software architecture slide 1

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17 what does  component-and-connector structures consist in?

　　　Elements

　　　　components: principal processing units and data stores. A component has a set of ports through which it interacts with other components (via connectors)

　　　　connectors: pathways of interaction between components. connectors have a set of role that indicate how components may use a connector in interactions

　　　Relations

　　　　Attachments: component ports are associated with connector roles to yield a graph of components and connectors.

　　　　Interface delegation: in some situations component ports are associated with one or more ports in an "internal " subarchitectrual. similarly for the roles of a connector.

　　　Constraints

　　　　Components can be attached only to connectors, not other components

　　　　connectors can be attached only to components, not other connectors

　　　　attachments can bemade only between compatible ports and roles

　　　　interface delegation can be defined only between two compatible prots (or two compatible roles)

　　　　connectors cannot appear in isolation; aconnector must be attached to a component

　　　　

16 how to documenting element properties in module structures?

　　Name

　　　　may suggest something about the module's role

　　　　may reflect its position in the decomposition hierarchy

　　Mapping to source code uints

　　　　module account: IAccout.java, AccountImpl.java,AccountOrmMapping.xml

　　Visibility of interfaces

　　　　whe a mocule has submodules, some interfaces of the submodules may have internal purposes; the interces are used only by the submodules within the enclosing parent module.

　　　　　　a Encapsulation： module C provides its own interface, hiding the interfaces of modules A and B

　　　　　　b selective expposition: Module C exposes a subset of the interfaces of modules A and B as its interface

15 what does a Module structure consist?

　　Elements, Relations and constraints

　　Elements are Modules. wich are implementation units of software that provide a coherent set of responsibilities.

　　Relations are Is-part-of

　　　　　　　　Depends-on

　　　　　　　　Is-a

　　Constraints. different module views may impose specific topological constraints, such as limitations on the visibility between modules.

14 what are differences between modules and components?

　　Modules:

　　　　A module is an implementation unit that provides a coherent set of responsibilities.

　　　　A responsibility is a general statement about an architecture element and what it is expected to contribute to the architecture.

　　Components

　　　　Components are the principal computational elements and data stores that execute in a system

　　　　Components interact with each other at runtime to carry out the system's functions.

　　The depicted client-server system consists of two modules, but eleven components.

13 how many categories of architectural structures are there?

　　there are three catagories of architectural structures:

　　　　Module structures

　　　　component-and-connections structures

　　　　allocation structures

12 what is a stakeholder.

　　A stakeholder is anyone with a vested interest in the sucess of the system.

　　Stakeholders have differenct concerns they wish the system to guanrantee or optimize.

11 what kind is UML?

　　UML is a seminotation way.

10 List notation ways for architecture documentation and give their differences.

　　there are three notation ways: Informal notations, semiformal Notation and Formal notations.

　　　　informal notations. 

　　　　　　Views produced using general-purpose diagramming and editing tools.

　　　　　　the sematics of the description are characterized in natural laguage.

　　　　　　they cannoot be formally analyzed.

　　　　semiformal notation

　　　　　　standardized notation that prescribes graphical elements and rules of construction(e.g. UML)

　　　　　　Lacks a complete semantic treatment of the meaning of those elements

　　　　　　rudimentary analysis can be appplied.

　　　　formal notations

　　　　　　views are described in a notation that has a precise semantics (e.g., based on mathematical formalisem)

　　　　　　formal analysis of both syntax and semantics is possible

　　　　　　architecture description languages(ADLs)

　　　　　　support automation through associated tools　　　　　　

9 How many sections does a view template have?

　　A view template will have five sections, which are primary presentation, element catalog, context diagram, variability guide and rationale.

　　　　The primary representation depicts the elements and relations of the view, in the vocabulary of that view.

　　　　The element catalog details at least those elements depicted in the primary presentation.（Primary representation 中各element的介绍）

　　　　A context diagram shows how the system or portion of the system depicted in this view relates to its environment: humans, other systems, pysical objects... (和context之间联系的)

　　　　A variability guide shows how to exercise any variation points that are a part of the architecture shown in this view.（如何exercise(运用吗？)view中的variation points）

　　　　The rationale explains why the design reflected in the view came to be (e.g. justification for the choice of a pattern).

8 Is there an effective way to visualise the software architecture?

　　In Simon Brown's experience, software teams aren't able to effectively visualise the software architecture of their systems.

7 what is architectural views?

　　an architectural view is a representation of an architectural structure accordingto a template in a chosen notation, and used by some system stakeholders.

6 what is documenting architecture?

　　it is a "views and beyond"  approach. Documenting an architecture is matter of documenting the relevant views and then adding documentation that applies to more than one view.

5 what is architectural degradation and recovery?

　　architectural degradation: when a system evolves, ideally its prescriptive architecture is modified first. however, in practice, they system -and thus its decriptive architecture- is often directly modified.

　　architectural recovery is the process of determining a software system's architecture from its implementation-level artifacts.

4 What is prescriptive architecture and descriptive structure?

　　A system's prescriptive structure captures the design decisions made prior to the system's construction.

　　A system's descriptive architecture describes how the system has been built.

3 Is there an architecture if there is no description or specification?

　　An architecture can exist independently of its description or specification.

　　　　a. every system compreses elements and relations among them to support some type of reasoning.

　　　　b. But the architecture may not be known to anyone.

2 what reasoning an architectural strutrue should spport? The reasoning shoudl be about an attribute important to some stakeholder.

1 what structure is architectural?  A structure is architectural if it supports reasoning about the system's properties.