Service Oriented Architecture SOA

1
Service Oriented Architecture - SOA

• A New Paradigm for Developing Enterprise Software
  Systems

2
Outline

• Introduction
• ESB implementation of SOA
• Analysis of ESB implementation
• Conclusion
• References
• Q A

3
Introduction

• Organizations are increasingly collaborating and
  constitutes an enterprise.
• Many organizations have pre-existing IT
  resources.
• Not economical to dispose in favor of mutual
  interaction.
• Must take another approach.
• IBM invents SOA IBM.

4
Introduction

• At the highest level SOA consists of the
  following parts
• A set of service providers.
• A set of service consumers.
• A discovery service.
• Uses XMLbased technologies to achieve platform
  independence.

5
Introduction
6
Introduction

• Service providers makes a registration call to
  the service broker.
• The service broker stores and maintains
  information about service ID and location.
• The Service consumers queries service broker.
• Service broker either
• lets the consumer know about the location of the
  provider or,
• dynamically discovers the provider location and
  lets the consumer know.
• The consumer interacts with provider.

7
Introduction

• Related functionalities are combined into
  cohesive software agents.
• For preexisting software agents a wrapper is
  required.
• Each cohesive software agent can be used as a
  service by the consumers.
• Overall enterprise application is a collection of
  such service providers and consumers.

8
Introduction

• GUEDES describes an application of SOA in a
  distributed data mining application. Please see
  article for more details.
• Because of enterprisewide exposure software
  vulnerabilities are more pronounced in SOA.
• The authors in EPSTEIN mentions some pitfalls
  to be aware of when considering security in SOA
  implementations.

9
Outline

• Introduction
• ESB implementation of SOA
• Analysis of ESB implementation
• Conclusion
• References
• Q A

10
ESB Implementation of SOA

• Two approaches to implement SOA
• Endpointbased approach.
• Busbased approach (ESB).

11
ESB Implementation of SOA

• Endpoint-based implementation

12
ESB Implementation of SOA

• Bus-based implementation

13
ESB Implementation of SOA

• The bus-based implementation central component
  is the service bus called the enterprise service
  bus.
• Can be described using the Publish Subscribe
  style CLEMENTS.

14
ESB Implementation of SOA

• Some ESB features that must be present
  GENENDER
• Standardbased.
• Orchestration.
• Security.
• Reliable.
• Distributed and looselycoupled.
• Incremental adoption.

15
ESB Implementation of SOA

• Two of the commercial implementations are
  available from
• Sonic Software SONIC.
• SUN Microsystems SUN.

16
Outline

• Introduction
• ESB implementation of SOA
• Analysis of ESB implementation
• Conclusion
• References
• Q A

17
Analysis of ESB Implementation

• ESB Implementation is more scalable than the
  endpointbased implementation.

18
Analysis of ESB Implementation

• In endpoint-based implementation

19
Analysis of ESB Implementation

• N software systems.
• Must interact with N1 other systems.
• Therefore requires O(N2) connectors per software
  system.
• To add 1 additional software system we need (N
  N) that is, N2 code points for implementing the
  connectors.
• Similar order of effort is required for removing
  a single software system.
• Becomes extremely tedious and error prone when N
  is large.

20
Analysis of ESB Implementation

• In ESB implementation

21
Analysis of ESB Implementation

• N software systems.
• Requires 2N connectors per software system.
• Therefore requires O(N) connectors and a constant
  for implementing the bus itself.
• To add 1 additional software system we need only
  2N, that is, O(N) number of connectors.
• Similar order of effort is required for removing
  a single software system.
• More scalable than endpointbased approach
  because of linear complexity in adding and/or
  removing software systems.

22
Outline

• Introduction
• ESB implementation of SOA
• Analysis of ESB implementation
• Conclusion
• References
• Q A

23
Conclusion

• Adoption of SOA encourages incremental system
  development for distributed system development.
• Perfectly suitable for developing enterprise
  applications.
• Allows easy migration of organizations to
  enterprise wide systems.
• In particular the busbased approach is better
  and more scalable.

24
Outline

• Introduction
• ESB implementation of SOA
• Analysis of ESB implementation
• Conclusion
• References
• Q A

25
References

• IBM IBM Service Oriented ArchitectureSOA.
  http//www.ibm.com/soa.
• GUEDES D. Guedes, W. Meira Jr., and R.
  Ferreira. Anteater A ServiceOriented
  Architecture for HighPerformance Data Mining.
  IEEE Internet Computing, vol. 10, pp. 3643. IEEE
  Computer Society. JulyAugust 2006.
• EPSTEIN J. Epstein, S. Matsumoto, and G.
  McGraw. Software Security and SOA Danger, Will
  Robinson! IEEE Security and Privacy Magazine,
  vol. 4, pp. 8083. IEEE Computer Society,
  JanuaryFebruary 2006.
• CLEMENTS P. Clements, F. Bachmann, L. Bass, D.
  Garlan, J. Ivers, R. Little, R. Nord, and J.
  Stafford. Documenting Software Architecture
  Views and Beyond. Addison-Wesley Professional,
  Springfield, Massachusetts, 1st edition, 2002.
• GENENDER J. Genender. The Buzz About
  Enterprise Service Bus (ESB). http//www.virtuas.
  com/files/genender20j-f.pdf.
• SONIC Sonic ESB. http//www.sonicsoftware.com/pr
  oducts/sonic_esb/index.ssp.
• SUN SUN Microsystems OpenESB.
  http//java.sun.com/integration/openesb/index.jsp.

26
Outline

• Introduction
• ESB implementation of SOA
• Analysis of ESB implementation
• Conclusion
• References
• Q A

27
Q A