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391
A Survey of Automated Web Service Composition Methods
- In Proceedings of the First International Workshop on Semantic Web Services and Web Process Composition, SWSWPC 2004
, 2004
"... Abstract. In today’s Web, Web services are created and updated on the fly. It’s already beyond the human ability to analysis them and generate the composition plan manually. A number of approaches have been proposed to tackle that problem. Most of them are inspired by the researches in cross-enterpr ..."
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Cited by 253 (1 self)
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Abstract. In today’s Web, Web services are created and updated on the fly. It’s already beyond the human ability to analysis them and generate the composition plan manually. A number of approaches have been proposed to tackle that problem. Most of them are inspired by the researches in cross-enterprise workflow and AI planning. This paper gives an overview of recent research efforts of automatic Web service composition both from the workflow and AI planning research community. 1
Analysis of Interacting BPEL Web Services
, 2004
"... This paper presents a set of tools and techniques for analyzing interactions of composite web services which are specified in BPEL and communicate through asynchronous XML messages. We model the interactions of composite web services as conversations, the global sequence of messages exchanged by the ..."
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Cited by 235 (13 self)
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This paper presents a set of tools and techniques for analyzing interactions of composite web services which are specified in BPEL and communicate through asynchronous XML messages. We model the interactions of composite web services as conversations, the global sequence of messages exchanged by the web services. As opposed to earlier work, our tool-set handles rich data manipulation via XPath expressions. This allows us to verify designs at a more detailed level and check properties about message content. We present a framework where BPEL specifications of web services are translated to an intermediate representation, followed by the translation of the intermediate representation to a verification language. As an intermediate representation we use guarded automata augmented with unbounded queues for incoming messages, where the guards are expressed as XPath expressions. As the target verification language we use Promela, input language of the model checker SPIN. Since SPIN model checker is a finite-state verification tool we can only achieve partial verification by fixing the sizes of the input queues in the translation. We propose the concept of synchronizability to address this problem. We show that if a composite web service is synchronizable, then its conversation set remains same when asynchronous communication is replaced with synchronous communication. We give a set of su#cient conditions that guarantee synchronizability and that can be checked statically. Based on our synchronizability results, we show that a large class of composite web services with unbounded input queues can be completely verified using a finite state model checker such as SPIN.
HTN Planning for Web Service Composition Using SHOP2
, 2004
"... Automated composition of Web Services can be achieved by using AI planning techniques. Hierarchical Task Network (HTN) planning is especially well-suited for this task. In this paper, we describe how HTN planning system SHOP2 can be used with OWL-S Web Service descriptions. We provide a sound and co ..."
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Cited by 191 (3 self)
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Automated composition of Web Services can be achieved by using AI planning techniques. Hierarchical Task Network (HTN) planning is especially well-suited for this task. In this paper, we describe how HTN planning system SHOP2 can be used with OWL-S Web Service descriptions. We provide a sound and complete algorithm to translate OWL-S service descriptions to a SHOP2 domain. We prove the correctness of the algorithm by showing the correspondence to the situation calculus semantics of OWL-S. We implemented a system that plans over sets of OWL-S descriptions using SHOP2 and then executes the resulting plans over the Web. The system is also capable of executing information-providing Web Services during the planning process. We discuss the challenges and difficulties of using planning in the information-rich and human-oriented context of Web Services.
Automatic Composition of e-Services that Export their Behavior
- IN 1ST INTL. CONFERENCE ON SERVICE ORIENTED COMPUTING
, 2003
"... The main focus of this paper is on automatic e-Service composition. We start by developing a framework in which the exported behavior of an e-Service is described in terms of its possible executions (execution trees). Then we specialize the framework to the case in which such exported behavior (i. ..."
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Cited by 180 (22 self)
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The main focus of this paper is on automatic e-Service composition. We start by developing a framework in which the exported behavior of an e-Service is described in terms of its possible executions (execution trees). Then we specialize the framework to the case in which such exported behavior (i.e., the execution tree of the e-Service) is represented by a finite state machine. In this specific setting, we analyze the complexity of synthesizing a composition, and develop sound and complete algorithms to check the existence of a composition and to return one such a composition if one exists. To the best of our knowledge, our work is the first attempt to provide an algorithm for the automatic synthesis of e-Service composition, that is both proved to be correct, and has an associated computational complexity characterization.
Model-based verification of web service compositions
, 2003
"... In this paper we discuss a model-based approach to verifying web service compositions for web service implementations. The approach supports verification against specification models and assigns semantics to the behavior of implementation models so as to confirm expected results for both the designe ..."
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Cited by 180 (12 self)
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In this paper we discuss a model-based approach to verifying web service compositions for web service implementations. The approach supports verification against specification models and assigns semantics to the behavior of implementation models so as to confirm expected results for both the designer and implementer. Specifications of the design are modeled in UML, in the form of Message Sequence Charts (MSCs), and mechanically compiled into the Finite State Process notation (FSP) to concisely describe and reason about the concurrent programs. Implementations are mechanically translated to FSP to allow a trace equivalence verification process to be performed. By providing early design verification, the implementation, testing and deployment of web service compositions can be eased through the understanding of the differences, limitations and undesirable traces allowed by the composition. The approach is supported by a suite of cooperating tools for specification, formal modeling and trace animation of the composition workflow.
Conversation specification: a new approach to design and analysis of e-service composition
- In World Wide Web Conference
, 2003
"... This paper introduces a framework for modeling and specifying the global behavior of e-service compositions. Under this framework, peers (individual e-services) communicate through asynchronous messages and each peer maintains a queue for incoming messages. A global “watcher ” keeps track of message ..."
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Cited by 175 (28 self)
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This paper introduces a framework for modeling and specifying the global behavior of e-service compositions. Under this framework, peers (individual e-services) communicate through asynchronous messages and each peer maintains a queue for incoming messages. A global “watcher ” keeps track of messages as they occur. We propose and study a central notion of a “conversation”, which is a sequence of (classes of) messages observed by the watcher. We consider the case where the peers are represented by Mealy machines (finite state machines with input and output). The sets of conversations exhibit unexpected behaviors. For example, there exists a composite e-service based on Mealy peers whose set of conversations is not context free (and not regular). (The set of conversations is always context sensitive.) One cause for this is the queuing of messages; we introduce an operator “prepone ” that simulates queue
Automated Composition of Semantic Web Services into Executable Processes
, 2004
"... Different planning techniques have been proposed so far which address the problem of automated composition of web services. However, in realistic cases, the planning problem is far from trivial: the planner needs to deal with the nondeterministic behaviour of web services, the partial observability ..."
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Cited by 170 (5 self)
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Different planning techniques have been proposed so far which address the problem of automated composition of web services. However, in realistic cases, the planning problem is far from trivial: the planner needs to deal with the nondeterministic behaviour of web services, the partial observability of their internal status, and with complex goals, e.g., expressing temporal conditions and preference requirements. We propose...
Automating DAML-S Web Services Composition using SHOP2
- In Proc. of ISWC2003
, 2003
"... Abstract. The DAML-S Process Model is designed to support the ap-plication of AI planning techniques to the automated composition of Web services. SHOP2 is an Hierarchical Task Network (HTN) planner well-suited for working with the Process Model. We have proven the cor-respondence between the semant ..."
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Cited by 155 (6 self)
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Abstract. The DAML-S Process Model is designed to support the ap-plication of AI planning techniques to the automated composition of Web services. SHOP2 is an Hierarchical Task Network (HTN) planner well-suited for working with the Process Model. We have proven the cor-respondence between the semantics of SHOP2 and the situation calculus semantics of the Process Model. We have also implemented a system which soundly and completely plans over sets of DAML-S descriptions using a SHOP2 planner, and then executes the resulting plans over the Web. We discuss the challenges and difficulties of using SHOP2 in the information-rich and human-oriented context of Web services. 1
Current solutions for web service composition
- IEEE Internet Computing
, 2004
"... Web service composition lets developers create applications on top of serviceoriented computing’s native description, discovery, and communication capabilities. Such applications are rapidly deployable and offer developers reuse possibilities and users seamless access to a variety of complex service ..."
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Cited by 153 (4 self)
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Web service composition lets developers create applications on top of serviceoriented computing’s native description, discovery, and communication capabilities. Such applications are rapidly deployable and offer developers reuse possibilities and users seamless access to a variety of complex services. There are many existing approaches to service composition,ranging from abstract methods to those aiming to be industry standards. The authors describe four key issues for Web service composition. In service-oriented computing (SOC), developers use services as fundamental elements in their application-development processes. Services are platform- and network-independent operations that clients or other services invoke. To operate in an SOC environment, services must overtly define their properties in a standard, machine-readable format. SOC thus offers three native capabilities: description, discovery, and communication. 1 Web services are a typical SOC example: developers implement SOC native capabilities
Web Service Composition - Current Solutions and Open Problems
- In: ICAPS 2003 Workshop on Planning for Web Services
, 2003
"... Composition of Web services has received much interest to support business-to-business or enterprise application integration. On the one side, the business world has developed a number of XML-based standards to formalize the specification of Web services, their flow composition and execution. This a ..."
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Cited by 147 (1 self)
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Composition of Web services has received much interest to support business-to-business or enterprise application integration. On the one side, the business world has developed a number of XML-based standards to formalize the specification of Web services, their flow composition and execution. This approach is primarily syntactical: Web service interfaces are like remote procedure call and the interaction protocols are manually written. On the other side, the Semantic Web community focuses on reasoning about web resources by explicitly declaring their preconditions and effects with terms precisely defined in ontologies. For the composition of Web services, they draw on the goal-oriented inferencing from planning. So far, both approaches have been developed rather independently from each other. We compare these approaches...
