1. SO-Architectural Roadmap
B. Ramamurthy
6/19/2019

2. Review In Chapter 4 we discussed In this llecture we will discuss
Definitions of SOA by experts in the field
Our own simple definition of an SOA
types of services
In this llecture we will discuss
Details of the various types of services
Architecting an SOA (stages)
Entry points to SOA design
Chapters 5 and 6
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3. Basic / horizontal Services
Fundamental services
Maintain no conversational state
Data-centric services:
Encapsulates business data
purpose of data centric services is to handle persistent data typically stored in an Enterprise Information System (EIS).
An EIS could be a simple data base or integrated data base from several sources.
A file system relational data base or a object relational mapping, data access objects and layering: all these fall under this category.
For example, “store” operation from a user web service could invoke a data-centric service that stores the data in the “resource” defined in the operational environment.
What is a resource in this context?
A data stream, relational DB data source, a data queue
A “store” on a business object (BO) may results many physical writes to (one or more distributed) data bases. Data-centric service takes care of this.
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4. Horizontal services Logic centric services
Encapsulate algorithms for complex calculations or business rules.
Consider the example of Insurance Product Engine (fig.5.3) (For example: Geico or Progressive Insurance)
We will discuss three alternative approaches to providing this function and why services-based one is advantageous. (pp.72-74)
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5. Insurance Product Engine
Call center
Web site 1
Claims
Agency 1
Contract
Administration
Agency 2
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6. Intermediary Services
Stateless services that bridge the technological inconsistencies and design gaps in an architecture.
Gateways, adapters, facades, and functionality adding services
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7. Technology gateway service
Frontend Service
Technology A
Technology A
Tech Gateway
Technology B
Technology B
Basic Service
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8. Façade Intermediary Service
Application 1
Application 2
Application 3
Facade
Basic service 1
Basic service 2
Basic service 3
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9. Process centric services
Process centric services can encapsulate the knowledge of the organization’s business processes.
Stateful: they contain and maintain state
These are project-specific
Requires careful design satisfying the domain rules and business policies
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10. Process-centric service (contd.)
Application Frontend
Process-centric service
service 1
service 2
service 3
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11. Process-centric service (contd.)
Application Frontend
service 1
service 2
service 3
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12. Enterprise level services
Security
Accounting
Billing
SLAs (service level agreements), service metering
We will refer to these as horizontal services, i.e., common domain-independent utility services
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13. Enterprise Services layers (fig.5.9, 5.10)
Enterprise layer
Process layer
Intermediary layer
Basic layer
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14. The architectural roadmap: The stages in development
Fundamental SOA
Design fundamental services
Networked SOA
Add intermediary services
Process-enabled SOA
Add process-centric services, front-ends
These three stages reach maturity at different rates, services gain more responsibility as the system matures.
Advantages of using service-orientation will be apparent as the stages evolve independently of each other
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15. Fundamental SOA
Excellent starting point for introduction SOA in an organization
A fundamental SOA consists of two layers:
Enterprise layer that consists of front-ends, and
The basic layers that consists of basic services
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16. Airline Enterprise Enterprise Layer Basic layer Airline Web site
Billing
Flight
Booking
Customer
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17. Expanded Airline Enterprise
Enterprise Layer
Airline
Web site
Billing
Application
Basic layer
Billing
Flight
Booking
Customer
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18. Fundamental SOA: Summary
Based on which future expansion can take place
Simple to implement
Complex front-end
Increased maintainability
Shared services can make data replication largely obsolete
Good starting point/entry point to SOA
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19. Networked SOA
It deals with backend complexity in addition to technical and conceptual integration.
If offers flexibility in integrating software assets of an enterprise.
Enables loose coupling
Addition of intermediary layer with services that handle
distributed transactions, (fig.6.6)
bridge technology gaps, (fig 6.7)
database integration, (fig 6.9)
Add new functionality, (fig 6.10)
Wrap legacy applications/service (fig.6.10)
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20. Networked SOA Enterprise Layer Intermediary layer Basic layer Airline
Web site
Intermediary layer
BookAndBill
Basic layer
Flight
Customer
Booking
Billing
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21. Process-enabled SOA
The key feature is the maintenance of a process state in process-centric services.
Stateful services (server-side state)
Encapsulates complexity of processes (Ex: runExperiment in a complex scientific lab experiment)
Possibility of sharing states between clients (Ex: research whiteboard)
Handling long-living processes (Ex: auction framework)
Enables the IT and business alignment
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22. Process-enabled SOA Enterprise Layer Business Layer Intermediary layer
Airline
Web site
Business Layer
BookingProcess
Intermediary layer
BookAndBill
Basic layer
Flight
Customer
Booking
Billing
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23. Process-enabled SOA (contd.)
Enterprise Layer
Airline
Web site
Business Layer
B2B process
mobileprocess
BookingProcess
Intermediary layer
BookAndBill
Basic layer
Flight
Customer
Booking
Billing
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24. Process-enabled SOA (contd.)
Enterprise Layer
Airline
Web site
Business Layer
cancellation process
Mobile
process
BookingProcess
Basic layer
& SMS
Flight
Booking
Billing
Waitlisting
Customer
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25. Process-enabled SOA summary
Enables light-weight frontends (handles only user interaction)
Encapsulates complexities of business processes
Abstracts complexities of backend systems
Enables separation of business logic from technology complexities
Is required for integration of independent organizations and implementation of complex processes
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26. Enterprise Services layers (fig.5.9, 5.10)
Enterprise layer
Process layer
Intermediary layer
Basic layer
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27. Airline Enterprise Enterprise Layer Basic layer Airline Web site
Billing
Flight
Booking
Customer
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28. Expanded Airline Enterprise
Enterprise Layer
Airline
Web site
Billing
Application
Basic layer
Billing
Flight
Booking
Customer
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29. Networked SOA Enterprise Layer Intermediary layer Basic layer Airline
Web site
Intermediary layer
BookAndBill
Basic layer
Flight
Customer
Booking
Billing
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30. Process-enabled SOA Enterprise Layer Business Layer Intermediary layer
Airline
Web site
Business Layer
BookingProcess
Intermediary layer
BookAndBill
Basic layer
Flight
Customer
Booking
Billing
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31. Process-enabled SOA (contd.)
Enterprise Layer
Airline
Web site
Business Layer
B2B process
mobileprocess
BookingProcess
Intermediary layer
BookAndBill
Basic layer
Flight
Customer
Booking
Billing
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32. Process-enabled SOA (contd.)
Enterprise Layer
Airline
Web site
Business Layer
cancellation process
Mobile
process
BookingProcess
Basic layer
& SMS
Flight
Booking
Billing
Waitlisting
Customer
6/19/2019