The paper proposes a client-centric computing model that allows for adaptive execution of service-oriented applications. The model can flexibly dispatch application tasks to the client side and the network side, dynam...The paper proposes a client-centric computing model that allows for adaptive execution of service-oriented applications. The model can flexibly dispatch application tasks to the client side and the network side, dynamically adjust an execution scheme to adapt to environmental changes, and thus is expected to achieve better scalability, higher performance and more controllable privacy. Scheduling algorithms and the rescheduling strategies are proposed for the model. Experiments show that with the model the performance of service-oriented application execution can be improved.展开更多
Business applications are subject to changes with technology trends or market demands. However, quick response to these changes is still a challenging issue. Most of the existing architectures （e.g., CORBA, Web Servi...Business applications are subject to changes with technology trends or market demands. However, quick response to these changes is still a challenging issue. Most of the existing architectures （e.g., CORBA, Web Services） still expose the developers to excessive low-level details and force a tight coupling between program modules. For end users, developing, customizing, and reengineering applications remain difficult and time-consuming tasks. A high-level programming model is presented, together with a descriptive programming paradigm called BEAP, to facilitate end-user programming. In this approach, applications could be visually composed from well-defined software components called ＂funnels＂ in an event-driven fashion. Application examples have shown that, by raising the level of abstraction as well as simplifying the programming model, BEAP could empower end users to build business applications on demand with improved productivity.展开更多
Our study introduces a novel distributed query plan refinement phase in an enhanced architecture of distributed query processing engine （DQPE）. Query plan refinement generates potentially efficient distributed query...Our study introduces a novel distributed query plan refinement phase in an enhanced architecture of distributed query processing engine （DQPE）. Query plan refinement generates potentially efficient distributed query plan by reusable aggregate query shipping （RAQS） approach. The approach improves response time at the cost of pre-processing time. If the overheads could not be compensated by query results reusage, RAQS is no more favorable. Therefore a globM cost estimation model is employed to get proper operators： RR_Agg, R_Agg, or R_Scan. For the purpose of reusing results of queries with aggregate function in distributed query processing, a multi-level hybrid view caching （HVC） scheme is introduced. The scheme retains the advantages of partial match and aggregate query results caching. By our solution, evaluations with distributed TPC-H queries show significant improvement on average response time.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos. 90412005 and 90412010.
文摘The paper proposes a client-centric computing model that allows for adaptive execution of service-oriented applications. The model can flexibly dispatch application tasks to the client side and the network side, dynamically adjust an execution scheme to adapt to environmental changes, and thus is expected to achieve better scalability, higher performance and more controllable privacy. Scheduling algorithms and the rescheduling strategies are proposed for the model. Experiments show that with the model the performance of service-oriented application execution can be improved.
基金Supported by the National Natural Science Foundation of China （Grant No. 90412010）, the National Basic Research 973 Program of China （Grant Nos. 2003CB317008 and 2005CB321807）, and the National High Technology Development 863 Program of China （Grant No. 2004AA104330）. thank the members of Vega The authors would like to Center of Institute of Computing Technology, CAS. It is their feedbacks and supports that have been inspiring and advancing the BEAP paradigm to grow up and make continuous progresses. We also feel grateful for the anonymous referees＇ comments.
文摘Business applications are subject to changes with technology trends or market demands. However, quick response to these changes is still a challenging issue. Most of the existing architectures （e.g., CORBA, Web Services） still expose the developers to excessive low-level details and force a tight coupling between program modules. For end users, developing, customizing, and reengineering applications remain difficult and time-consuming tasks. A high-level programming model is presented, together with a descriptive programming paradigm called BEAP, to facilitate end-user programming. In this approach, applications could be visually composed from well-defined software components called ＂funnels＂ in an event-driven fashion. Application examples have shown that, by raising the level of abstraction as well as simplifying the programming model, BEAP could empower end users to build business applications on demand with improved productivity.
基金partially supported by the National Basic Research 973 Program of China under Grant No. 2005CB321807the National High Technology Rresearch and Development 863 Program of China under Grant Nos. 2006AA01A106 and 2006AA04Z158.
文摘Our study introduces a novel distributed query plan refinement phase in an enhanced architecture of distributed query processing engine （DQPE）. Query plan refinement generates potentially efficient distributed query plan by reusable aggregate query shipping （RAQS） approach. The approach improves response time at the cost of pre-processing time. If the overheads could not be compensated by query results reusage, RAQS is no more favorable. Therefore a globM cost estimation model is employed to get proper operators： RR_Agg, R_Agg, or R_Scan. For the purpose of reusing results of queries with aggregate function in distributed query processing, a multi-level hybrid view caching （HVC） scheme is introduced. The scheme retains the advantages of partial match and aggregate query results caching. By our solution, evaluations with distributed TPC-H queries show significant improvement on average response time.
