the availability of such applications, the major issue is to develop efficient protocols that cooperate with the scheduler to manage the overload of the distributed system. In order to help Real-Time Database Management Systems (RTDBS) to maintain data logical consistency while attempting to enhance concurrency execution of transactions. In this paper, we present a protocol that uses a new notion called importance value which is associated with each real-time transaction. Under conditions of overload, this value is used to select the most important transactions with respect to the application transactions in order to pursue their execution ; the other transactions are aborted. Our protocol RCCOS (Replica Concurrency-Control for Overloaded Systems) augments the protocol MIRROR, a concurrency control protocol designed for firm-deadline applications operating on replicated real-timedatabases in order to manage efficiently transactions when the distributed system is overloaded This paper, we also introduce a Transactional Multimode Model to let the application transactions adapt their behavior to the overload consequences which cannot be handled by importance protocols leading to degraded performance.
