Sunday, 24 February 2008

Business rules and soa

Soa service API ideal for common services like exchange money.
Service could become industry standard and money houses provide
implementations in their various languages.

Qos elements security, reliable messaging.

Component based philosophy is bring oo concepts to component level,
soa brings these loosely coupled components together.

The components can be built in a layered architecture too so all
bussiness util comes sit in same layer ie address book service can
then be reused by other layers.

Saturday, 23 February 2008

Esoteric, predicates and declarative language

Esoteric - bunch of info only known by select few

Predicates - statements that are true or false

Declarative language the outcome is same whatever order of execution

Nomenclature - proper name

Sent from my iPhone

Sunday, 17 February 2008


SCA defines a mechanism for defining components and how they work with each other.

SCA is language agnostic.

SCA does define its own programming model but you can use other programming models like BPEL or Spring framework for example within a component.

SCA defines common assembly model.



Mojo is a maven plugin.

Historically, MOJO is a play on POJO (Plain-old-Java-object), substituting "Maven" for "Plain". Mojo is also an iteresting word (see definition ). From Wikipedia , a "mojo" is defined as: "...a small bag worn by a person under the clothes (also known as a mojo hand). Such bags were thought to have supernatural powers, such as protecting from evil, bringing good luck, etc."

SOA Design Points

It is good from a design perspective to separate out api from implementation.

SOA and service-orientation are implementation-agnostic paradigms that can be realized with any suitable technology.

Loose coupling - Services maintain a relationship that minimizes dependencies and only require tat they retain an awareness of each other.

Service contract - Services adhere to a communications agreement, a defined collectively by one or more service descriptions and related documents.

Autonomy - Services have control over the logic they encapsulate.

Abstraction - Beyond what is described in the service contract, services hide logic from the outside world

Reusability - Logic is divided into services with the intention of promoting resuse.

Composability - Collections of services can be coordinated and assembled to form composite services.

Statelessness = Services minimize retaining information specific to an entity.

Discoverability - Services are designed to be outwardly descriptive so that they can be found and assessed via available discovery mechanisms.


Services understand each other through use of service descriptions (ie. wsdl) A service description has a name and location of service. The manner in which services use service descriptions results in a relationship classified as loose coupling.


SOA is a term that represents a model in which automation logic is decomposed into smaller, distinct unit of logic. Collectively, these units comprise a larger piece of business automation logic. Individually, these units can be distributed. (Note: City scenario, lots of businesses some offer same services etc.. but agree on common language, common currency..)


The concern addressed by a service can be small or large


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