COMP 212-DISTRIBUTED SYSTEMS
EXAM QUESTIONS WITH
100%VERIFIED ANSWERS
How is a spanning tree of a network given? - ✔✔• Network G = (V, E)
• Eʹ ⊆ E specifies a spanning tree T = (V, Eʹ)
• Root: u0 (leader)
• Processors know T in a distributed way
• Each u "i" knows: a parent "i", a set children
Time complexity of spanning tree broadcasting - ✔✔Depth d of T
Communication complexity of spanning tree broadcasting - ✔✔n - 1 messages
Time complexity of spanning tree construction - ✔✔O(D) where D is the maximum
distance of a u "i" from u "0" in G
Communication complexity of spanning tree construction - ✔✔-size of messages:
sends message M and an id
-O(m) messages: where m denotes the # of edges of G
Does leader election work on a directed ring with identical processors? - ✔✔No
Does leader election work on a directed ring with unique id processes? - ✔✔Yes
LCR Algorithm - ✔✔Used when we know the unique ids of a network.
Uses only transmission and comparison of ids to select a leader
Time complexity of LCR - ✔✔N rounds
,Communication complexity of LCR - ✔✔- size of messages: encoding in bits of
the maximum id
-O(n^2) messages in worst case
Strongly connected graph - ✔✔A directed graph is strongly connected if there is a path
from every node to every other node.
Floodmax Algorithm - ✔✔Used when we know the unique ids and diameter of the network
Uses transmissions, comparison,and storage of ids
Time complexity of Floodmax - ✔✔D + 1 rounds (or D depending on the round model)
Communication complexity of Floodmax - ✔✔-size of messages: encoding in bits of
the maximum id
-D*m messages always (m is the number of directed links in the network)
IP Protocol - ✔✔set of rules used to pass packets from one host to another (network protocol)
TCP Protocol - ✔✔-Connection Oriented Protocol
-Requires recipient to send acknowledgment of each packet received.
-Packets that don't make it are resent
-Ensures data is delivered reliably
(Transport protocol)
HTTP and FTP - ✔✔The Hypertext Transfer Protocol (HTTP) is used to identify
resources and transfer content on the web. Some web pages use the HTTPS protocol, which
adds an additional layer of encryption to make data transfers more secure. The File Transfer
Protocol (FTP) can also be used to transfer data between computers on a network.
, (application protocols)
TCP vs UDP - ✔✔TCP is a connection oriented protocol where UDP is a connection-less.
TCP is suitable for connections the require high reliability and transmission time is less critical.
TCP establishes a connection with counterpart where UDP doesn't have any guarantee that the
packets sent made it to the destination. TCP uses error checking, where UDP does not.
What is a socket? - ✔✔one endpoint of a two-way communication link between two
programs running on the network
Explain how sockets are used - ✔✔1. Processes bind sockets to a connection and read/write
to them.
2. Sockets are bound to a port number so that the TCP layer can identify the application that data
is destined to be sent.
What is a remote procedure call (RPC)? - ✔✔A method that allows programs to
call procedures located on other machines
RPC vs socket-programming - ✔✔RPCs remove the need for the Distributed Systems
programmer to worry about all the details of network programming. Makes "remote"
procedure calls look and work like a "local" procedure call (achieves transparency)
HTTP/HTTPS - ✔✔Hypertext Transfer Protocol. A protocol for controlling how Web
browsers and servers pass information back and forth over the Internet. (Uses the client-server
model)
HTTPS uses encryption.
Remote Method Invocation (RMI) - ✔✔allows a Java program on one machine to invoke a
method on a remote object
What are some resources that are used in DS? - ✔✔Computers, computing power,
data, printers, sensors, mobile devices
EXAM QUESTIONS WITH
100%VERIFIED ANSWERS
How is a spanning tree of a network given? - ✔✔• Network G = (V, E)
• Eʹ ⊆ E specifies a spanning tree T = (V, Eʹ)
• Root: u0 (leader)
• Processors know T in a distributed way
• Each u "i" knows: a parent "i", a set children
Time complexity of spanning tree broadcasting - ✔✔Depth d of T
Communication complexity of spanning tree broadcasting - ✔✔n - 1 messages
Time complexity of spanning tree construction - ✔✔O(D) where D is the maximum
distance of a u "i" from u "0" in G
Communication complexity of spanning tree construction - ✔✔-size of messages:
sends message M and an id
-O(m) messages: where m denotes the # of edges of G
Does leader election work on a directed ring with identical processors? - ✔✔No
Does leader election work on a directed ring with unique id processes? - ✔✔Yes
LCR Algorithm - ✔✔Used when we know the unique ids of a network.
Uses only transmission and comparison of ids to select a leader
Time complexity of LCR - ✔✔N rounds
,Communication complexity of LCR - ✔✔- size of messages: encoding in bits of
the maximum id
-O(n^2) messages in worst case
Strongly connected graph - ✔✔A directed graph is strongly connected if there is a path
from every node to every other node.
Floodmax Algorithm - ✔✔Used when we know the unique ids and diameter of the network
Uses transmissions, comparison,and storage of ids
Time complexity of Floodmax - ✔✔D + 1 rounds (or D depending on the round model)
Communication complexity of Floodmax - ✔✔-size of messages: encoding in bits of
the maximum id
-D*m messages always (m is the number of directed links in the network)
IP Protocol - ✔✔set of rules used to pass packets from one host to another (network protocol)
TCP Protocol - ✔✔-Connection Oriented Protocol
-Requires recipient to send acknowledgment of each packet received.
-Packets that don't make it are resent
-Ensures data is delivered reliably
(Transport protocol)
HTTP and FTP - ✔✔The Hypertext Transfer Protocol (HTTP) is used to identify
resources and transfer content on the web. Some web pages use the HTTPS protocol, which
adds an additional layer of encryption to make data transfers more secure. The File Transfer
Protocol (FTP) can also be used to transfer data between computers on a network.
, (application protocols)
TCP vs UDP - ✔✔TCP is a connection oriented protocol where UDP is a connection-less.
TCP is suitable for connections the require high reliability and transmission time is less critical.
TCP establishes a connection with counterpart where UDP doesn't have any guarantee that the
packets sent made it to the destination. TCP uses error checking, where UDP does not.
What is a socket? - ✔✔one endpoint of a two-way communication link between two
programs running on the network
Explain how sockets are used - ✔✔1. Processes bind sockets to a connection and read/write
to them.
2. Sockets are bound to a port number so that the TCP layer can identify the application that data
is destined to be sent.
What is a remote procedure call (RPC)? - ✔✔A method that allows programs to
call procedures located on other machines
RPC vs socket-programming - ✔✔RPCs remove the need for the Distributed Systems
programmer to worry about all the details of network programming. Makes "remote"
procedure calls look and work like a "local" procedure call (achieves transparency)
HTTP/HTTPS - ✔✔Hypertext Transfer Protocol. A protocol for controlling how Web
browsers and servers pass information back and forth over the Internet. (Uses the client-server
model)
HTTPS uses encryption.
Remote Method Invocation (RMI) - ✔✔allows a Java program on one machine to invoke a
method on a remote object
What are some resources that are used in DS? - ✔✔Computers, computing power,
data, printers, sensors, mobile devices
