Transcript Demystifying SOA and EDA

Demystifying SOA and EDA
Xinke Lin
Andreas Häber
Veena Dodballapur
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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 Forces
• Complexity
• Integration of
Heterogenous
Components
• Number of Interfaces
• Reuse of Code
• Meet Requirements at
low Costs
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Issues 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 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 Architecture
Architectural Elements
• Producers
• Consumers
• Contract
• Service Repository
• Transport
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SOA Characteristics
Discoverable and dynamically bound
 Self-contained and modular
 Interoperability
 Loosely coupled
 Coarse-grained interfaces
 Location-transparent

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SOA 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 - 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 - 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 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 - 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 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 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 - 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 EDA
Attribute
SOA
EDA
Coupling
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
Supports dynamic
asynchronous calls through a
network of modules
execution
path
– response
exchanges
•Request
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 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 System




“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
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• Be scalable
Scenarios 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 – 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)
Laboratory Service
Patient Referral Service
Hospital
Boundary Server
Drug Supplies Service
Service Event Middleware
Service
Discovery
Repository
Pharmaceutical
Company Server
Pharmaceutical Advertising
Service
Insurance
Company Server
Insurance Service
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Architecture Diagram (2 of 2)
Drug Supplies Service
Patient Referral Service
«message»
Request
«event»
Notification
«event»
Notification
Hospital System
«event»
Notification
«event»
Notification
Insurance Service
«event»
Notification
«message»
Request
Laboratory Service
Pharmaceutical Advertising Service
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Conclusions
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Conclusion

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 ??
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