Distributed Systems Test 1 UPDATED
ACTUAL Exam Questions and CORRECT
Answers
What is a distributed system? - CORRECT ANSWER - One in which hardware or
software components located at networked computers communicate and coordinate their actions
only by passing messages
Characteristics/Key Challenges of Distributed Systems - CORRECT ANSWER -
1.Heterogeneity - many types of hardware and software; handled by middleware and mobile
code
2.Openness - seamless extension, easy to expand; requires interfaces, communication
mechanisms and standards
3.Security - CIA model
4.Scalability - add resources within appropriate costs
5.Failure Handing - Failures should be partial, not take down the whole system
6.Concurrency - independent processes run simultaneously; resources must be managed
7.Transparency - system must be perceived as whole
8.Quality of Service - Reliable, secure, good performance; deadlines
Methods of Failure Handling - CORRECT ANSWER - Detect a failure
Mask the failure
Tolerate the failure
Recover from the failure
Redundancy
Types of Transparency - CORRECT ANSWER - Access - remote and local access use
same commands
Location - no physical address knowledge requirements
Concurrency - no interference between running processes
, Replication - multiple instances of resource used without user knowledge of existence
Failure - faults must be concealed so processes and applications can continue to run
Mobility - resources and clients in a system are able to move
Performance - system can reconfigure based on loads
Scale - system can increase in size without change to structure or applications
Want for distributed systems - CORRECT ANSWER - Sharing of resources allows for
significantly higher power than any individual computer. Allows performing of tasks that
wouldn't happen otherwise. Allows communications and collaborations to exist that wouldn't
otherwise
Message Passing - CORRECT ANSWER - a relationship between objects permitting
communication; transmission of information
Resource Sharing - CORRECT ANSWER - Allowing multiple devices and processes
access to available resources in a system. The key goal of distributed systems
No Global Clock - CORRECT ANSWER - There is no perfect clock synchronization in a
distributed system. Clocks can drift, so no part of a system can know the exact time of any other
part of the system
Trends in Distributed Systems - CORRECT ANSWER - Pervasive Networking -
Collections of connected networks
Ubiquitous computing - Computing embedded into everyday objects
Mobile Computing - Being able to perform tasks on the go
Multimedia Services - media access and streaming
Systems as a Utility - resource sharing
Client - CORRECT ANSWER - Computer that sends a request to a server
ACTUAL Exam Questions and CORRECT
Answers
What is a distributed system? - CORRECT ANSWER - One in which hardware or
software components located at networked computers communicate and coordinate their actions
only by passing messages
Characteristics/Key Challenges of Distributed Systems - CORRECT ANSWER -
1.Heterogeneity - many types of hardware and software; handled by middleware and mobile
code
2.Openness - seamless extension, easy to expand; requires interfaces, communication
mechanisms and standards
3.Security - CIA model
4.Scalability - add resources within appropriate costs
5.Failure Handing - Failures should be partial, not take down the whole system
6.Concurrency - independent processes run simultaneously; resources must be managed
7.Transparency - system must be perceived as whole
8.Quality of Service - Reliable, secure, good performance; deadlines
Methods of Failure Handling - CORRECT ANSWER - Detect a failure
Mask the failure
Tolerate the failure
Recover from the failure
Redundancy
Types of Transparency - CORRECT ANSWER - Access - remote and local access use
same commands
Location - no physical address knowledge requirements
Concurrency - no interference between running processes
, Replication - multiple instances of resource used without user knowledge of existence
Failure - faults must be concealed so processes and applications can continue to run
Mobility - resources and clients in a system are able to move
Performance - system can reconfigure based on loads
Scale - system can increase in size without change to structure or applications
Want for distributed systems - CORRECT ANSWER - Sharing of resources allows for
significantly higher power than any individual computer. Allows performing of tasks that
wouldn't happen otherwise. Allows communications and collaborations to exist that wouldn't
otherwise
Message Passing - CORRECT ANSWER - a relationship between objects permitting
communication; transmission of information
Resource Sharing - CORRECT ANSWER - Allowing multiple devices and processes
access to available resources in a system. The key goal of distributed systems
No Global Clock - CORRECT ANSWER - There is no perfect clock synchronization in a
distributed system. Clocks can drift, so no part of a system can know the exact time of any other
part of the system
Trends in Distributed Systems - CORRECT ANSWER - Pervasive Networking -
Collections of connected networks
Ubiquitous computing - Computing embedded into everyday objects
Mobile Computing - Being able to perform tasks on the go
Multimedia Services - media access and streaming
Systems as a Utility - resource sharing
Client - CORRECT ANSWER - Computer that sends a request to a server
