Distributed Systems Exam Prep UPDATED
ACTUAL Exam Questions and CORRECT
Answers
What is a distributed system? - CORRECT ANSWER - A collection of independent
computers that appears to its users as a single coherent system
Four main goals of distributed systems - CORRECT ANSWER - • Making resources
available
• Distribution transparency
• Openness
• Scalability
Making resources available - CORRECT ANSWER - A distributed system should make it
easy for its users to access remote resources and share them in a controlled and efficient way
distribution transparency - CORRECT ANSWER - • It should be able to hide the fact that
its resources are physically distributed across multiple computers
• A distributed system that is able to present itself to users and applications as if it were only a
single computer system is said to be transparent
What are the forms of transparency in distributed systems? - CORRECT ANSWER -•
Relocation transparency
• Replication transparency
• Location transparency
• Migration transparency
• Access transparency
• Concurrency transparency
• Failure transparency
, Openness - CORRECT ANSWER - • Offers services according to standard rules that
describe the syntax and semantics of those services
• Allows an arbitrary process that needs a certain interface to talk to another process that
provides that interface
Benefits of Openness - CORRECT ANSWER - Interoperability, Portability, Extensibility
Open distributed system - CORRECT ANSWER - An open distributed system is a system
that offers services according to standard rules that describe the syntax and semantics of those
services.
Scalability - CORRECT ANSWER - • One of the most important design goals
• Refers to how well a system can adapt to increased demands
• Dimensions that may scale include size, geographical distribution, administratively scalable
• A scalable system still performs well as it scales up along any of the three dimensions.
Scaling Techniques - CORRECT ANSWER - • Hiding communication latencies
• Distribution
• Replication
What are the ACID properties of transactions? - CORRECT ANSWER - • Atomic :
Ensures that all transactions either happen completely or not at all
• Consistent : If the system has certain invariants that must always hold, if they held before the
transaction, they will hold afterward too
• Isolated : This means that if 2 or more transactions are running at the same time, to each of
them and other processes, the final result will look as though all the transactions happened
sequentially
• Durable : Once a transaction commits, no matter what happens, the transaction goes forward
and the results become permanent
ACTUAL Exam Questions and CORRECT
Answers
What is a distributed system? - CORRECT ANSWER - A collection of independent
computers that appears to its users as a single coherent system
Four main goals of distributed systems - CORRECT ANSWER - • Making resources
available
• Distribution transparency
• Openness
• Scalability
Making resources available - CORRECT ANSWER - A distributed system should make it
easy for its users to access remote resources and share them in a controlled and efficient way
distribution transparency - CORRECT ANSWER - • It should be able to hide the fact that
its resources are physically distributed across multiple computers
• A distributed system that is able to present itself to users and applications as if it were only a
single computer system is said to be transparent
What are the forms of transparency in distributed systems? - CORRECT ANSWER -•
Relocation transparency
• Replication transparency
• Location transparency
• Migration transparency
• Access transparency
• Concurrency transparency
• Failure transparency
, Openness - CORRECT ANSWER - • Offers services according to standard rules that
describe the syntax and semantics of those services
• Allows an arbitrary process that needs a certain interface to talk to another process that
provides that interface
Benefits of Openness - CORRECT ANSWER - Interoperability, Portability, Extensibility
Open distributed system - CORRECT ANSWER - An open distributed system is a system
that offers services according to standard rules that describe the syntax and semantics of those
services.
Scalability - CORRECT ANSWER - • One of the most important design goals
• Refers to how well a system can adapt to increased demands
• Dimensions that may scale include size, geographical distribution, administratively scalable
• A scalable system still performs well as it scales up along any of the three dimensions.
Scaling Techniques - CORRECT ANSWER - • Hiding communication latencies
• Distribution
• Replication
What are the ACID properties of transactions? - CORRECT ANSWER - • Atomic :
Ensures that all transactions either happen completely or not at all
• Consistent : If the system has certain invariants that must always hold, if they held before the
transaction, they will hold afterward too
• Isolated : This means that if 2 or more transactions are running at the same time, to each of
them and other processes, the final result will look as though all the transactions happened
sequentially
• Durable : Once a transaction commits, no matter what happens, the transaction goes forward
and the results become permanent
