Distributed Systems: Models UPDATED
ACTUAL Exam Questions and CORRECT
Answers
What are the different types of basic distributed system models? - CORRECT ANSWER -
Physical Models
Architectural Models
Fundamental Models
What is a physical model? - CORRECT ANSWER - A representation of the underlying
hardware elements of a distributed system that abstracts from specific details of the computer
and networking technologies employed.
What is a baseline physical model - CORRECT ANSWER - • Hardware and software
components located at networked computers communicate and coordinate their actions only by
passing messages
•Very simple physical model of a distributed system
What are some examples of physical models? - CORRECT ANSWER - Baseline physical
model
Early distributed (LAN)
Internet-scale
Contemporary
What is the difference between the architectural model and fundamental model? - CORRECT
ANSWER - An architectural model is concerned with the placement of its components and
the relationships between them
‣client-server systems
‣peer-to-peer systems
Fundamental models are concerned with a more abstract description of the properties that are
common in all of the architectural models
, What are the 4 building blocks of an architectural model? - CORRECT ANSWER - 1.
Communicating entities
2. Communication paradigms
3. Roles and responsibilities
4. Placement
Communicating entities: what are the entities that are communicating in the distributed system?
(From a system-oriented perspective) - CORRECT ANSWER - ‣communicating entities
are processes
‣distributed system: processes coupled with appropriate interprocess communication paradigms
‣two caveats:
-In primitive environments such as sensor networks, operating systems does not provide any
abstractions, therefore nodes communicate
-in most distributed environments, processes are supplemented by threads (lightweight
processes), so, strictly speaking, it is threads that are endpoints of communication
Communicating entities: what are the entities that are communicating in the distributed system?
(From a programming perspective) - CORRECT ANSWER - Objects
•Computation consists of a number of interacting objects representing units of decomposition for
the problem domain
•Objects are accessed via interfaces
Components
•Resemble objects in that they offer problem-oriented abstractions, also accessed via interfaces
•Difference - Specify assumptions for their interfaces and also the assumptions they make for
other components/interfaces that must hold for their functions to be fulfilled
Web services
•Software application which is identified via URI
•Supports direct interactions with other software agents
-Intrinsically integrated in the WWW, using web standards to represent and discover services
ACTUAL Exam Questions and CORRECT
Answers
What are the different types of basic distributed system models? - CORRECT ANSWER -
Physical Models
Architectural Models
Fundamental Models
What is a physical model? - CORRECT ANSWER - A representation of the underlying
hardware elements of a distributed system that abstracts from specific details of the computer
and networking technologies employed.
What is a baseline physical model - CORRECT ANSWER - • Hardware and software
components located at networked computers communicate and coordinate their actions only by
passing messages
•Very simple physical model of a distributed system
What are some examples of physical models? - CORRECT ANSWER - Baseline physical
model
Early distributed (LAN)
Internet-scale
Contemporary
What is the difference between the architectural model and fundamental model? - CORRECT
ANSWER - An architectural model is concerned with the placement of its components and
the relationships between them
‣client-server systems
‣peer-to-peer systems
Fundamental models are concerned with a more abstract description of the properties that are
common in all of the architectural models
, What are the 4 building blocks of an architectural model? - CORRECT ANSWER - 1.
Communicating entities
2. Communication paradigms
3. Roles and responsibilities
4. Placement
Communicating entities: what are the entities that are communicating in the distributed system?
(From a system-oriented perspective) - CORRECT ANSWER - ‣communicating entities
are processes
‣distributed system: processes coupled with appropriate interprocess communication paradigms
‣two caveats:
-In primitive environments such as sensor networks, operating systems does not provide any
abstractions, therefore nodes communicate
-in most distributed environments, processes are supplemented by threads (lightweight
processes), so, strictly speaking, it is threads that are endpoints of communication
Communicating entities: what are the entities that are communicating in the distributed system?
(From a programming perspective) - CORRECT ANSWER - Objects
•Computation consists of a number of interacting objects representing units of decomposition for
the problem domain
•Objects are accessed via interfaces
Components
•Resemble objects in that they offer problem-oriented abstractions, also accessed via interfaces
•Difference - Specify assumptions for their interfaces and also the assumptions they make for
other components/interfaces that must hold for their functions to be fulfilled
Web services
•Software application which is identified via URI
•Supports direct interactions with other software agents
-Intrinsically integrated in the WWW, using web standards to represent and discover services
