1.介绍
Web服务是一种用URL标识的软件系统, 它的接口界面和绑定由XML定义和描述。
2. 1) 服务组合三要素:
composition model & language;
development environment;
run-time environment.
2) a) an orchestration model:
Use process-modelling languages: UML activity diagrams, Petri-nets, state-charts, rule-based orchestration, activity hierarchies, pi-calculus.
b) data & data access model:
c) service selection model:
d) transactions:
3) BPEL4WS
3. 一个案例研究
4. 服务组合的6个热点问题: Coordination, Transcation , Context, Conversation modeling, Execution monitoring, Infrastructure.
相关经典论文: Ran, “A model for web services discovery with QoS”, 2003.
Wang, “Peer-serv: A Framework of Web Service in Peer-to-Peer
Environment”, 2003.
5. Composition approaches (本文核心部分)
5.1
Static: (MS) Biztalk, (BEA) WebLogic; |
Dynamic: (HP) e-flow, StarWSCoP; |
比较:Web Services composition (vs) Business process management:
n WS是自动的、异构的单元,它们的实现更加困难。
5.2 Model driven service composition
5.3 Declarative service composition
5.4 Automated vs. manual WS composition
5.5 Context based WS discovery & composition
6. 概括
7. 总结
现存的平台缺乏语义描述,因此可以接着在语义Web服务领域进行研究,除非Web服务组合不需要语义服务描述。