Chapter 19 - OS Distributed Systems
UPDATED ACTUAL Exam Questions and
CORRECT Answers
distributed system - CORRECT ANSWER - A ____________________ is a collection of
processors that do not share memory or
a clock. Instead, each node has its own local memory. The nodes communicate
with one another through various networks, such as high-speed buses and the
Internet
s processors, sites, machines, and hosts (processors in dist sys)
-We mainly use site to indicate the location of a machine and node
to refer to a specific system at a site
4 major reasons**: resource
sharing, computation speedup, reliability, and communication.
resource sharing - CORRECT ANSWER - ________________________ provides
mechanisms for sharing
files at remote sites, processing information in a distributed database, printing
files at remote sites, using remote specialized hardware devices (such as a
supercomputer), and performing other operations
computation speedup - CORRECT ANSWER - a distributed system allows us to distribute
the subcomputations among the various sites. The subcomputations can be
run concurrently and thus provide _________.
load sharing (in a distributed system) - CORRECT ANSWER - if a
particular site is currently overloaded with jobs, some of them can be moved
, to other, lightly loaded sites. This movement of jobs is called _______ or
job migration. Automated _______, in which the distributed operating
system automatically moves jobs, is not yet common in commercial systems.
reliability - CORRECT ANSWER - If one site fails in a distributed system, the remaining
sites can continue
operating, giving the system better ________
communication - CORRECT ANSWER - When several sites are connected to one another
by a _______________________ network,
users at the various sites have the opportunity to exchange information. At
a low level, messages are passed between systems, much as messages are
passed between processes in the single-computer message system discussed
in Section 3.4. Given message passing, all the higher-level functionality found
in standalone systems can be expanded to encompass the distributed system.
Such functions include file transfer, login, mail, and remote procedure calls
(RPCs).
ad- long distance communication
The advantages of distributed systems have resulted in an industry-wide trend toward
downsizing. Many companies are replacing their mainframes with networks of workstations or
personal computers
remote login - CORRECT ANSWER - This command results in the formation of an
encrypted socket connection
between the local machine at UMC, for example, and the "crk.umn.edu"
computer. After this connection has been established, the networking software
creates a transparent, bidirectional link so that all characters entered by the user
are sent to a process on "cs.yale.edu" and all the output from that process is sent
back to the user. The process on the remote machine asks the user for a login
name and a password. Once the correct information has been received, the
UPDATED ACTUAL Exam Questions and
CORRECT Answers
distributed system - CORRECT ANSWER - A ____________________ is a collection of
processors that do not share memory or
a clock. Instead, each node has its own local memory. The nodes communicate
with one another through various networks, such as high-speed buses and the
Internet
s processors, sites, machines, and hosts (processors in dist sys)
-We mainly use site to indicate the location of a machine and node
to refer to a specific system at a site
4 major reasons**: resource
sharing, computation speedup, reliability, and communication.
resource sharing - CORRECT ANSWER - ________________________ provides
mechanisms for sharing
files at remote sites, processing information in a distributed database, printing
files at remote sites, using remote specialized hardware devices (such as a
supercomputer), and performing other operations
computation speedup - CORRECT ANSWER - a distributed system allows us to distribute
the subcomputations among the various sites. The subcomputations can be
run concurrently and thus provide _________.
load sharing (in a distributed system) - CORRECT ANSWER - if a
particular site is currently overloaded with jobs, some of them can be moved
, to other, lightly loaded sites. This movement of jobs is called _______ or
job migration. Automated _______, in which the distributed operating
system automatically moves jobs, is not yet common in commercial systems.
reliability - CORRECT ANSWER - If one site fails in a distributed system, the remaining
sites can continue
operating, giving the system better ________
communication - CORRECT ANSWER - When several sites are connected to one another
by a _______________________ network,
users at the various sites have the opportunity to exchange information. At
a low level, messages are passed between systems, much as messages are
passed between processes in the single-computer message system discussed
in Section 3.4. Given message passing, all the higher-level functionality found
in standalone systems can be expanded to encompass the distributed system.
Such functions include file transfer, login, mail, and remote procedure calls
(RPCs).
ad- long distance communication
The advantages of distributed systems have resulted in an industry-wide trend toward
downsizing. Many companies are replacing their mainframes with networks of workstations or
personal computers
remote login - CORRECT ANSWER - This command results in the formation of an
encrypted socket connection
between the local machine at UMC, for example, and the "crk.umn.edu"
computer. After this connection has been established, the networking software
creates a transparent, bidirectional link so that all characters entered by the user
are sent to a process on "cs.yale.edu" and all the output from that process is sent
back to the user. The process on the remote machine asks the user for a login
name and a password. Once the correct information has been received, the
