Components and Services Flashcards Preview

TM354 Last Minute Revision > Components and Services > Flashcards

Flashcards in Components and Services Deck (4):
1

What are the 4 main similarities between services and components?

  1. Well defined interfaces
  2. Loosely coupled
  3. Can be composed
  4. Reusable

2

What are the 6 main differences between services and components?

  1. Components tend to depend on proprietary technologies, whereas services use standard communication protocols
  2. Services are discoverable - they can be found by accessing a repository
  3. Components run on computers controlled by the organisation using them, whereas a service resides on a provider server
  4. Services should be autonomous and independent of other services, so do not have a 'requires' interface
  5. Services can be stateless, meaning they do not retain any memory of previous requests
  6. Clients can often use a service without needing to know its physical location - a service can be moved to a different computer without clients being affected

3

What is a software component?

A software component is a unit of software structured according to the following principles:

  1. A component encapsulates data and operations
  2. A component is fully documented and thoroughly tested
  3. A component's specification clearly separates the component's interface from its implementation
  4. A component's specification may include non-functional characteristics
  5. A component is known to client components only through its interface

4

What is a service?

A service is an abstract description of some unit of business functionality, usually described in terms that are meaningful from both a business and a technical perspective.