PRINCIPLES OF SERVICE ORIENTATION

Transcription

1 PRINCIPLES OF SERVICE ORIENTATION

2 Service Orientation and the enterprise 2 / 20 Enterprise Logic Business logic - documented implementation of the business requirements Application logic - automated implementation of business logic organized into various technology solutions The service interface layer positions services to represent business logic and abstract application logic

3 Anatomy of a SOA Logical components of the Web Services Framework 3 / 20

4 Anatomy of a SOA Logical components of the Automation Logic 4 / 20 Fundamental Parts Messages = units of communication Operations = units of work Services = units of processing logic Processes = units of automation logic

5 5 / 20 The purpose of these views is to express the process, services and operations. Provides a flexible means of partitioning and modularizing the logic.

6 Anatomy of a SOA Components of SOA 6 / 20 Message - data required to complete some or all parts of a unit of work. Operation - the logic required to process messages in order to complete a unit of work.

7 7 / 20 Service - a logically grouped set of operations capable of performing related units of work. Processes - contains the business rules that determine which service operations are used to complete a unit of automation.

8 Anatomy of a SOA How Components in an SOA inter-relate 8 / 20

9 Common Principles of Service Orientation 9 / 20

10 10 / 20 Common Principles of Service Orientation 1. Reusable Encourages reuse in all services

11 11 / 20 Common Principles of Service Orientation 2. Share a formal contract Service contracts provide a formal definition of: The service endpoint Each service operation Every input and output message supported by each operation Rules and characteristics of the service and its operations Contracts need to be carefully maintained and versioned after their initial release.

12 Common Principles of Service Orientation 3. Loosely Coupled 12 / 20 A service acquires knowledge of another service while still remaining independent of that service Achieved through the use of service contracts

13 13 / 20 Common Principles of Service Orientation 4. Abstract Underlying Logic Acts like black box - what is exposed via the service contract is only visible

14 14 / 20 Common Principles of Service Orientation 5. Composable Ensure that services are designed so that they can participate as effective members of other service compositions if ever required.

15 Common Principles of Service Orientation 6. Autonomous 15 / 20 Services exercise a high level of control over their underlying runtime execution environment. Represents the ability of a service to carry out its logic independently of outside influences It only knows it at the run time Service Level Autonomy Service independent but share resources Pure Autonomy The underlying logic is under complete control and ownership of the service

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17 Common Principles of Service Orientation 7. Stateless 17 / 20 State Information Data specific to current activity Services Minimise the amount of state information Promotes reusability and Scalability

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19 Common Principles of Service Orientation 8. Discoverable 19 / 20 Avoid accidental creation of redundant service. The service should allow their description to be searched and understood by humans.

20 End THANK YOU