Distributed Systems

Question 1

What is a distributed system?

Answer 1

A collection of loosely coupled nodes interconnected by a communication network

Question 2

What are nodes in a distributed system?

Answer 2

An individual computer or server that is part of a larger system

Question 3

Advantages of Distributed Systems

Answer 3

Reliability
Scalability
Flexibility
Speedup
Openness
High performance

Question 4

Disadvantages of Distributed Systems

Answer 4

Difficult troubleshooting
Less software support
High network infrastructure costs
Security issues

Question 5

Distributed systems: Resource sharing

Answer 5

A user at one site may be able to use the resources available at another

Question 6

Distributed systems: Computation speedup

Answer 6

Sub-computations can be distributed among the various sites and run simultaneously

Question 7

Distributed systems: Reliability

Answer 7

If one site fails in a distributed system, the remaining sites can continue operating

Question 8

Distributed systems: Communication

Answer 8

Users at various sites can exchange information at different levels

Question 9

What is a process in a distributed system?

Answer 9

A program being executed

Question 10

How do processes communicate?

Answer 10

Using inter-process communication if within same host. Exchange messages across network if in different end systems

Question 11

What is a client?

Answer 11

The process that initiates the communication

Question 12

What is a server?

Answer 12

The process that waits to be contacted to begin the session

Question 13

What are sockets?

Answer 13

Where a client and server process communicate with each other by reading from and writing to

Question 14

What are the two socket types?

Answer 14

UDP and TCP

Question 15

UDP (User Datagram Protocol)

Answer 15

Is connectionless, unreliable where group of bytes (datagram) is sent through the socket

Question 16

TCP (Transmission Control Protocol)

Answer 16

Is connection-oriented, reliable where a stream of bytes is sent through the socket

Question 17

What is an Echo server network application?

Answer 17

Simple client server program that sends and received echoes from client to server

Question 18

What is a single client knock-knock network application?

Answer 18

Client-server program that implements the knock-knock jokes

Question 19

RPCs (Remote Procedure Calls)

Answer 19

RPCs allow a client to call a procedure on a remote host

Question 20

What are pipes?

Answer 20

Acts as a channel allowing two processes to communicate

Question 21

Ordinary pipes

Answer 21

Allow communication in standard producer-consumer style

Question 22

How do ordinary pipes work?

Answer 22

Producer write to one end and consumer reads from other end. They are unidirectional and require parent-child relationship

Question 23

What are names pipes?

Answer 23

Several processes can use the named pipe for communication and allows inter-process communication over a network. They are bidirectional