Define and explain the following central design tasks: components, connectors and configuration

Component and Connector

• These are the two main elements of C&C architectural view of a system .

• C&C view describes a runtime structure of the system.

• It shows what components exist when the system is executing and how they interact during the execution.

Component

• Software architecture describes how a system is structured into components and connectors.

• Programming Languages are not able to express architecture/structure of any software.

• Programming Languges only express implementation or code of software.

• A Software component is a smallest building block of software architecture.

• It is an architectural entity that encapsulates a subset of the system's functionality and/or data, with an interface specifying the services it provides and request.

• Components are usually computational elements or data stores that have some presence during the system execution.

• It is a unit of deployment and it can be deployed independently.

• It is a unit of reuse.

• Components can be small (one object) or large (a library of objects or a complete application).

• Components provide application specific functionality.

Examples:-

Client,Server,Database etc.

Connectors

• For composing a system from its components, it is neccessary that these components interact with each other for information exchange.

• So a connector is a building block that enables interaction among components.

• Connectors define the means of interaction between these components.

• Connector may provide communication between multiple components.

• A component may interact with another using any of the following connectors :-

  Event, Client/Server middleware, Messages, Shared variables, Remote Procedures Call,TCP/IP ports, HTTP etc.

SOFTWARE CONFIGURATION MANAGEMENT

• Software configuration is the state of all project deliverables at any point of time.

• Software configuration management deals with effectively tracking and controlling the configuration of a software during its life cycle.

Activities

1. Configuration Identification

Controllable objects:

1. Requirement specification document

2. Design document

3. Tools such as compiler

4. Source code

5. Test cases

6. Configuration Identification

Configuration management plan is written during the project planning phase.

2. Configuration Control

• Configuration control is the process of managing changes fó controlled objects.

• Configuration control allows only authorized changes to the controlled objects to occur and prevents unauthorized changes.

Configuration management tool

• Developer first makes a reserve request. After the reserve command successfully executes, a private copy of the module is créațed in developers local directory.

• Developer carries out all necessary changes on his private copy.

• The changes need to be restored in configuration management repository.

• Restoring requires the permission of a change control board (CCB).

• CCB reviews the changes made to the controlled object.