Deck 18: Exploring Distributed File Systems and Grid Computing With NFS, AFS, Coda, and JXTA

Question 1

Which of the following statements is false?

A) Fault tolerance is easier to implement in stateless systems.
B) Stateful systems can reduce the size of request messages.
C) Stateless systems offer better performance.
D) A distributed file server can be either stateful or stateless.

Answer 1

Stateless systems offer better performance.

Question 2

The mechanisms used to ensure file consistency may __________.

A) increase complexity
B) restrict scalability
C) reduce performance
D) All of the above.

Answer 2

All of the above.

Question 3

Which of the following NFS-4 features improves performance?

A) Implementing stateful server.
B) Implementing stateless server.
C) Implementing client-caching scheme through delegation.
D) Using PRCs to communicate between client and server.

Answer 3

Implementing stateful server.

Question 4

NFS-3 supports __________, which allow a server to continue executing before a write has been completed.

A) safe synchronous writes
B) safe asynchronous writes
C) safe concurrent writes
D) safe continuous writes

Question 5

In AFS-1 and AFS-2, the distributed file system cache was updated at the __________ level. In AFS-3, the distributed file system cache was updated at the __________ level.

A) file, block
B) block, file
C) user, server
D) server, user

Question 6

Which of the following about AFS is true?

A) Vice runs at each client to govern access to distributed files.
B) AFS offers stronger security than NFS.
C) AFS is fault tolerant.
D) AFS uses main memory to cache its files.

Question 7

In Coda, servers that store the same volume are known as __________.

A) an available volume storage group (AVSG)
B) a volume storage group (VSG)
C) preferred servers (PS)
D) a virtual file system (VFS)

Question 8

Coda clients enter the __________ when they are connected to Coda.

A) initiation stage
B) hoarding stage
C) emulation stage
D) reintegration stage

Question 9

In Sprite, each __________ represents a piece of the global file hierarchy and is stored at one server.

A) prefix table
B) volume
C) domain
D) token

Question 10

Sprite offers better __________ than that of NFS, AFS and Coda.

A) performance
B) transparency
C) fault tolerance
D) security

Question 11

__________ is an example of grid computing.

A) Earth Simulator
B) Q
C) Green Destiny
D) SETI@HOME

Question 12

The trade-off faced by distributed computing implementation is that __________.

A) scalability is reduced
B) fault tolerance is reduced
C) complexity increases
D) all of the above

Question 13

A __________ cluster is typically used in e-business applications with high user volumes.

A) high-performance cluster
B) high-availability cluster
C) load-balancing cluster
D) high-scalability cluster

Question 14

Which of the following statements is false?

A) Clustering achieves reliability and fault tolerance by providing redundant copies of services and resources in case of failure.
B) Multiprocessor systems are more scalable than clusters.
C) Beowulf is an example of a high-performance cluster.
D) Windows Server 2003 can be used to build both high-availability clusters and load-balancing clusters.

Question 15

Peer-to-peer applications __________.

A) distribute responsibilities and functions among peers in the network
B) never rely on a central server
C) require each peer performs client and server functions
D) both a and c

Question 16

Which of the following statements about peer-to-peer applications is false?

A) Centralized P2P applications follow the client/server relationship.
B) In pure P2P applications, it is difficult to determine who is on the network.
C) Centralized P2P applications simply management tasks, such as monitoring user access.
D) All file-sharing applications are pure P2P applications.

Question 17

__________ is not a pure P2P application.

A) Gnutella
B) KaZaA
C) FreeNet
D) all of the above

Question 18

Searches in both Gnutella and Freenet are examples of __________.

A) centralized searches
B) distributed searches
C) peer searches
D) query searches

Question 19

In JXTA, __________ act as virtual communication channels.

A) pipes
B) advertisements
C) endpoint routers
D) peers

Question 20

JXTA does not address the issue of __________.

A) security
B) network incompatibility
C) network delay
D) platform incompatibility

Question 21

Grid computing __________.

A) requires centralized control of computing resources
B) achieves high performance using spare computer power at little or no cost
C) is less scalable than clustering
D) requires high-speed, dedicated communication channels to operate efficently

Question 22

The __________ grid computing layer coordinates distributed resources.

A) collective layer
B) coordination layer
C) connectivity layer
D) resources layer

Question 23

__________ are examples of thin clients.

A) Applications that require minimal client-side support
B) Applications that require minimal server-side support
C) Applications that use JSP or servlets
D) Applications that do not use JSP and servlets

Question 24

__________ is not one of the functionalities of JSP directives.

A) Inserting Java code
B) Specifying page settings
C) Including content from other resources
D) Specifying custom tag libraries

Question 25

To use a Jini service, a Jini client must know __________.

A) the implementation of the service
B) the interface of the service
C) both the implementation and the interface
D) none of the above

Question 26

When a Jini service registers with a lookup service, the registration is __________.

A) permanent; only the client can remove it
B) permanent; only the lookup service can remove it
C) leased for a specific amount of time, after which it cannot be renewed
D) leased for a specific amount of time, after which it can be renewed

Question 27

A JavaSpaces service provides the __________ operations.

A) read and write
B) read, write and remove
C) read, write and take
D) read, write and put

Question 28

Which of the following statement about JavaSpaces is false?

A) A JavaSpaces service is a Jini service.
B) Objects in a JavaSpaces service belong to a particular client.
C) Multiple processes can access a JavaSpaces service concurrently.
D) An object stored in a JavaSpaces service will remain in the service until its lease expires or until a program removes the object from the JavaSpaces.

Question 29

__________ is not an open standard used in Web services.

A) XML
B) SOAP
C) UDDI
D) DCOM

Question 30

The .NET initiative enables programmers to develop Web services in __________.

A) C, C++ and Java
B) Java, ASP and C++
C) C++, C# and Visual Basic .NET
D) C++ and Visual Basic. NET

Question 31

.NET Web services allow developers to reuse software components that __________.

A) are written in different languages, such as Java and C#
B) reside on different machines only if they use the same platform
C) reside on different machines using different platforms
D) Both a and c