What is SOA "in plain english"? [closed]
Can someone explain in plain english what is SOA all about? I hear SOA here, SOA there but I cannot understand exacly what it is and what is used for. Was it some simple concept and later evolved into something huge or what?
All documents, including wiki are a bit abstract or maybe I'm an idiot and don't get it. Is there an idiot's guide on this?
What exactly is there behind these three letters?
Solution 1:
SOA is a new badge for some very old ideas:
Divide your code into reusable modules.
Encapsulate in a module any design decision that is likely to change.
Design your modules in such a way that they can be combined in different useful ways (sometimes called a "family" or "product line").
These are all bedrock software-development principles, many of them first articulated by David Parnas.
What's new in SOA is
You're doing it on a network.
Modules are communicating by sending messages to each other over the network, rather than by more tradtional programming-language mechanisms like procedure calls. In particular, in a service-oriented architecture the parts generally don't share mutable state (global variables in a traditional program). Or if they do share state, that state is carefully locked up in a database which is itself an agent and which can easily manage multiple concurrent clients.
Solution 2:
You might find this article (What is SOA? - SOA and Web Services Explained ) helpful.
A little teaser:
SOA is a style of architecting applications in such a way that they are composed of discrete software agents that have simple, well defined interfaces and are orchestrated through a loose coupling to perform a required function.
There are 2 roles in SOA- a service provider and a service consumer. A software agent may play both roles. SOA is not an entirely new concept – however, this article mainly focuses on SOA as implemented with web services.
Solution 3:
I see many answers explaining a Service Oriented Architecture (SOA) using even more advanced words and technical terms. I'd like to give a shot at explaining it for the layman, using an analogy in plain english.
But first a description of a SOA
SOA could be described in three layers as seen in the picture below. On one side we have the Provider and on the other side we have the Consumer, separated by a Bridge where the two sides communicate.
The consumer uses a number of Applications necessary for it's business and the provider uses Components that provide these applications with information. They communicate through a set of Services using a common architecture.
The analogy
Imagine a house on the country side, that in many ways is part of a larger community, like a city or town. The city has it's own complex systems for providing water and electricity, handling sanitation, providing transportation and other utilities. The House is the consumer in this model, the City (or community) is the provider and the pipes, sewers, powerlines, optical fibers etc. is the Infrastructure in which they communicate.
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, underfloor 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.
I hope this gave at least someone a better picture of a SOA.