1. SOA (Service Oriented Architecture)
Evolution of Architecture.
What is SOA?
SOA Concepts
Evolution of SOA
Why SOA?
SOA – Real World Application
Benefits of SOA

2. Evolution of Architecture

3. Evolution of Architecture (Contd..)
Monolithic: Processing, data and the user interface all reside on the same system
Client/Server: Architecture which separates a client from a server, and business is almost always implemented over a computer network
3-Tier/N-Tier: Architecture in which the user interface, business logic, computer data storage and data access are developed and maintained as independent platforms
Components and Objects (EAI): Architecture which is built as components and modular logical units with communication done through an integration mechanism
Services: Architecture that leverages open standards to represent software assets as services with a focus on application assembly

4. What is SOA? Service Oriented Architecture
Flexible method of structuring and managing component-based systems
Architectural approach to define integration architectures based on the concept of a service. Applications collaborate by invoking each others services and services can be composed into larger sequences to implement business processes.
Information technology architecture that enables distributed computing environment with many different types of computing platforms and applications
Supports a business driven approach to architecture development in line with current business needs rather than a technology based approach
Services in an SOA are:
Loosely-coupled
Used to compose multiple applications
Discovered and invoked dynamically
May feature standard interfaces or a common format

5. Key terms in SOA Service Service Consumer Service Producer Message
Reusable piece of functionality
Service Consumer
Client/Application which invokes the functionality
Service Producer
Client/Application which provides the functionality
Message
Information served/invoked
Dynamic Discovery
Registry
Web Service

6. Key terms in SOA Service encapsulate reusable business functions
are defined by explicit, implementation-independent interfaces
are invoked through communication protocols that stress location transparency and interoperability.
can be dynamically located and invoked  Directory Service available

7. Key terms in SOA Message
Mode of communication between service consumer and service provider
Typically constructed using XML documents that conforms to defined XML schema (WSDL)
Dynamic Discovery
Directory services to list the services where service consumers can query for service details and contact service provider
Advantages of dynamic discovery:
Scalability – Services can be added incrementally
Consumer and provider decoupling
Allows implementation updates
Can chose provider at run time rather than hard coding

8. SOA and Web Services
Web Services are a specialized implementation of Services.
Web services play major enabling role in SOA
Web services are built on top of well-known and platform-independent protocols.
HTTP  Interoperability
XML  Platform independent interface contract
UDDI
WSDL  Dynamic Discovery and Invocation
SOAP  Standard Messaging

9. SOA Concepts in the Real World - Cable
A cable TV company (a service provider)
has the capacity (the underlying capability)
to collect and distribute content (services)
Wiring from the cable TV company makes a distribution grid (the service bus)
to supply the content (the services)
The distributed TV signal (the service)
Is available for the typical usage in a residential consumer’s house (service consumer)

10. SOA Concepts by connecting a device to an outlet (service interface)
A consumer accesses a program
by connecting a device to an outlet (service interface)
Service delivery (service invocation) occurs when a device is connected to the interface.

11. Cable TV Model
Service Provider
Service Bus
Consumer
Interface

12. SOA Concepts
The consumer can connect different devices (TV, VCR, DVR, etc.) to the interface;
The provider is not concerned with how the service is used.
The provider can send different types services (satellite signal, broadcast signal, DVD, etc);
The consumer is not concerned with the service’s source.
Therefore … the end points are said to be Loosely Coupled.
The service provider creates a list of available services (shows available).
Also provided any information needed to use the service is (time, channel, duration, etc.)
Service consumers can browse the list to determine what service they want to consume.
This is the Registry
The Service Provider and the Service Consumer have a agreement or contract (Service Level Agreement) which sets the monthly fee for a specified number of available channels.

13. Evolution of SOA Service-Based Integration
Heterogeneous systems sharing data and functionality using a standard message format
Legacy Systems “wrapped” by a service
SOAP/HTTP
Service Consumers
Service Consumers
Service Providers
SOAP/HTTP
SOAP/MQ
Service
Consumers
Service
Providers
Legacy
Systems

14. Why SOA? DISADVANTAGES of TRADITIONAL APPROACHES Tight Coupling
Distributed and soiled applications
Integration Nightmare
Distributed platforms
Varying Protocols
Varying Devices
Application/functionality Redundancy
Application centric and not business centric
Why SOA?
Loosely Coupled
Every Application able to communicate seamlessly
No P2P (Point-to-Point) integration (API based).
Based on open standards with wide support from industry
“Retain and reuse” rather than “rip and replace”
Paradigm Shift
With SOA, businesses can use existing assets to accommodate changed business requirements and be flexible to adapt

15. SOA – Real World application
Client Profile: Leading Credit Card Company
Business Issue:
Member banks had to process cardholder disputes via a paper system.
Automating the process was difficult because the banks had incompatible back-end and legacy systems.
How SOA Helped:
SOA allows direct communication between member banks and the back-end systems, simplifying transaction research, dispute case search and retrieval, and requests for copies of original paper receipts.
Savings are said to total $52 million a year in direct operating costs and $300 million in ancillary savings.
What's more, new projects have been able to reuse services from this project, helping to reduce development time and risk

16. SOA – Layered Architecture
Object Oriented technology can be used to implement Components.
Services can be used to access components

17. Main SOA Standards Policy
Set of conditions or rules under which service provider makes service available to consumers
Security
Identification, authorization and access control
Transaction
Conditions applicable for a group of services to deliver consistent result
Management
Administration of services

18. SOA Standards Transport Mechanism used to move service requests
Service Communication Protocol
Agreed mechanism for communication
Service Description
Agreed schema for service description, invocation mechanism and input/output data
Service
Reusable Business process
Business Process
Collection of services, invoked in a particular sequence with a particular set of rules, to meet a business requirement. Business process could be considered a service in its own right.
Service Registry
Repository of service and data descriptions

19. Benefits of SOA
Leverage Existing Assets and ability to integrate with future assets
Easier to integrate and manage complexity
Measurable business value: increased business agility and flexibility, and faster time-to-market and time-to-value
Reduce IT development cost and increase reuse
Reduced complex integration and maintenance costs (integration is typically one of the larger headaches for IT departments)
Integrate disparate IT systems so they can communicate with each other, reducing the need for multiple systems that do different things in isolation
Extend the life of their current IT assets, while still adding needed functionality
Create an expandable IT architecture that meets current business needs, while ensuring long-term expandability and flexibility to meet future business needs as they arise

20. SOA is not a One-stop Solution
SOA : Business Centric
SOA is not a One-stop Solution