1. Service-oriented architecture
8th July 2013

2. What is a Service?
• A service is a reusable component that can be used as a building block to form
larger, more complex business-application functionality.
• A service may be as simple as “get me some person data,” or as complex as
“process a disbursement.”
• How the service is implemented, and how a user of the service accesses it, are
limited only by the SOA infrastructure choices of the enterprise.
• From a theory point of view, it really doesn’t matter how a service is implemented.
• Service-Oriented Architecture (SOA) is an architectural style. Applications built
using an SOA style deliver functionality as services that can be used or reused
when building applications or integrating within the enterprise or trading partners.

3. Analogy
• This model could loosely be
compared to a SOA. The people in
the house uses a number of
different "applications" like
radiators, computers, toilets,
lamps, under floor heating,
bathtubs etc. These applications
don't care how the city generates
the water, creates the electricity
or handles the waste as long as it
works. The components of the
city are generators, water pumps
and sanitation areas. It provides
the house with all these needs
but it's up to the house to use it in
what ever way it sees fit

4. A real world example(cooks)
• Let's assume you have 4 cooks. In SOA, you assume they
hate each other, so you strive to let them have to talk to
each other as little as possible.
• How do you do that? Well, you will first define the roles
and interface -- cook 1 will make salad, cook 2 will make
soup, cook 3 will make the steak, etc.. Then you will place
the dishes well organized on the table (so these are the
interfaces) and say, "Everybody please place your creation
into your assigned dishes. Don't care about anybody else.".
• This way, the four cooks have to talk to each other as little
as possible, which is very good in software development --
not necessarily because they hate each other, but for other
reasons like physical location, efficiency in making decisions
etc.

5. Revolutionary steps
• programmers learnt that organizing code into modules made it easy to
maintain and reuse This led to the development of large libraries of code
that are still used today
• The next major revolution in software design was object orientation. The
implementation details of an object were hidden from the consumers of
the object and could be changed as long as the object’s signature
remained the same. This led to even greater ease of maintenance and
extensibility. where objects could reside on different machines across a
network and talk to each other using various remote access protocols .
• The industry gradually realized that there was a huge potential market for
pieces of functionality that could be plugged into software applications
and customized for that specific application’s needs. This led to the
concept of software components.
• The latest buzzword in the software industry is ‘Service Orientation’. In
this approach, software functionality is defined as a set of services. Service
Oriented Architecture (SOA) Explained

6. SOA is an evolutionary step
 for architecture

7. Motivation
• Applicatio
n Centric
• Goal -
Service
Centric
• Service
Centric

8. Before SOA – After SOA
source:IBM

9. SOA is acronym for Service Oriented
Architecture.
• SOA is designing and writing software applications in such a way that distinct
software modules can be integrated seamlessly with high degree of re-
usability.
• Most of the people restrict SOA as writing client/server software-web-
services. But it is too small context of SOA. SOA is much larger than that and
over the past few years web-services have been primary medium of
communication which is probably the reason why people think of SOA as web-
services in general restricting the boundaries and meaning of SOA.
• You can think of writing a database-access module which is so independent
that it can work on its own without any dependencies. This module can
expose classes which can be used by any host-software that needs database
access. There's no start-up configuration in host-application. Whatever is
needed or required is communicated through classes exposes by database-
access module. We can call these classes as services and consider the module
as service-enabled.

10. What is Service Architecture?
• A collection of services
• classified into types
• arranged into layers
• Governed by architectural
patterns and policies
services
type typetype
source:TietoEnator AB, Kurts
Bilder

11. Benefits of Service Oriented
Architecture (SOA):
• 1. Platform Independence –
• 2. Focused Developer Roles –
• 3. Location Transparency –
• 4.Code Reuse _
• 5. Greater Testability
• 6. Parallel Development –
• 7. Better scalability –
• 8. Higher availability –.

12. What is an Enterprise Service Bus
An enterprise service bus is an
infrastructure used for building compound
applications
• is the glue that holds the compound application together
• is an emerging style for integrating enterprise applications in an
implementation-independent fashion
• can be thought of as an abstraction layer on top of an Enterprise
Messaging System
• is an infrastructure used for building compound applications
• is the glue that holds the compound application together
• is an emerging style for integrating enterprise applications in an
implementation-independent fashion
• can be thought of as an abstraction layer on top of an Enterprise
Messaging System

13. Characteristics of
ESB
• Key Characteristics of an ESB
• Streamlines development
• Supports multiple binding
strategies
• Performs data transformation
• Intelligent routing
• Real time monitoring
• Exception handling
• Service security

14. SOA Principles
• Standardized Service Contracts
• Loose Coupling
• Abstraction
• Reusability
• Autonomy
• Statelessness
• Discoverability
• Composability

15. SOA Depends on who you are!
Business owner: is a solution to increase your incomes
and business .
Enterprise architect: is a way to draw nice and clean
piece of software on a blank canvas.
Architect: is the solution to design loosely coupled services
over an integration platform, to just plug services into outlets.
Developer: is a programming paradigm where a service is in
the center of the design and the code.

16. SOA Depends on who you are!
Business owner: is a solution to increase your incomes
and business .
Enterprise architect: is a way to draw nice and clean
piece of software on a blank canvas.
Architect: is the solution to design loosely coupled services
over an integration platform, to just plug services into outlets.
Developer: is a programming paradigm where a service is in
the center of the design and the code.

17. SOA Depends on who you are!
Business owner: is a solution to increase your incomes
and business .
Enterprise architect: is a way to draw nice and clean
piece of software on a blank canvas.
Architect: is the solution to design loosely coupled services
over an integration platform, to just plug services into outlets.
Developer: is a programming paradigm where a service is in
the center of the design and the code.