Software MEIC. (Lesson 4)

Transcription

1 Software MEIC (Lesson 4)!

2 Last class The Architecture Influence Cycle The AIC applied to Fénix

3 Today Revisiting the definition of Software Architecture How to describe a Software Architecture

4 What is Software Architecture?

5 The definition of software architecture is

6 The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them.

7 The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them.

8 The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them.

9 Structure(s)?

10 1. Something arranged in a definite pattern of organization.! -- Merriam-webster online

11 2. The arrangement of particles or parts in a substance or body.! -- Merriam-webster online

12 3. Coherent form or organization.! -- Merriam-webster online

13 4. The aggregate of elements of an entity in their relationships to each other.! -- Merriam-webster online

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17 The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them.

18 The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them.

19 Object Class Task Process Library Framework What are software elements? Module Database Package Thread Component Communication channel

20 Object Class Task Process Library Framework What are software elements? Module Database Package Thread Component Communication channel

21 Object Class Task Process Library Framework What are software elements? Module Database Package Thread Component Communication channel

22 Browser Web server DB

23 Presentation logic Domain logic Data access

24 The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them.

25 API Visibility Responsibility Response time Memory requirements Externally visible properties? Reliability Throughput Protocol Cohesion Max clients

26 Don t forget: An architecture is an abstraction of a system!

27 It omits details of the elements

28 The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them.

29 Depends Developed by Synchronizes with Uses Is composed of Relationships among elements? May use Calls Generalizes Spawns Is attached to

30 How to describe an architecture?

31 One view?

32 NO

33 Presentation logic Domain logic Data access Browser Web server Architecture DB = Web server Several structures Browse r Web server DB Web server

34 The SEI model

35 Architectural structures Module Component-and-connector Allocation

36 Module = Unit of implementation (Examples?)

37 What s this module s responsibility?

38 What may a module use?

39 What does a module use?

40 (Why are these questions important?)

41 Component-and-connector

42 Component = Unit of computation (or data store) (Examples?)

43 Connector = Communication between components (Examples?)

44 What s executing in the system?

45 How do components interact?

46 How does data flows?

47 What s replicated?

48 (Why are these questions important?)

49 Allocation

50 In which hardware does the system run?

51 Who developed each module?

52 Where are the files implementing this?

53 (Why are these questions important?)

54 Allocation structures map software elements into external elements

55 To summarize...

56 How is the system to be structured as a set of code units?

57 Modules

58 How is the system to be structured as a set of elements that have runtime behavior and interactions?

59 Component and Connector

60 How is the system to relate to CPUs, file systems, development teams, networks,...?

61 Allocation

62 3 types Module Component-and-connector Allocation

63 So, we need 3 views, right?

64 NO

65 These are view types

66 Each view type may have many architectural styles

67 Module C & C Allocation Decomposition Pipe-and-Filter Deployment Uses Client-Server Install Generalization Peer-to-Peer Work assignment Layered Service-Oriented Architecture Aspects Publish- Subscribe Data Model Shared-Data Multi-tier

68 Do we need so many views?

69 It depends...

70 Module C & C Allocation Decomposition Pipe-and-Filter Deployment Uses Client-Server Install Generalization Peer-to-Peer Work assignment Layered Service-Oriented Architecture Aspects Publish- Subscribe Data Model Shared-Data Building blocks Multi-tier