SOA – Service Oriented Architecture

November 2017

The company's information system
generally consists of applications and data constituting its heritage (in English legacy).
With group mergers, changes in technology, this inheritance tends to become heterogeneous
and specialize in business (entity, department, etc.), causing a silo operation, that is to say
a partitioning of the various trades preventing certain forms of cross-masking and the decision maker
an overview of the information system of its business.

The integration of enterprise applications (EAI)
is a solution to this problem. It consists in developing specific connectors for communicating
between them, the different silos of the company.

Service Oriented Architecture

A service-oriented architecture (denoted SOA for Services Oriented Architecture)
is a software architecture based on a set of simple services.

The goal of SOA is to break down a
feature in a set of basic functions, called services, provided by components and describe
Finely the pattern of interaction between these services.

The underlying idea is to stop building the company's life
around applications to ensure to build a comprehensive software architecture
broken down into services corresponding to the company's business processes.

When SOA is based on web services, this is called WSOA, for Web Services Oriented Architecture).

General principles of service-oriented architecture

There is no strictly formal specifications of a
SOA, however, the main unifying concepts
that is found in this architecture are:

  • The concept of service, that is to say a function encapsulated in a component

which can be queried using a query composed of one or more
parameters and providing one or more responses. Ideally
Each service must be independent of the others to ensure
reusability and interoperability.
  • The service description, of describing the parameters

service entrance and the size and type of the returned data.
The main service description format is WSDL (Web Services Description Language), standardized by the W3C.
  • The publication (in English advertising) And discovery (discovery) services. The publication consists of

publish in a book (in English registry or repository) Services available to users, while the notion
Discovery encompasses the ability to search a service among those who
were published. The primary standard is used UDDI
(Universal Description Discovery and Integration), Standardized by the OASIS.
  • Theinvocation, showing the connection and the client's interaction with

service. The main protocol used for invoking services SOAP
(Simple Object Access Protocol).

Benefits of SOA

SOA provides all the benefits
a client-server architecture including:

  • Modularity to easily replace a component (service)

by another
  • A possible reusability of components (as opposed to

an all-in-one tailor made system for an organization).
  • Better opportunities for development (just evolve

a service or add a new service)
  • Greater fault tolerance
  • Easy maintenance

See also

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