Re: [service-orientated-architecture] What is SOA?

[Anne Thomas Manes]

I list two fundamental principles:
- service-orientation
- loose coupling

A short excerpt...

Service-orientation:

As implied by the name, the primary SOA design principle is service-orientation.  This principle dictates that if a piece of functionality is required by multiple applications, then the functionality should be refactored and implemented as a shared, reusable service rather than duplicated in each application.

A service, therefore, is a representation of this functionality that can be shared by multiple applications. A service exposes it functionality through a well-defined interface. Service consumers (i.e., applications) use the interface to gain access to the functionality.

 This refactoring concept is relatively simple, but the devil is in the details. Design issues that must be addressed include:

• Interoperability
  
• Reusability
  
• Granualarity
  

[each issue is described in detail]

Loose coupling
Another import SOA design principle is loose coupling. Loose coupling refers to the degree of flexibility that exists between a service consumer and a service provider. Loose coupling enables services to be moved, scaled, managed, and evolved without breaking existing connections.

Loose coupling isn't a single technique. Rather, it refers to a range of interrelated development and deployment techniques, including:

• Decoupled transactions
• Document-oriented messaging
• Clean separation of concerns
• Mediated interactions
  

[each technique is described in detail]


Anne

On 6/29/06, Jan Algermissen <[EMAIL PROTECTED] > wrote:

Hi Anne,

On Jun 29, 2006, at 2:31 PM, Anne Thomas Manes wrote:

> I recently wrote a 36 page document which attempts to define SOA. I
> won't reproduce it here, but here's my introductory paragraph:
>
>
> SOA is a set of design principles for building software systems.

Do you list that set in your paper? Is it available somewhere or can
you share this set of principles here?

Thanks if so.

Jan

> SOA adopts a service-centric approach that is subtly but
> significantly different from previous application-centric
> architectures. At its core, SOA is about factoring functionality
> into shared, reusable services, and applications are built by
> assembling those services into automated business process.
>

> Anne
>
> On 6/29/06, Rama Subba Reddy < [EMAIL PROTECTED]> wrote:
> [Just to soften the shock - you will get as many answers as
> respondents, if not more. If the resulting confusion looks like
> driving you to dementia, just brew yourself a nice cup of
> Darjeeling...
>
> Gervas
> Moderator]
>
> I am a new to this group. Can some one tell me what is
> exactly Service Oriented Architecture?
>
> Thanks in advance..
> Rama
>
>
> __________________________________________________________
> Copy addresses and emails from any email account to Yahoo! Mail -
> quick, easy and free.http://uk.docs.yahoo.com/trueswitch2.html
>
>
>
>
>

__._,_.___

SPONSORED LINKS

Computer software	Computer aided design software	Computer job
Soa	Service-oriented architecture

---

YAHOO! GROUPS LINKS

•  Visit your group "service-orientated-architecture" on the web.
   
•  To unsubscribe from this group, send an email to:
   [EMAIL PROTECTED]
   
•  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

---

__,_._,___