RAVNEET K.CHAWLA* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 7, Issue No. 2, 212 - 216
APaaS technology to build workflow-based applications RAVNEET K.CHAWLA COMPUTER SCIENCE AND ENGINEERING DEPARTMENT Thapar University, Patiala-147004, India
Ms. ANJU BALA
T
rich.logic@gmail.com
COMPUTER SCIENCE AND ENGINEERING DEPARTMENT
IJ
A
ES
Thapar University, Patiala-147004, India
ISSN: 2230-7818
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 44
RAVNEET K.CHAWLA* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 7, Issue No. 2, 212 - 216
portable business applications. In this contribution, an attempt is also made to show how workflow modelling is effectively used to deploy a processoriented application. II.BACKGROUND A. Cloud Computing
T
With the promotion of the world’s leading companies, cloud computing has become an area of increasing interest. Cloud computing is a new emerging paradigm for distributed computing that delivers infrastructure, platform, and software (application) as services [2] over the Internet. The features that distinguish cloud from other IT offerings are: elasticity, multi-tenancy, ubiquitous access and pay-per-use [4]. Cloud computing has the ability to provision resources as subscription-based services to share the cloud benefits improving efficiency and utilization [3]. Current examples include Amazon Web Services, Google AppEngine and Microsoft Azure. Thus, Cloud Computing is the sum of SaaS and utility computing [5].
ES
Abstract-Cloud computing is a new benchmark that can effectively facilitate the execution of workflows in business process management system. The workflow technology can effectively manage the business processes satisfying the requirements of modern enterprises. This paper presents how a workflow designed for an interactive processoriented application can be deployed on some of the major cloud infrastructures. The application with its four-tiered architecture is built on REST-style service interface in a visual modelling development environment that itself runs as a cloud application. Keywords: Cloud computing, Workflow, REST, APaaS I. INTRODUCTION
IJ
A
The emergence of new technologies such as cloud computing, REST (Representational State Transfer) and SOA (Service-oriented Architecture) [2] have given a new shape to the design and deployment of process-oriented applications. Every business process follows the concept of workflow technology. Although there exists many workflow management systems, our approach is to model an application using a visual style modelling interface such as OrangeScape Studio [3].Its underlying technology is based on a general purpose APaaS (Application Platform as a service) [1].The application designed using a workflow is deployed as a service on one of the major cloud platforms such as Google AppEngine [3]. The objective is to demonstrate the benefit of using APaaS technology to build
ISSN: 2230-7818
B. Application Platform as a Service Application Platform as a Service (APaaS), an extended application server in the sky is an in-cloud platform. It provides a development toolset for web-based business applications offered as software as a service (SaaS). C. Service Oriented Architecture A service comprises of a software component accessible to the users over a
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 45
RAVNEET K.CHAWLA* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 7, Issue No. 2, 212 - 216
network [6]. Most of the applications are built as web services on the principles of SOA paradigm [2]. A SOA can be implemented through the use of any service based technology, such as SOAP (Simple Object Access Protocol) or REST [2]. Considering these factors, REST-style web services [2] fits well for most of the applications delivered as services on cloud.
A. Data modelling as the start point Data modelling takes care of what data needs to be stored by the application. Instead of representing a technical database design, the data model organizes the data by modelling real world entities. The creation of a data model diagram clearly visualise the entities [3] and their relationships. B. Designing user interface screens
III.ONLINE BANKING APPLICATION
T
The user interface wire-frame links directly to the data model and workflow state. Form designer is a grid based page builder for defining forms and form elements such as display fields and input fields. It includes a point-and-click selector to validate the field elements, specify user permissions and actions [3].
A
ES
Online banking is a service where people can perform financial transactions such as account to account transfers, deposit of cash and withdrawal of cash and so on. In our demo system, the security is provided by giving a Personal Identification Number (PIN) to every customer to access his/her account. The system checks whether the PIN entered by the user is valid or not. It also takes care of the remaining balance in the customer’s account. IV. DESIGNING THE APPLICATION
IJ
Almost all the applications process data into information according to a set of logical rules. A process-oriented application progresses from activity to activity to accomplish a business goal. Orangescape Studio is ideal for designing process-oriented business applications. The platform itself runs as a cloud application. It follows a bottom-up design approach through four perspectivesdata model and rule design (business rules), drag-and-drop form design, graphical process design and action design [3].
ISSN: 2230-7818
C. Workflow modelling A business process is generally visualized using a workflow as a sequence of activities. Workflow is concerned with the automation of procedures where documents, information or tasks are passed between participants according to a defined set of rules. A workflow enables the structuring of applications in a directed acyclic graph form, where each node represents the constituent task and edges represent inter-task dependencies of the applications. In our approach, workflows are designed using a visual modelling environment in the process design perspective. Figure 1 shows the workflow design for our example application.
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 46
T
RAVNEET K.CHAWLA* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 7, Issue No. 2, 212 - 216
D. Defining actions
ES
Figure1: Detailed design of workflow
A
Action designer includes a set of predefined commands such as updating the current entity, creating a loop, searching and calling parent/child entity, sending mail, calling an external web service. The “update” command updates the current model entities, while the “submit” command submits an instance from current workflow activity to the next activity [3].
IJ
V. IMLEMENTATION
The application is successfully implemented through its four-tier architecture comprising of four layers: Presentation layer, Web service layer, Business logic layer and Persistence layer. Figure 2 describes the overall high-level architecture built on SOA foundation. The Presentation layer provides a user interface to access the application [3].
ISSN: 2230-7818
The Web service layer exposes the data model entities as web services. The Business tier architecture provides the Component service exposing the data models as business components. The rule engine embedded in the service interprets the business rules and executes them in run-time configuration. The Workflow Service takes care of activity assignment and automatically moves one instance from one state to another state in the process design. The data model entity and its required attributes persist into RDBMS (SQL, MySQL, Oracle, and DB2).The Persistence service has the capability to feature high scalability and performance in terms of data storage [3].
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 47
RAVNEET K.CHAWLA* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 7, Issue No. 2, 212 - 216
SOA Interfaces-REST or SOAP based
Runtime container REST Service Layer
Business logic Layer
Persistence Layer
Either one of Oracle
NoSql
Figure2: Run-time architecture: Implementation
ES
VI. DEPLOYMENT
VII.CONCLUSION AND FUTURE WORK In this paper, we designed a workflowbased business application supporting REST architecture style. The four-tiered application was designed, developed and deployed in the cloud using a visual modelling environment that itself runs as a cloud application. From the implementation, we conclude that the REST-style Web services can be combined with cloud computing platforms. It can help many enterprises to design and deploy process-oriented applications based on workflow. Some future extensions can also be possible by considering multiple workflows. Applications supporting multiple instances of workflow can also be designed and deployed on some of the cloud infrastructures.
T
Presentation Layer
A
The packaged application can be deployed on one of the cloud platforms such as Google AppEngine, Amazon Web Services and IBM’s Smart Cloud by using a single-click deploy option in- built in the Studio environment. The same application can be hosted on Microsoft .Net and J2EE platforms as on-premise deployment option. Figure 3 shows the options to deploy the application. PUBLI C Cl OUD
C lo ud de p loy m ent
IJ
Go ogle App E ng in e, M icro so ft A zu re
Visu al m ode ling deve lop ment ( 5GL e nvi ronm e nt)
PR I VATE CL OUD
J2 EE J 2J .N E T Com pone nts
E nte rpr ise deplo ym e n t
Figure3: Cloud and Enterprise deployment
Applications can switch between onpremise and enterprise deployments. The current application development approach makes this process a breeze [3].
ISSN: 2230-7818
REFERENCES
[1] D.M.Smith, “Hype Cycle for Cloud Computing, 2010”, white paper, Gartner, July.2010. [2] W.Li and P.Svard, “REST-based SOA Application in the Cloud: A Text Correction Service Case Study”, IEEE 6th World Congress on Services, 2010. [3] https://www.orangescape.com [4] “NIST Definition of Cloud Computing v15,” visited in April 2010. [Online]. Available: http://csrc.nist.gov/groups/SNS/clo ud-computing/ [5] M. Armbrust, A. Fox, R. Griffith, A. D. Joseph, R. H. Katz, A. Konwinski, G. Lee, D. A. Patterson, A. Rabkin, I. Stoica, and et al., “Above the Clouds: A Berkeley View of Cloud Computing”, Feb 2009. [6] P. F. Brown and R. M. B. A. Hamilton, “Reference model for service oriented architecture 1.0,” 2006.
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 48