Software Architecture Flashcards

Architectural Design Overview

• Architectural design is crucial in software engineering as it focuses on how a software system is organized.

Topics Covered

• Architectural design decisions
• Architectural views
• Architectural patterns
• Application architectures

Software Architecture

• Definition: The design process that identifies subsystems forming a system and their control and communication framework.
• Output: A description of the software architecture.

Architectural Design Process

• Early Stage: Represents the bridge between specification and design, often developed alongside specification activities.
• Elements: Involves identifying significant components and their communication methods.

Architectural Abstraction

• Architecture in the Small: Focuses on individual program components.
• Architecture in the Large: Concerns complex systems, often across multiple distributed computers.

Advantages of Explicit Architecture

• Stakeholder Communication: Architecture serves as a focal point for stakeholder discussions.
• System Analysis: Enables analysis of non-functional requirements.
• Large-scale Reuse: Promotes the reusability of architecture across various systems, supports product-line architectures.

Architectural Representations

• Documentation: Predominantly done using informal block diagrams; noted for lacking semantic richness.
• Architectural Models: Semantics depend on model usage, essential for effective communication and documentation.

Architectural Models and Design Decisions

• Involves multiple common decisions impacting non-functional characteristics, such as:
  • Suitable application architecture
  • System distribution methods
  • Appropriate architectural styles
  • Structure and decomposition of the system
  • Control strategies for system management
  • Evaluation and documentation of architecture

Architecture Reuse

• Similar architectures across domain-specific systems can enhance efficiency and comprehension.
• Developments often use architectural patterns or styles to capture essential architecture features.

System Characteristics in Architecture

• Performance: Minimize communication and localize critical operations.
• Security: Implement layered architecture for critical assets.
• Safety & Availability: Include redundancy and fault tolerance mechanisms.
• Maintainability: Employ fine-grain components for easy replacement.

Architectural Views Overview

• Architects utilize multiple perspectives including:
  • Logical view (key abstractions as objects/classes)
  • Process view (interacting processes at run-time)
  • Development view (software decomposition for development)
  • Physical view (hardware distribution of software components) along with use cases or scenarios.

Architectural Patterns

• Definition: Standard methods of design representing good practices that have been tested.
• Should detail applicability, advantages, and use cases.

Model-View-Controller (MVC) Pattern

• Components:
  • Model: Manages data.
  • View: Presentation layer to the user.
  • Controller: Handles user interactions.
• Use Cases: Suitable for systems requiring multiple data views or unknown presentation needs.
• Advantages: Independent data representation changes; supports various views.

Layered Architecture

• Structures systems into layers providing specific services.
• Supports incremental subsystem development with minimal impact on other layers.

Repository Architecture

• Centralizes data management in a repository.
• Advantages: Independence of components; consistent data management.
• Disadvantages: Single point of failure; possible communication inefficiencies.

Client-Server Architecture

• Distributed model organizing services across components.
• Facilitates shared database access and variable loads by replicating servers.

Pipe and Filter Architecture

• Processes data through discrete transformations, commonly used in data processing systems.
• Advantages: Understanding and transformation reuse; ease of addition.
• Disadvantages: Communication format must be agreed upon, may create inefficiencies.

Application Architectures

• Types of Applications: Transaction processing systems, information systems, language processing systems with well-defined structures typical for each type.
• Transaction Processing Systems: Allow remote access and modification of data in databases.
• Language Processing Systems: Translate and execute instructions in source languages, involving various compiler components.

Key Points

• Architectural models guide comparison, validation, and reuse of application systems.
• Understanding different application types aids in designing robust software architectures, enhancing overall user experience and system reliability.