csci 578 software architectures
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CSCI 578 Software Architectures. Exam #1 Review. Materials you are responsible for. Chapters 1-7 in the text book All lecture material through intro to Architectural Analysis (Week 7) Homework #1 and #2. Exam. Closed book, closed note Format Write in answers No multiple choice. - PowerPoint PPT PresentationTRANSCRIPT
CSCI 578Software Architectures
Exam #1 Review
Materials you are responsible for
• Chapters 1-7 in the text book
• All lecture material through intro to Architectural Analysis (Week 7)
• Homework #1 and #2
Exam
• Closed book, closed note
• Format– Write in answers– No multiple choice
Material Review
• Canonical elements of software architecture– Component
• computation
– Connector• communication/coordination
– Configuration• topology and constraints
Material Review
• Architectural styles– Codify key constraints and architectural elements
(components, connectors, configurations) found effective used in a family of software systems over a given time period
• Architectural patterns– A set of architectural design decisions that are applicable to a
recurring design problem, and parameterized to account for different software development contexts in which that problem appears.
– Compared to styles, architectural patterns are at a coarser level of granularity (design decisions versus actual architectural elements) and are inherently more domain specific
Material Review• Examples of Architectural Styles
– Client/Server, P2P, Object Oriented, Layered, Data-Flow, Pipe and Filter, Blackboard, Rule Based
• Examples of Architectural Patterns– 3-tier (Stage-Logic-Display), MVC, Sense Compute Control
• Methods of evaluating design methods like styles and patterns– Vocabulary, structural patterns, computational model, invariants,
common examples, disadvantages, specializations
• Methods of design– Greenfield design (entirely fresh start, no baggage)
• Analogy searching, Brainstorming, Literature searching, Morphological Charts, Removing Mental Blocks, Insight from requirements/implementation
Material Review
• Software Connectors– Taxonomy
• 4 main roles– Communication, Conversion, Facilitation, Coordination
• 8 main types– Event, Stream, Procedure Call, Arbitrator, Data Access,
Distributor, Linkage, Adaptor
• Benefits of first-class connectors– Software evolution, separation of concerns,
modularity, pluggability
Material Review
• Architectural Modeling– An architectural model is an artifact that captures some
or all of the design decisions that comprise a system’s architecture
– Architectural modeling is the reification and documentation of those design decisions
• How to choose what to model?– Cost/Benefit Decision
• What do we model?– Structure (Architectural element), static/dynamic
behaviors, functional/non-functional aspects, Views/Viewpoints
Material Review
• Architectural Modeling– Important things to “get right”
• Consistency, Accuracy/Precision, Ambiguity
– How do we evaluate modeling techniques?• Scope/Purpose, Basic Elements, Style, Static/Dynamic
Aspects, Dynamic Modeling, Non-functional aspects, ambiguity, accuracy/precision, viewpoints, view consistency
– Modeling approaches• Generic, early ADLs, style-specific and domain-specific
languages, extensible ADLs
Material Review
• Architectural Modeling– Generic approaches
• Natural language, informal graphical tools (Powerpoint), semi-formal graphical tools with semantics (UML)
– Early ADLs• Darwin, Rapide, Wright
– Domain/Style-specific ADLs• Koala, Weaves, AADL
– Extensible Architecture Description Languages• xADL, ACME, ADML
Material Review
• Architectural Visualization– An architectural visualization defines how
architectural models are depicted, and how stakeholders interact with those depictions
– Two key aspects here:• Depiction is a picture or other visual
representation of design decisions• Interaction mechanisms allow stakeholders to
interact with design decisions in terms of the depiction
Material ReviewModelViz
One (canonical) visualization(common)
Model
Viz
Viz
Viz
Many visualizations for one model (common)
Model
Model Model
Viz
One visualization bringing together many models (uncommon)
Material Review
• Kinds of Architectural Visualizations– Textual (XML in a text editor, natural language, etc.)– Graphical (boxes, lines, etc.)– Hybrid (combine elements of textual and graphical)– Effect (depict the results or effects of design
decisions, not direct design decisions)• How do we evaluate architectural visualizations?
– Scope/Purpose, Basic Type, depiction, interaction, fidelity, consistency, comprehensibility, dynamism, view coordination, aesthetics, extensibility
Material Review
• Architectural Analysis– The activity of discovering important system
properties using the system’s architectural models.• Early, useful answers about relevant architectural aspects• Available prior to system’s construction
– Formal/Informal• Largely dependent on the underlying architectural model’s
expressivity
– Concerns• Goals, Scope, Primary architectural concern, level of
formality, Type, Level of automation, System stakeholders
Material Review• Architectural analysis
– Completeness• Does the architectural analysis take all the system elements
(components/connectors/etc.) into account? Does it take the other aspects (requirements, etc.) into account?
– Consistency• Do the results of analysis on one subset of a software system produce non
contradictory results with respect to the analysis of another (perhaps non-disjoint) subset?
– Name, Interface, Behavior, Interaction, Refinement
– Compatibility• Do the results of analysis conform to the expected properties/results of the
specific domain, style, or reference architecture?
– Correctness• Does the architectural analysis really represent properties of the full system
specification? Does the system implementation represent the predicted analysis?
Material Review
• Architectural analysis– Scope
• Component/Connector• System/Subsystem• Data• Refinement/Abstraction levels• Comparing architectures/analysis
– Techniques for analysis• Inspection-based, Model-based, Simulation-based