Software Architecture

Question 1

What are the Architecture Characteristics?

Answer 1

(May be dependent on the context of the system)
- specifies operational and design criteria on how to
implement a certain requirement
- influences design aspect so that a (combination of)
components are specified to realize the
requirement? (and not best practice)
- Critical that application performs as intended and
meets (functional and non-func.) requirements

Question 2

Operational Architecture Characteristic

Answer 2

Merkmale:
- Availability (Time interval the system to be online, 
  quick recovery, ...)
- Performance
- Scalability

Question 3

Structural Architecture Characteristic

Answer 3

• Extensibility
• Maintainability
• Configuration

Question 4

Cross-Cutting Architecture Characteristic

Answer 4

Need to be considered across multiple components

• Accessibility (Usable by all users including disabilities)
• Privacy (Data protection,..)
• Security (encryption, authorization,..)

Question 5

Different Types of Architecture Styles

Answer 5

monolithic:
- Layers
- Model-View-Controller
distributed:
- Service-Based
- microservices

Question 6

Layered Architectural Style

Answer 6

Technologically partitioned 
- definition of responsibilities for each layer
Layer types (open, closed)
- request muss pass through closed and can skip open 
  layers
Topology:
- Presentation layer
- Business layer
- Persistence layer
- Database layer

Question 7

Layered Architectural Style - Trade Offs

Answer 7

+ Simplicity and Costs
+ Reliable
-> works well for medium sized systems

• Elasticity and scalability
• performance (parallelization not supported)
• availability (long startup/recovery time)

Question 8

Model-View-Controller (MVC) AS

Answer 8

Separates system in three modules
- Model (Backend & Data)
- View (presentation of the model data (user interface))
- Controller (translates user interaction to operations
on the model)

Question 9

Model-View-Controller - Trade Offs

Answer 9

+ Interactive application (#views not fixed, datat should
be presented differently,…)
+ change propagation mechanism (ensures consistency between view and model on various platforms)

• not all views are interested in all changes
• increased complexity (separate components)
• high dependency between view and controller

Question 10

Service-Based AS

Answer 10

User interface with one or more services that are connected to a common database
- multiple interfaces, services and databases in different arrangements possible
The services are composed of differen components
- domain partitioned service (components realize domain specific tasks)
- technically partitioned service (components in layered structure)