5.IJAEST Vol No 7 Issue No 2 APaaS Technology to Build Workflow Based Applications 212 216

8/6/2019 5.IJAEST Vol No 7 Issue No 2 APaaS Technology to Build Workflow Based Applications 212 216

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APaaS technology to build

workflow-based applicationsRAVNEET K.CHAWLA

COMPUTER SCIENCE AND ENGINEERING DEPARTMENT

Thapar University, Patiala-147004, India

[email protected]

Ms. ANJU BALA

COMPUTER SCIENCE AND ENGINEERING DEPARTMENT

Thapar University, Patiala-147004, India

RAVNEET K.CHAWLA* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIESVol No. 7, Issue No. 2, 212 - 216

ISSN: 2230-7818 @ 2011 http://www.ijaest.iserp.org. All rights Reserved. Page 44


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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 process-

oriented application can be deployed on

some of the major cloud infrastructures.

The application with its four-tiered

architecture is built on REST-style serviceinterface in a visual modelling

development environment that itself runs

as a cloud application.

Keywords: Cloud computing, Workflow,

REST, APaaS

I. INTRODUCTION

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 anapplication 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 thebenefit of using APaaS technology to build

portable business applications. In this

contribution, an attempt is also made to

show how workflow modelling is

effectively used to deploy a process-

oriented application.

II.BACKGROUND

A. Cloud Computing

With the promotion of the worlds

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-basedservices 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].

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




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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, suchas 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.

III.ONLINE BANKING APPLICATION

Online banking is a service where people

can perform financial transactions such asaccount 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 customers

account.

IV. DESIGNING THE APPLICATION

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 perspectives-

data model and rule design (business

rules), drag-and-drop form design,

graphical process design and action design

[3].

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

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].

C. Workflow modelling

A business process is generally

visualized using a workflow as asequence 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 andedges 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.




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Figure1: Detailed design of workflow

D. Defining actions

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].

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].

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 ruleengine 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].




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Figure2: Run-time architecture: Implementation

VI. DEPLOYMENT

The packaged application can be deployed

on one of the cloud platforms such as

Google AppEngine, Amazon Web

Services and IBMs 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 J2EEplatforms as on-premise deployment

option.

Figure 3 shows the options to deploy the

application.

Figure3: Cloud and Enterprise deployment

Applications can switch between on-

premise and enterprise deployments. The

current application development approach

makes this process a breeze [3].

VII.CONCLUSION AND FUTURE

WORK

In this paper, we designed a workflow-

based business application supportingREST architecture style. The four-tiered

application was designed, developed anddeployed 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 canhelp many enterprises to design and deploy

process-oriented applications based onworkflow.

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.

REFERENCES

[1]D.M.Smith, Hype Cycle for CloudComputing, 2010, white paper,

Gartner, July.2010.[2]W.Li and P.Svard, REST-based

SOA Application in the Cloud: AText Correction Service Case

Study, IEEE 6th

World Congresson 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.

REST Service Layer

Persistence Layer

Presentation Layer

Business logic Layer

SOA Interfaces-REST or SOAP based

Runtime

container

Oracle NoSql

Either one of

J2J

Google AppEngine,

Microsoft Azure

J2EE .NET

Components

Cloud deployment

Enterprise deployment

Visual modeling development

( 5GL environment)

PUBLIC ClOUD

PRIVATE CLOUD



5.IJAEST Vol No 7 Issue No 2 APaaS Technology to Build Workflow Based Applications 212 216

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