Service Development Methodologies In SOA
Broadly service development methodologies are categorized in to two types.
1)Wrapping legacy functionality
2)Green field development
Wrapping legacy functionality:
To meet the changing business requirements,the existing business functionality in the legacy systems(ex:-Mainframes) needs to be re-used as far as possible.One of the approaches to implement this is to wrapp Legacy business functionality as service and expose to service consumers.Legacy business functionality can be exposed as service through the use of adaptors which will enable to connect to the legacy applications and access the business functionality through native API’s.EAI tools comes with application specific adaptors which can be used to access the business functionality and uses webservice adaptors to expose these functionalities as services.
Green field development:
1)Wrapping legacy functionality
2)Green field development
Wrapping legacy functionality:
To meet the changing business requirements,the existing business functionality in the legacy systems(ex:-Mainframes) needs to be re-used as far as possible.One of the approaches to implement this is to wrapp Legacy business functionality as service and expose to service consumers.Legacy business functionality can be exposed as service through the use of adaptors which will enable to connect to the legacy applications and access the business functionality through native API’s.EAI tools comes with application specific adaptors which can be used to access the business functionality and uses webservice adaptors to expose these functionalities as services.
Green field development:
In the green field development methodology services are developed from scratch.Service consumer,Service provider & Service Mediator forms the core part of service development.A service requires an interface(ex:-WSDL) through which it can be exposed to the service consumers.A service interface contains the operations,method signature, binding information etc.Service requests from a service consumer to a service provider happens through a service mediator.Service mediator(ex:-ESB) could be used to receive,transform&route messages from service consumers to service providers.Service provider implements the service and publishes the corresponding WSDL to a registry(ex:-UDDI).Service consumer make a look up in the registry and searches for a particular service and invokes the service through a service mediator. Communication between various participants can be acheived by using various communication protocols ex:-soap/http,soap/https,soap/jms etc.There are many traditional EAI tools in the market which provides out-of-box functionality to build services and technologies like J2EE,.NET to build new custom services.
