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Xinke Lin

Andreas Häber

Veena Dodballapur

Demystifying SOA and EDADemystifying SOA and EDA

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Overview

Driving forces for new architecture styles Architecture Style, Advantages and Limitations

• SOA

• EDA Comparison and Complementary aspects Fabricated Case Study

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Driving ForcesDriving Forces

• Complexity• Integration of

Heterogenous Components

• Number of Interfaces• Reuse of Code• Meet Requirements at

low Costs

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Issues With Existing SystemsIssues With Existing Systems

Tightly Coupled Too Static Inflexible Not Extensible Not Standardized

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SOA: Service Oriented Architecture

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Service Oriented ArchitectureService Oriented Architecture

Definition

• “The set of components which can be invoked and whose interface definitions can be published and discovered .“ (W3C)

Is it new ? Distributed Computing CORBA

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Service Oriented ArchitectureService Oriented Architecture

Architectural Elements• Producers• Consumers• Contract• Service Repository• Transport

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SOA CharacteristicsSOA Characteristics

Discoverable and dynamically bound Self-contained and modular Interoperability Loosely coupled Coarse-grained interfaces Location-transparent

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SOA In Real WorldSOA In Real World

Web Services• Web services specifies guidelines on how services

interact; that is, it is the tactical implementation of an SOA model most commonly seen in SOAP messages delivered over HTTP.

Examples•Financial Systems – Credit Card Checking•B2B Communication

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SOA - AdvantagesSOA - Advantages

Business Benefits

• Can respond quickly to marketplace changes

• Improves customer service

• Business flexibility IT Benefits

• Gives a more responsive IT organisation

• Decreases development and deployment cycle times

• Reduces maintenance costs

• Enhances existing IT systems

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SOA - LimitationsSOA - Limitations

Team management SOA is good only for interactions of logically

'separate' systems Not a solution for all problems

• Many-Many Communication

• Push Model

• Asynchronous communication

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EDA: Event-Driven Architecture

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Event Driven ArchitectureEvent Driven Architecture

Definition

“The term event driven architecture refers to any application that can detect report and react intelligently to changes in condition.”

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EDA - FeaturesEDA - Features

Individually captures unpredictable, asynchronous events occurring in parallel

Senses real-time events and conditions in business environment/databases

Initiates appropriate response, action, or process Modifies processes in real-time for optimal

response to changing conditions

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Forces Behind EDA DevelopmentForces Behind EDA Development

Business Demand Event Driven Design SOA promotes EDA Vendors offering Enabling Tools Standards Infrastructure and Network technology has

improved a great extent

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EDA - Characteristics

• Publish – Subscribe– Notify Subscribers

selectively• De-coupled

– No Contract– Publisher and Subscriber

have no knowledge – Asynchronous Push

Communication• Many to many

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EDA – Architectural Elements

• Architectural Elements

– Event Receptors

– Event Processors

– Transport

– Event Management Application Program Interfaces

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EDA – Implementation StylesEDA – Implementation Styles

• Simple Event Driven– Simple MOM Middleware

• Event Driven Applications with Integration brokers– Business Process Management

• Complex Event Processing– Business Activity Monitoring

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EDA - Advantages

Maintainability Same Data needs to reach many destinations Integration Reusability Reduced Costs Stakeholder Communication

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EDA - LimitationsEDA - Limitations

Team management Incomplete Standards Testability Inexperience of Architects Not a solution for all problems

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Comparison and complementary aspects of SOA and EDA

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Comparison of SOA and EDAComparison of SOA and EDA

Attribute SOA EDACoupling Loosely coupled Decoupled

Connection One-one Many-Many

Flow Initiation Flow directed by sender

Flow directed by the sink of the recipient

Execution Path •Linear execution path

•Request – response exchanges

Supports dynamic asynchronous calls through a network of modules

Response to Unforeseen Events

•Closed to new unforeseen output once the flow starts

Adaptable to new events

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Why they complement each otherWhy they complement each other

Does not need to be Mutually Exclusive Events invoking Services or Triggered by Services EDA’s being Service Oriented Standard sharing Different use of data

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Enterprise Application Design Trends

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Use cases

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Enterprise Service Bus

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Fabricated Use Case – Medical Fabricated Use Case – Medical SystemSystem

“MRS” is a major referral hospital and offers a comprehensive range of community health services. It has a number of physicians working in different areas.

The hospital is the consumer and provider of services to a number of people, organizations and institutions. One of the challenges the hospital faces is the number of manual processes it has to cope with.

The challenge of the new architecture is to simplify the workflows and eliminate many processes, replacing them with automated applications.

Some Goals• Reduce risk, Accelerate transaction settlement• Provide extensibility and easy integration of existing and new

components• Be scalable

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Scenarios ConsideredScenarios Considered

Requesting services from the laboratory to examine tests.

Referring patients to the hospital. Re-ordering of medicines automatically when they

go out of stock Billing of insurance companies when the patient has

any insurance claims. Providing up-to-date information for doctors in the

hospital about new drugs.

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Services – SolutionServices – Solution

Drug Supplies Services• track of drug information, stock etc

Patient Referring Services• refer a patient to the hospital.

Insurance Services• insurance aspects of the system.

Pharmaceutical Advertising Services• notify subscribers about new drugs

Laboratory Services• clinical and microbiological services

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Architecture Diagram (1 of 2)Architecture Diagram (1 of 2)

Pharmaceutical AdvertisingService

PharmaceuticalCompany Server

Laboratory Service

Drug Supplies Service

Patient Referral ServiceHospitalBoundary Server

Service Event Middleware

Insurance Service

InsuranceCompany Server

ServiceDiscoveryRepository

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Architecture Diagram (2 of 2)Architecture Diagram (2 of 2)

Hospital System

Drug Supplies Service

Insurance Service Laboratory Service

Patient Referral Service

Pharmaceutical Advertising Service

«message»Request

«event»Notification

«event»Notification «event»

Notification

«message»Request

«event»Notification

«event»Notification

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Conclusions

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ConclusionConclusion

Business Processes, their management and design will certainly be benefited by SOA and EDA

Enormous financial and strategic benefits to enterprises obtained by implementing them

EDA and SOA have distinct styles Enterprises will be benefited by looking at them as

complementary architecture styles

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Questions ??