基于可信度的组合服务自适应维护方法研究
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摘要
由于Web服务处于动态的网络环境当中,受网络的开放性以及各服务的自治性等因素的影响,容易发生服务失效和组合服务无法执行的问题。当一个组合服务中出现原子服务失效的状况时,需要及时发现失效的服务并寻找服务予以替换,从而保证组合服务系统的执行。这就要求在选择替换服务时选择一个能够尽可能长时间不会发生失效的服务,而一个服务是否容易发生失效可以通过这个服务的可信度(包括可靠性、信誉度和执行效率等相关Qos属性)反映。为了能够在维护组合服务运行时选择出不易发生服务失效的服务进行替换以维护组合服务的执行和长期有效性,本文基于服务可信度展开对组合服务的动态自适应维护研究。本文主要工作如下:
首先,为了实现基于可信度的组合服务自适应维护,在相关基础上提出了Web服务是否容易发生服务失效状况的度量标准。由于单纯的服务可靠性或者服务信誉度无法完备地对服务是否容易发生失效进行刻画,本文采用服务的可靠度、信誉度和执行效率三个属性共同来刻画服务的可信度,并利用不确定因素修正后再叠加的计算方法得到客观的服务可信度,为选择替换服务提供依据,在维护组合服务运行过程中有效防止“二次失效”现象的发生。
其次,在反馈控制思想基础上设计了基于可信度的服务自适应维护体系结构,实现服务的监测、预测和发现功能,为可信度的计算和组合服务的维护提供必要的Web服务信息,并支持动态网络环境下组合服务的动态自适应维护。
然后,将基于可信度的组合服务自适应维护过程转化为马尔可夫决策(MDP)过程,在MDP框架下设计了服务替换算法和自适应维护算法,实现组合服务的自适应维护,组合服务系统可有效降低服务响应时间和降低系统维护频率。
最后,通过仿真实验,验证了本文方法的可行性和有效性。
As the web services are in the dynamic network environment, so they are not absolutely identified, Given the impact of network’s openness, platform’s heterogeneity, communication asynchronous and component‘s autonomy, it’s very easy to occur service failure problem. When some atom service failure in a composite services, it needs perceive the failed service timely and look for new service to replace it, thus ensuring the execution of composite services. This requires to selecting a substitute service that won't have the failure problem, and a service whether prone to failure can reflect by the service creditability (Including reliability/credibility and executing efficiency and other related Qos attributes). In order to choose a service that not prone to failure in the process of composition services maintenance to maintain the composition services can execute and have long-term effectiveness. This paper will do research on dynamic adaptive maintenance of the composite services maintenance based on the service creditability. The main work is as below:
In order to realize the adaptive maintenance of composite services based on service creditability. The paper defines clearly the service creditability that it is measure show the degree the Web service prone to failure at first. As simple service reliability or credibility cannot complete measure and describe the failure tendency, so the paper adopts service reliability, credibility and processing efficiency together to describe service creditability and calculate creditability using the approach of the superposition of the above uncertain factor to get the objective service creditability value, and provide proof for choosing replacement service. Also, it can avoid service“failed again”phenomena in the process of replacement.
Next, this paper designs a service creditability adaptive maintenance structure based on feedback control idea and service creditability,to realize service monitor, predict and found function, and provide requisite Web service message for the maintenance of the composite service,and support the dynamic maintenance of composite services.
After that, take the dynamic maintenance of composite services based on service creditability as a MDP. Under the MDP construct, we design the service replacement algorithm and adaptive maintenance algorithm, to realize the feedback controller’s function, and finally realize the maintenance of composite services. The algorithm can effective lower the service response time and the system maintenance frequency.
Finally, through the simulation experiments, proved the feasibility and effectiveness of the method in this paper.
首先,为了实现基于可信度的组合服务自适应维护,在相关基础上提出了Web服务是否容易发生服务失效状况的度量标准。由于单纯的服务可靠性或者服务信誉度无法完备地对服务是否容易发生失效进行刻画,本文采用服务的可靠度、信誉度和执行效率三个属性共同来刻画服务的可信度,并利用不确定因素修正后再叠加的计算方法得到客观的服务可信度,为选择替换服务提供依据,在维护组合服务运行过程中有效防止“二次失效”现象的发生。
其次,在反馈控制思想基础上设计了基于可信度的服务自适应维护体系结构,实现服务的监测、预测和发现功能,为可信度的计算和组合服务的维护提供必要的Web服务信息,并支持动态网络环境下组合服务的动态自适应维护。
然后,将基于可信度的组合服务自适应维护过程转化为马尔可夫决策(MDP)过程,在MDP框架下设计了服务替换算法和自适应维护算法,实现组合服务的自适应维护,组合服务系统可有效降低服务响应时间和降低系统维护频率。
最后,通过仿真实验,验证了本文方法的可行性和有效性。
As the web services are in the dynamic network environment, so they are not absolutely identified, Given the impact of network’s openness, platform’s heterogeneity, communication asynchronous and component‘s autonomy, it’s very easy to occur service failure problem. When some atom service failure in a composite services, it needs perceive the failed service timely and look for new service to replace it, thus ensuring the execution of composite services. This requires to selecting a substitute service that won't have the failure problem, and a service whether prone to failure can reflect by the service creditability (Including reliability/credibility and executing efficiency and other related Qos attributes). In order to choose a service that not prone to failure in the process of composition services maintenance to maintain the composition services can execute and have long-term effectiveness. This paper will do research on dynamic adaptive maintenance of the composite services maintenance based on the service creditability. The main work is as below:
In order to realize the adaptive maintenance of composite services based on service creditability. The paper defines clearly the service creditability that it is measure show the degree the Web service prone to failure at first. As simple service reliability or credibility cannot complete measure and describe the failure tendency, so the paper adopts service reliability, credibility and processing efficiency together to describe service creditability and calculate creditability using the approach of the superposition of the above uncertain factor to get the objective service creditability value, and provide proof for choosing replacement service. Also, it can avoid service“failed again”phenomena in the process of replacement.
Next, this paper designs a service creditability adaptive maintenance structure based on feedback control idea and service creditability,to realize service monitor, predict and found function, and provide requisite Web service message for the maintenance of the composite service,and support the dynamic maintenance of composite services.
After that, take the dynamic maintenance of composite services based on service creditability as a MDP. Under the MDP construct, we design the service replacement algorithm and adaptive maintenance algorithm, to realize the feedback controller’s function, and finally realize the maintenance of composite services. The algorithm can effective lower the service response time and the system maintenance frequency.
Finally, through the simulation experiments, proved the feasibility and effectiveness of the method in this paper.
引文
[1]高阳,陈世福,陆鑫.强化学习研究综述.自动化学报,2004,30(1):86-100
[2]刘玲霞.Web服务容错关键技术研究.[国防科学技术大学博士学位论文].2006:1-2
[3]吴朝辉,邓水光,吴健等.服务计算与技术.杭州:浙江大学出版社,2009
[4] Harney J, Doshi P. Adaptive Web processes using value of changed information. Chicago,USA,Proceedings of the ICSOC,2006:179~190
[5] Radu Jurca,Walter Binder,Boi Faltings. Reliable QoS Monitoring Based on Client Feedback. Banff,Alberta,Canada,Proceedings of the WWW,2007:1003~1011
[6] Lee P A,T.Anderson.Fault tolerance:Principles and Practice.New York:Springer-Verlag,1990: 25~78
[7] Huipeng Guo,Jinpeng Huai,Huan Li,et al. KAF:Kalman filter based adaptive maintenance for dependability of composite services//Proceedings of the CAiSE. Montpellier ,France,2008: 328~342
[8] Huipeng Guo,Jinpeng Huai,Huan Li et al.ANGEL:Optimal Configuration for High Available Service Composition//Proceedings of the ICWs.Salt Lake City,USA,2007:280~287
[9] Issarny V,Tartanoglu F,Romanovsky A,et al. Coordinated forward error recovery for composite Web services. Florence,Italy,Proceedings of the SRDS,2003:167~167
[10] Birman K. et al. Adding High Availability and Autonomic Behavior to Web Services. Edinburgh,UK,Proceedings of the ICSE,2004:17~26
[11] Keqiang Wu,David J. Lilja,Haowei Bai,et al. The Applicability of Adaptive Control Theory to QoS Design: Limitations and Solutions. Denver,CA,USA,Proceedings of the IPDPS,2005: 272~272
[12]刘玲霞,武兆雪,钱源等.Web服务容错技术研究.计算机科学,2009,vol.36(1):24-28
[13]李昌盛,周娅,黄桂敏.保障运行时适应性的web服务组合框架研究.计算机系统应用,2008,vol.3:34-37
[14]徐新卫,王有远,曹永忠等.基于反射技术的Web服务失效处理.计算机工程与应用,2007,vol.43(12):6-9
[15]陈伟安,高春鸣.一种基于反馈控制的Web服务组合执行引擎设计.计算机工程与应用,2007,vol.43(29):154-158
[16] Su Myeon Kim,Marcel-Catalin Rosu. A survey of public Web services. Lecture Notes in Computer Science,2004,Vol.3182:96~105
[17]蔡宁宁,刘旭东,马殿富. WebSASE监控管理系统设计与实现.计算机应用研究,2007,vol.24(3):106-108
[18]徐伟,金蓓宏,李京等.一种基于移动Agent的复合Web服务容错模型.计算机学报,2005,vol.28(4):558-567
[19]钟读杭,齐治昌,徐锡山.基于N版本程序设计的Web服务组合可靠性优化.计算机工程与科学,2008,vol.30(6):115-118
[20]刘书雷,刘云翔,张帆等.一种服务聚合中QoS全局最优服务动态选择算法.计算机学报,2007,vol.18(3):646-656
[21]廖祝华,刘建勋,刘毅志等. Web服务发现技术研究综述.情报学报,2008,vol.27(2):186-192
[22]倪晚成,刘连臣,吴澄. We b服务组合方法综述.计算机工程,2008,vol.34(4):79-81
[23] Ardagna D,Pernici B. Adaptive Service Composition in Flexible. Processes.IEEE Trans.on Software Engineering,2007,vol.33(6):369~384
[24] Guinea S.Self-healing web service compositions. St.Louis,Missouri,USA,Proceedings of the ICSE,2005,655~658
[25]赵伟伟.基于冗余的可靠Web服务组合方法研究. [燕山大学硕士学位论文].秦皇岛:燕山大学,2009
[26]杨墨,王丽娜.基于信任容错的Web服务可靠性增强方法研究.通信学报,2010,vol.31(9):131-138
[27]胡蓉,刘建勋. Web服务组合的容错管理.计算机应用与软件,2010,vol.27(8):62-65
[28] Sandhya S.Pillai,Nanjangud C.Narendra. Optimal Replacement Policy of Services Based on Markov Decision Process.IEEE,2009,176~183
[29]汤萍萍,王红兵.基于强化学习的Web服务组合.计算机技术与发展,2008,vol.18(3):142-144
[30]陈彦萍,李增智,唐亚哲.一种满足马尔可夫性质的不完全信息下的Web服务组合方法.计算机学报,2006,vol.29(7):1076-1083
[31]张佩云,孙亚民.动态Web服务组合研究.计算机科学,2007,Vo1.34(5):4-7
[32] Cheng Zhou, Haopeng Chen, An Objective and Automatic Feedback Model for QoS Evaluation.Proceedings of the 2nd International Conference on InteractionSciences: Information Technology,Culture and Human 2009,Vol.403:1284~1289
[33]岳昆,刘惟一,王晓玲等.一种基于不确定性因素叠加的Web服务质量度量方法.计算机研究与发展,2009,vol.46(5):841-849
[34]曹科强,顾庆,任颖新.服务组合中基于DTMC的可靠性和性能分析.计算机科学,2009,vol.36(10):179-196
[35]朱锐,王怀民.可信服务组合研究综述.计算机工程与科学,2010,Vol.32(12):107-112
[36]范小芹,蒋昌俊,王俊丽等.随机Qos感知的可靠web服务组合.软件学报,2009,vol.3(20):546-555
[37]冯明正.Web服务关键技术研究. [东南大学博士学位论文].南京:东南大学,2006
[2]刘玲霞.Web服务容错关键技术研究.[国防科学技术大学博士学位论文].2006:1-2
[3]吴朝辉,邓水光,吴健等.服务计算与技术.杭州:浙江大学出版社,2009
[4] Harney J, Doshi P. Adaptive Web processes using value of changed information. Chicago,USA,Proceedings of the ICSOC,2006:179~190
[5] Radu Jurca,Walter Binder,Boi Faltings. Reliable QoS Monitoring Based on Client Feedback. Banff,Alberta,Canada,Proceedings of the WWW,2007:1003~1011
[6] Lee P A,T.Anderson.Fault tolerance:Principles and Practice.New York:Springer-Verlag,1990: 25~78
[7] Huipeng Guo,Jinpeng Huai,Huan Li,et al. KAF:Kalman filter based adaptive maintenance for dependability of composite services//Proceedings of the CAiSE. Montpellier ,France,2008: 328~342
[8] Huipeng Guo,Jinpeng Huai,Huan Li et al.ANGEL:Optimal Configuration for High Available Service Composition//Proceedings of the ICWs.Salt Lake City,USA,2007:280~287
[9] Issarny V,Tartanoglu F,Romanovsky A,et al. Coordinated forward error recovery for composite Web services. Florence,Italy,Proceedings of the SRDS,2003:167~167
[10] Birman K. et al. Adding High Availability and Autonomic Behavior to Web Services. Edinburgh,UK,Proceedings of the ICSE,2004:17~26
[11] Keqiang Wu,David J. Lilja,Haowei Bai,et al. The Applicability of Adaptive Control Theory to QoS Design: Limitations and Solutions. Denver,CA,USA,Proceedings of the IPDPS,2005: 272~272
[12]刘玲霞,武兆雪,钱源等.Web服务容错技术研究.计算机科学,2009,vol.36(1):24-28
[13]李昌盛,周娅,黄桂敏.保障运行时适应性的web服务组合框架研究.计算机系统应用,2008,vol.3:34-37
[14]徐新卫,王有远,曹永忠等.基于反射技术的Web服务失效处理.计算机工程与应用,2007,vol.43(12):6-9
[15]陈伟安,高春鸣.一种基于反馈控制的Web服务组合执行引擎设计.计算机工程与应用,2007,vol.43(29):154-158
[16] Su Myeon Kim,Marcel-Catalin Rosu. A survey of public Web services. Lecture Notes in Computer Science,2004,Vol.3182:96~105
[17]蔡宁宁,刘旭东,马殿富. WebSASE监控管理系统设计与实现.计算机应用研究,2007,vol.24(3):106-108
[18]徐伟,金蓓宏,李京等.一种基于移动Agent的复合Web服务容错模型.计算机学报,2005,vol.28(4):558-567
[19]钟读杭,齐治昌,徐锡山.基于N版本程序设计的Web服务组合可靠性优化.计算机工程与科学,2008,vol.30(6):115-118
[20]刘书雷,刘云翔,张帆等.一种服务聚合中QoS全局最优服务动态选择算法.计算机学报,2007,vol.18(3):646-656
[21]廖祝华,刘建勋,刘毅志等. Web服务发现技术研究综述.情报学报,2008,vol.27(2):186-192
[22]倪晚成,刘连臣,吴澄. We b服务组合方法综述.计算机工程,2008,vol.34(4):79-81
[23] Ardagna D,Pernici B. Adaptive Service Composition in Flexible. Processes.IEEE Trans.on Software Engineering,2007,vol.33(6):369~384
[24] Guinea S.Self-healing web service compositions. St.Louis,Missouri,USA,Proceedings of the ICSE,2005,655~658
[25]赵伟伟.基于冗余的可靠Web服务组合方法研究. [燕山大学硕士学位论文].秦皇岛:燕山大学,2009
[26]杨墨,王丽娜.基于信任容错的Web服务可靠性增强方法研究.通信学报,2010,vol.31(9):131-138
[27]胡蓉,刘建勋. Web服务组合的容错管理.计算机应用与软件,2010,vol.27(8):62-65
[28] Sandhya S.Pillai,Nanjangud C.Narendra. Optimal Replacement Policy of Services Based on Markov Decision Process.IEEE,2009,176~183
[29]汤萍萍,王红兵.基于强化学习的Web服务组合.计算机技术与发展,2008,vol.18(3):142-144
[30]陈彦萍,李增智,唐亚哲.一种满足马尔可夫性质的不完全信息下的Web服务组合方法.计算机学报,2006,vol.29(7):1076-1083
[31]张佩云,孙亚民.动态Web服务组合研究.计算机科学,2007,Vo1.34(5):4-7
[32] Cheng Zhou, Haopeng Chen, An Objective and Automatic Feedback Model for QoS Evaluation.Proceedings of the 2nd International Conference on InteractionSciences: Information Technology,Culture and Human 2009,Vol.403:1284~1289
[33]岳昆,刘惟一,王晓玲等.一种基于不确定性因素叠加的Web服务质量度量方法.计算机研究与发展,2009,vol.46(5):841-849
[34]曹科强,顾庆,任颖新.服务组合中基于DTMC的可靠性和性能分析.计算机科学,2009,vol.36(10):179-196
[35]朱锐,王怀民.可信服务组合研究综述.计算机工程与科学,2010,Vol.32(12):107-112
[36]范小芹,蒋昌俊,王俊丽等.随机Qos感知的可靠web服务组合.软件学报,2009,vol.3(20):546-555
[37]冯明正.Web服务关键技术研究. [东南大学博士学位论文].南京:东南大学,2006