DOCSLIB.ORG

Restful Based Heterogeneous Geoprocessing Workflow

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Restful Based Heterogeneous Geoprocessing Workflow Computers & Geosciences 47 (2012) 102–110 Contents lists available at SciVerse ScienceDirect Computers & Geosciences journal homepage: www.elsevier.com/locate/cageo RESTFul based heterogeneous Geoprocessing workflow interoperation for Sensor Web Service Chao Yang a,b, Nengcheng Chen a, Liping Di b,n a State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, 129 Luoyu Road, Wuhan, Hubei 430079, China b Center for Spatial Information Science and Systems, George Mason University, 4400 University Drive, MSN 6E1, Fairfax, VA 22030, USA article info abstract Article history: Advanced sensors on board satellites offer detailed Earth observations. A workflow is one approach for Received 19 March 2011 designing, implementing and constructing a flexible and live link between these sensors’ resources and Received in revised form users. It can coordinate, organize and aggregate the distributed sensor Web services to meet the 1 September 2011 requirement of a complex Earth observation scenario. Accepted 7 November 2011 A RESTFul based workflow interoperation method is proposed to integrate heterogeneous work- Available online 15 November 2011 flows into an interoperable unit. The Atom protocols are applied to describe and manage workflow Keywords: resources. The XML Process Definition Language (XPDL) and Business Process Execution Language RESTFul (BPEL) workflow standards are applied to structure a workflow that accesses sensor information and Workflow interoperation one that processes it separately. Then, a scenario for nitrogen dioxide (NO ) from a volcanic eruption is OGC Web Services 2 used to investigate the feasibility of the proposed method. The RESTFul based workflows interoperation NO2 system can describe, publish, discover, access and coordinate heterogeneous Geoprocessing workflows. & 2011 Elsevier Ltd. All rights reserved. 1. Introduction (EML) (Everding and Echterhoff, 2008). The service specifications for sensors connected to the Web are mainly the Sensor Planning 1.1. Sensor Web Enablement Service (SPS) (Simonis, 2007), the Web Notification Service (WNS) (Simonis and Echterhoff, 2006), the Sensor Alert Service (SAS) The OpenGIS Web Service (OWS) framework, which is speci- (Simonis, 2006) and the Sensor Observation Service (SOS) (Na and fied by the Open Geospatial Consortium (OGC), provides a series Priest, 2007). of common Web service architectures and standards for geospa- tial information interchange and interoperation. Through these 1.2. Workflow technique for Sensor Web 2.0 specifications, isolated information is expanded into accessible Web resources and user can obtain information through distrib- In the Sensor Web 2.0 (Mandl et al., 2008) software architecture, uted Web services. the Sensor Web combines sensors and sensor networks with a In a sensor Web environment, sensors and sensor resources Service-Oriented Architecture (SOA), which allows users to discover, are distributed and heterogeneous. The Sensor Web Enablement describe and invoke services from a heterogeneous software plat- (SWE) specifications are the subset of OWS specifications that form via a series of technology such as eXtensive Makeup Language aims to create an integrated geospatial Sensor Web network (XML), Simple Object Access Protocol (SOAP) or Web Service where all types of sensors, instruments, imaging devices and Description Language (WSDL) and various workflow standards repositories of sensor data are discoverable, accessible, applicable applied in converting the Sensor Web into a desirable geospatial and controllable. workflow (or a geospatial process chain) (Chen et al., 2010a). The SWE consists of a sensor information model and a number of workflow is designed to describe the whole sensor knowledge sensor Web specifications. The information model contains four transfer process from raw sensor observations to informational parts: SensorML (Botts and Robin, 2007), Observation and Mea- products. This process connects a series of operation steps from surements (O&M) (Cox, 2007a, 2007b), Transducer Markup Lan- serving planning and observations, through data processing and guage (TML) (Havens, 2007) and Event pattern Markup Language information managing (Chen et al., 2010b). Currently, there are two main workflow industry structural and technical standards in the Web workflow applications field: an n Corresponding author. Tel.: þ1 703 993 6114; fax: þ1 703 993 6127. XML-based workflow description language (mostly in XML Process E-mail address: [email protected] (L. Di). Definition Language (XPDL) and Web Service Flow Language 0098-3004/$ - see front matter & 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.cageo.2011.11.010 C. Yang et al. / Computers & Geosciences 47 (2012) 102–110 103 (WSFL)) and the Business Process Execution Language (BPEL). XPDL (Rosenberg et al., 2008). Under the SOA environment, the work- is a Workflow Management Coalition (WfMC) standard for inter- flows are applied as Web Services, the interoperation of work- changing business process definitions between different workflows flows built on the interface chaining. Although there are or Web Services. BPEL is an industry standard executable language numerous transgressions in daily Web practice, the consensus for orchestrating Web Services into business processes. of the Web development community backs the resource-oriented A XPDL design workflow uses an XML-based syntax and is paradigm proposed by the REST model. The simplicity of the specified by an XML schema. The workflow’s components and single interface, single protocol (HTTP methods) approach has actions are both described as ‘‘Elements’’. As a standard workflow potential benefit in complex scenarios. modeling language, XPDL endorses process definition visualiza- With the explosion of Earth observation information, the trend tion and the XPDL based process supports more than 20 kinds of is to organize individual Sensor Web Services into aggregated workflow patterns. geospatial workflows to offer advanced operations for complex Unlike XPDL, BPEL is primarily concerned with the Web service application scenarios. Because the workflows vary in character it is orchestration, BPEL has its own XML based programming syntax, hard to interoperate them in a unified workflow engine. Usually, with commands such as ‘‘receive’’, ‘‘reply’’ and ‘‘invoke’’ for control- the solution under the SOA framework is that workflows are sealed ling the basic workflow process unit—‘‘Activities’’, which directs the and exposed as Web service interfaces for future interoperation. interoperation of different Web servicesandisdescribedonlybya This paper focuses on the interoperation of heterogeneous geos- series of connection subelements in a BPEL process. BPEL itself patial workflows in the Sensor Web environment using the REST- defines the syntax for an XML-based programming language. Thus, Ful method. As opposed to the Web service chaining model in the Web Services can be organized and directed in an order, which is SOA, this paper abstracts and presents the concrete workflow significant in complex Web service integration. As they differ in process as a virtual process. This process can be published and structure and operation model, transfer between an XPDL process fed as a Web resource; the resource can be created, accessed and and BPEL process workflow is hard to achieve. operated by users and then the process executed in a specific workflow engine. 1.3. REST architecture and RESTFul Web workflow In Section 2, workflow technology and the RESTFul architec- ture style are introduced as the base of the RESTFul geospatial The Representational State Transfer (REST) (Fielding, 2000)isa Workflow Interoperation System (RWIS). In Section 3, workflow styleofsoftwarearchitecturefordistributedhypermediasystems interoperation technique details of RWIS and heterogeneous such as the World Wide Web. Distributed Web content is described Sensor Web workflow instances (XPDL based sensor information as a Web resource. The RESTFul Web service (Richardson and Ruby, accessing workflow and the BPEL sensor information processing 2007) is gaining increased attention because of this simple Web workflow separately) are described. Then, the benefits of the service publishing and consuming: distributed Web Services are RWIS architecture, work pattern and evaluation of the on-demand described and referenced as Web resources with a global identifier environment observation and monitoring under the Sensor Web (e.g., a URI in HTTP), applying HTTP method (e.g., POST, GET, PUT or Environment are discussed. Finally, Section 5 summarizes this DELETE) to operate Web resources. paper and presents the outlook for the future. In the RESTFul architecture, workflows are the collections of Web resources. A web resource has three defined attributes: the 2. Methodology URI for resources, the Internet media type of the data supported by the workflow (like XML) and the set of HTTP operations 2.1. System architecture supported by the workflow. After a workflow is deployed as an operable Web resource with a specified URL, users can create, Workflow, or a chain of Web services, has been widely applied modify and delete resources, passing data and information in integrating geospatial Web services (Di, 2005). A virtual work- through different workflow platforms. The main advantages of flow (or abstraction of the workflow) describes abstract Web applying RESTFul architecture in workflow interoperation are Services and data composition and provides ontology information ease of implementation, design and operation.
Load more

Recommended publications
  • Download.Php/10347/Wsbpel- Specification-Draft-120204.Htm, Last Accessed 2004-12-28
    Chapter 1: Security Security-relevance of semantic patterns in cross-organisational business processes using WS-BPEL K.P.Fischer1,2,3, U.Bleimann1, W.Fuhrmann1 and S.M.Furnell2,4 1 Aida Institute of Applied Informatics, University of Applied Sciences Darmstadt, Germany 2 Network Research Group, University of Plymouth, Plymouth, United Kingdom 3 Digamma Communications Consulting GmbH, Darmstadt, Germany 4School of Computer and Information Science, Edith Cowan University, Perth, Australia e-mail: [email protected] Abstract This paper gives an overview of the research project considering security aspects in the context of business process management. In particular, security issues arising when scripts written in the standardized scripting language WS-BPEL (formerly: BPEL4WS or BPEL for short) implementing cross-organisational business processes on top of Web services are deployed across security domain boundaries, are being investigated. It analyses the security- relevant semantics of this scripting language in order to facilitate checking for compliance with security policies effective at the domain of execution. Keywords Security Policy, Policy Enforcement, Cross-Organisational Business Process (CBP), Semantic Analysis, Web Services, Web Services Business Process Execution Language (WS-BPEL, BPEL) 1. Introduction Web services are currently considered a broadly adopted approach for the realization of a service oriented architecture (SOA) used in service oriented computing (SOC) (Curbera et al., 2003; Foster and Tuecke, 2005; Papazoglou and Georgakopoulos 2003). Web services, and the composition or orchestration of them, play a central role in current approaches to service oriented computing (Berardi et al., 2003). Service orientation is also expected to play an important role in grid computing, where the provisioning of computing resources within a conceptual huge network of collaborating computers and devices can also be fostered by services (so called grid services in this context) (Tuecke et al., 2003; ).
    [Show full text]
  • Download.Php/10347/Wsbpel-Specification-Draft-120204.Htm, Last Accessed 2004-12-28
    A Security Infrastructure for Cross-Domain Deployment of Script-Based Business Processes in SOC Environments K.P.Fischer1,3, U. Bleimann1, W. Fuhrmann1, S.M Furnell2,4 1 Aida Institute of Applied Informatics, University of Applied Sciences Darmstadt, Germany 2 Network Research Group, University of Plymouth, Plymouth, United Kingdom 3 Digamma Communications Consulting GmbH, Darmstadt, Germany 4School of Computer and Information Science, Edith Cowan University, Perth, Australia e-mail: [email protected] Abstract This paper addresses security aspects arising in service oriented computing (SOC) when scripts written in a standardized scripting language such as WS-BPEL (formerly: BPEL4WS or BPEL for short), BPML, XPDL, WSCI in order to implement business processes on top of Web services are deployed across security domain boundaries. It proposes an infrastructure and methods for checking the scripts deployed, prior to execution, for compliance with security policies effective at the domain in which a remotely developed script-based business process is to be executed. Keywords Security Policy, Policy Enforcement, Service Oriented Computing (SOC), Service Oriented Architecture (SOA), Business Process Management, Web Services, Web Services Business Process Execution Language (WS-BPEL) 1. Introduction Service oriented computing (SOC) is currently considered one of the most promising new paradigms for distributed computing (Papazoglou and Georgakopoulos, 2003). Though com- paratively new, a significant amount of research has already been dedicated to this area (e.g. Deubler et al. 2004). Web services, and the composition or orchestration of them, play a central role in current approaches to service oriented computing (Berardi et al. 2003). Service orientation is also expected to have an important influence in the area of grid computing, where the provisioning of computing resources within a conceptual huge network of collaborating computers and devices can also be fostered by services (so called grid services in this context) provided by different nodes (Tuecke et al.
    [Show full text]
  • Bpelscript: a Simplified Script Syntax for WS-BPEL
    Institute of Architecture of Application Systems BPELscript: A Simplified Script Syntax for WS-BPEL 2.0 Marc Bischof, Oliver Kopp, Tammo van Lessen, Frank Leymann Institute of Architecture of Application Systems University of Stuttgart Universit¨atsstraße 38, 70569 Stuttgart, Germany http://www.iaas.uni-stuttgart.de in: 35th Euromicro Conference on Software Engineering and Advanced Applications (SEAA 2009). See also BibTEX entry below. BibTEX: @inproceedings {BPELscript, author = {Marc Bischof and Oliver Kopp and Tammo van Lessen and Frank Leymann}, title = {{BPELscript: A Simplified Script Syntax for WS-BPEL 2.0}}, booktitle = {35th Euromicro Conference on Software Engineering and Advanced Applications (SEAA 2009)}, publisher = {IEEE}, year = {2009}, keywords = {service orchestration; service scripting; BPEL; BPM lifecycle}, } © 2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. BPELscript: A Simplified Script Syntax for WS-BPEL 2.0 Marc Bischof, Oliver Kopp, Tammo van Lessen, Frank Leymann Institute of Architecture of Application Systems Universitat¨ Stuttgart Stuttgart, Germany [email protected], [email protected] Abstract—Business processes are usually modeled using graphical notations such as BPMN. As a first step towards execution as workflow, a business process is transformed to an abstract WS-BPEL process. Technical details required for execution are added by an IT expert. While IT experts expect Java-like syntax for programs, WS-BPEL requires processes to be expressed in XML.
    [Show full text]
  • Open Geospatial Consortium, Inc
    Open Geospatial Consortium, Inc. Date: 2009-09-11 Reference number of this document: OGC 09-064r2 Version: 0.3.0 Category: Public Engineering Report Editor(s): Ingo Simonis OGC® OWS-6 Sensor Web Enablement (SWE) Engineering Report Copyright © 2009 Open Geospatial Consortium, Inc. To obtain additional rights of use, visit http://www.opengeospatial.org/legal/. Warning This document is not an OGC Standard. This document is an OGC Public Engineering Report created as a deliverable in an OGC Interoperability Initiative and is not an official position of the OGC membership. It is distributed for review and comment. It is subject to change without notice and may not be referred to as an OGC Standard. Further, any OGC Engineering Report should not be referenced as required or mandatory technology in procurements. Document type: OpenGIS® Public Engineering Report Document subtype: NA Document stage: Approved for Public Release Document language: English OGC 09-064r2 Preface This document summarizes the work done in the SWE thread of OWS-6. Forward Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The Open Geospatial Consortium Inc. shall not be held responsible for identifying any or all such patent rights. Recipients of this document are requested to submit, with their comments, notification of any relevant patent claims or other intellectual property rights of which they may be aware that might be infringed by any implementation of the standard set forth in this document, and to provide supporting documentation. ii Copyright © 2009 Open Geospatial Consortium, Inc.
    [Show full text]
  • Specific Agreement N. 5719.00 Page 1 of 119
    Customer: JRC - Ispra Specific Agreement N. 5719.00 Page 1 of 119 Authors: Matteo Villa, Fabio Status for the invocation of INSPIRE Spatial Data Last update: 20/04/2011 Cattaneo Services TXT e-Solutions S.p.A. Specific Contract 3263 under framework contract DIGIT 06760 STATUS FOR THE INVOCATION OF INSPIRE SPATIAL DATA SERVICES Joint Research Centre – Ispra Date Name Fabio Cattaneo (TXT) Issued by Matteo Villa (TXT) Michel Millot (JRC) 20/04/2011 Lars Bernard, Marek Brylski Distribution list (INSPIRE Network Drafting Team) SPECIFIC CONTRACT No.3263 UNDER F.C. No.DI/06760 Customer: JRC - Ispra Specific Agreement N. 5719.00 Page 2 of 119 Authors: Matteo Villa, Fabio Status for the invocation of INSPIRE Spatial Data Last update: 20/04/2011 Cattaneo Services Table of Contents 1. Executive Summary ........................................................................................................................ 7 2. Introduction ................................................................................................................................... 8 3. Purpose and Scope ......................................................................................................................... 9 4. References and applicable documentations ................................................................................ 10 5. Existing Standards ........................................................................................................................ 11 5.1. Web-services: Overview and concepts .................................................................................
    [Show full text]
  • Security Policy Enforcement in Application Environments Using Distributed Script-Based Control Structures
    University of Plymouth PEARL https://pearl.plymouth.ac.uk 04 University of Plymouth Research Theses 01 Research Theses Main Collection 2007 SECURITY POLICY ENFORCEMENT IN APPLICATION ENVIRONMENTS USING DISTRIBUTED SCRIPT-BASED CONTROL STRUCTURES FISCHER-HELLMANN, KLAUS-PETER http://hdl.handle.net/10026.1/1655 University of Plymouth All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. SECURITY POLICY ENFORCEMENT IN APPLICATION ENVIRONMENTS USING DISTRIBUTED SCRIPT-BASED CONTROL STRUCTURES by KLAUS-PETER FISCHER-HELLMANN A thesis submitted to the University of Plymouth in partial fulfilment for the degree of DOCTOR OF PHILOSOPHY School of Computing, Communications and Electronics Faculty of Technology In collaboration with Darmstadt Node of the NRG Network at University of Applied Sciences Darmstadt September 2007 University of Plymouth Library Abstract Security Policy Enforcement in Application Environments Using Distributed Script-Based Control Structures Klaus-Peter Fischer-Hellmann Dipl.-Math. Business processes involving several partners in different organisations impose deman• ding requirements on procedures for specification, execution and maintenance. A framework referred to as business process management (BPM) has evolved for this pur• pose over the last ten years. Other approaches, such as service-oriented architecture (SOA) or the concept of virtual organisations (VOs), assist in the definition of architec• tures and procedures for modelling and execution of so-called collaborative business processes (CBPs).
    [Show full text]
  • Security-Relevant Semantic Patterns of BPEL in Cross-Organisational Business Processes
    Security-Relevant Semantic Patterns of BPEL in Cross-Organisational Business Processes K.P.Fischer 1,3 , U.Bleimann 1, W.Fuhrmann 1, S.M.Furnell 2,4 1 Aida Institute of Applied Informatics, University of Applied Sciences Darmstadt, Germany 2 Network Research Group, University of Plymouth, Plymouth, United Kingdom 3 Digamma Communications Consulting GmbH, Darmstadt, Germany 4 School of Computer and Information Science, Edith Cowan University, Perth, Australia e-mail: [email protected] Abstract This paper presents results of the analysis of security-relevant semantics of business processes being defined by WS-BPEL (Web Services Business Process Execution Language, BPEL for short) scripts. In particular, security issues arising when such scripts defining cross-organisational business processes on top of Web services are de- ployed across security domain boundaries, give rise to this investigation. The analysis of security-relevant seman- tics of this scripting language will help to overcome these security issues making further exploitation of BPEL as a standard for defining cross-organisational business processes more acceptable. Semantic patterns being combi- nations of particular language features and Web services with specific access restrictions implied by security poli- cies are defined and analysed for this purpose. Applications of the results of this analysis to distributed definition and execution of BPEL-defined business processes may be found in a previous paper of the authors. Keywords Cross-Organisational Business Process (CBP), Web Services Business Process Execution Language (WS-BPEL, BPEL), Semantic Analysis, Security Policy, Web Services, Service Oriented Computing 1. Introduction Web services, and the composition or orchestration of them, play a central role in current ap- proaches to service-oriented computing (Berardi et al., 2003).
    [Show full text]
  • Simulation Software As a Service and Service-Oriented Simulation Experiment
    Georgia State University ScholarWorks @ Georgia State University Computer Science Dissertations Department of Computer Science Summer 7-28-2012 Simulation Software as a Service and Service-Oriented Simulation Experiment Song Guo Computer Sciences Follow this and additional works at: https://scholarworks.gsu.edu/cs_diss Recommended Citation Guo, Song, "Simulation Software as a Service and Service-Oriented Simulation Experiment." Dissertation, Georgia State University, 2012. https://scholarworks.gsu.edu/cs_diss/72 This Dissertation is brought to you for free and open access by the Department of Computer Science at ScholarWorks @ Georgia State University. It has been accepted for inclusion in Computer Science Dissertations by an authorized administrator of ScholarWorks @ Georgia State University. For more information, please contact [email protected]. SIMULATION SOFTWARE AS A SERVICE AND SERVICE-ORIENTED SIMULATION EXPERIMENT by SONG GUO Under the Direction of Xiaolin Hu ABSTRACT Simulation software is being increasingly used in various domains for system analysis and/or behavior prediction. Traditionally, researchers and field experts need to have access to the computers that host the simulation software to do simulation experiments. With recent advances in cloud computing and Software as a Service (SaaS), a new paradigm is emerging where simulation software is used as services that are composed with others and dynamically influence each other for service-oriented simulation experiment on the Internet. The new service-oriented paradigm brings new research challenges in composing multiple simulation services in a meaningful and correct way for simulation experiments. To systematically support simulation software as a service (SimSaaS) and service-oriented simulation experiment, we propose a layered framework that includes five layers: an infrastructure layer, a simulation execution engine layer, a simulation service layer, a simulation experiment layer and finally a graphical user interface layer.
    [Show full text]
  • End-User Service Composition from a Social Networks Analysis Perspective Abderrahmane Maaradji
    End-user service composition from a social networks analysis perspective Abderrahmane Maaradji To cite this version: Abderrahmane Maaradji. End-user service composition from a social networks analysis perspective. Other [cs.OH]. Institut National des Télécommunications, 2011. English. NNT : 2011TELE0028. tel-00762647 HAL Id: tel-00762647 https://tel.archives-ouvertes.fr/tel-00762647 Submitted on 7 Dec 2012 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. R !"#$ $ !" !" # %&' ( ! " !#$#$"% &' ("$ &' ))& ' $&! Abstract Service composition has risen from the need to make information systems more flexible and open. The Service Oriented Architecture has become the reference architecture model for applications carried by the impetus of Internet (Web). In fact, information systems are able to expose interfaces through the Web which has increased the number of available Web services. Moreover, with the emergence of Web 2.0, service composition has evolved toward Web users with limited technical skills. Those end-users, named Y generation, are participating, creating, sharing and commenting content through the Web. This evolution in service composition is translated by the reference paradigm of Mashup and Mashup editors such as Yahoo Pipes! This paradigm has established the service composition within end users com- munity enabling them to meet their own needs, for instance by creating applications that do not exist.
    [Show full text]
  • Web Service Orchestration Driven by Formal Specification
    Web service orchestration driven by formal specification Charif Mahmoudi1, Fabrice Mourlin1 1LACL, Computer Science department, Paris-Est University, 61 avenue du Général de Gaulle, 94010 Créteil Cedex, France, EA 4913 [email protected], [email protected] Abstract. When set of basic web service is built, the next step is to create more complex one. A programmatic approach uses declarative language such as BPEL. This kind of representation is verbose and needs assistance for the creation of business process. We defined a generative strategy leading by formal specification. Because, web service composition languages use standard operators like sequence, choice and parallel; process algebras are right candidate for their design. We use higher order pi calculus for specification of orchestration and consider it as a basis for generating BPEL skeleton. After enrichment of BPEL definition, we interpret it by mobile agents. They play role of a conductor which evaluates a part or a whole BPEL definition. This mobile engine reduces message traffic by replacing message transfer into local message operating. We use mobile agent as distributed conductor of business processes. Keywords: web service, orchestration, composition language, process algebra mobile agent, 1. Introduction Web Services mean many things to many people. Today, a lot of developers have tried to expose web services on their local network. Their first example is often to build a simple web service that generates a response based on information received from the client. But also, it shows how to consume various existing framework web services, including existing services such that computing service (Choleski computation) or geographical service (a map of a next trip in Edinburgh).
    [Show full text]