Deck 18: Distributed Process Management

Question 1

One of the earliest proposed approaches to providing distributed mutual exclusion is based on the concept of a distributed queue.

Answer 1

True

Question 2

The operating system knows the current state of all processes in the distributed system.

Answer 2

False

Question 3

Mutual exclusion, deadlock, and starvation are not issues that are faced in a distributed system.

Answer 3

False

Question 4

Algorithms for mutual exclusion and deadlock must depend on access to common memory.

Question 5

A __________ process transfer involves only processes that have not begun execution and hence do not require transferring the state of the process.

A) channel
B) global
C) nonpreemptive
D) preemptive

Question 6

A _________ exists between two processes if they exchange messages.

A) snapshot
B) state
C) global state
D) channel

Question 7

An advantage to nonpreemptive process migration is that it reacts well to sudden changes in load distribution.

Question 8

The negotiation mechanism makes sure that the destination system does not refuse to accept the migration of a process to itself.

Question 9

_________ is the combined state of all processes.

A) Channel
B) Global state
C) Snapshot
D) Distributed snapshot

Question 10

With the __________ strategy, the entire address space at the time of migration is transferred

A) precopy
B) flushing
C) eager (dirty)
D) eager (all)

Question 11

The decision to migrate must be reached jointly by two Starter processes, one on the source node and one on the destination node.

Question 12

Interest in the concept of process migration grew out of research into methods of load balancing across multiple networked systems.

Question 13

Caching is not permitted in the Sprite system.

Question 14

The __________ strategy transfers only those pages of the address space that are in main memory and have been modified.

A) eager (dirty)
B) precopy
C) copy-on-reference
D) eager (all)

Question 15

When a process is migrated, it is necessary to destroy the process on the source system and create it on the target system.

Question 16

It is the delay in communication, coupled with the lack of a common clock, which makes it much more difficult to develop mutual exclusion mechanisms in a distributed system compared to a centralized system.

Question 17

The aim of an algorithm that deals with deadlock is either to prevent the formation of a circular wait or to detect its actual or potential occurrence.

Question 18

Deadlock handling is not complicated in a distributed system because each node has accurate knowledge of the current state of the overall system and every message transfer between processes involves predictable delays.

Question 19

A distributed snapshot algorithm assumes that messages are delivered in the order that they are sent and that no messages are lost.

Question 20

A true global state cannot be determined because of the time lapse associated with message transfer.

Question 21

With __________ a deadlock exists if there is a closed loop, or cycle, in the graph that depicts process dependencies.

A) message deadlock
B) communications deadlock
C) phantom deadlocks
D) resource deadlock

Question 22

A __________ records the state of a process and includes a record of all messages sent and received on all channels.

Question 23

A __________ is a special control message used by an algorithm.

Question 24

In a fully ___________ one node is designated as the control node and controls access to all shared objects.

A) global state
B) distributed state
C) centralized algorithm
D) distributed algorithm

Question 25

"A closed chain of processes exists, such that each process holds at least one resource needed by the next process in the chain," is a description of a __________ .

A) no preemption
B) hold and wait
C) mutual exclusion
D) circular wait

Question 26

With __________ , all processes cooperate in the deadlock detection function.

A) hierarchical control
B) centralized control
C) deadlock control
D) distributed control

Question 27

__________ process migration involves transferring a partially executed process, or at least a process whose creation has been completed.

Question 28

__________ orders events in a distributed system without using physical clocks.

Question 29

In __________ , messages are the resources for which processes wait and deadlock occurs if each process in a set is waiting for a message from another process in the set and no process in the set ever sends a message.

Question 30

_________ is a technique in which a decision is made dynamically whether a given resource allocation request could, if granted, lead to a deadlock.

A) Circular wait
B) Nonpreemptive transfer
C) Deadlock avoidance
D) State

Question 31

When two or more processes compete for the use of system resources, there is a need for a mechanism to enforce __________ .

A) channeling
B) eviction
C) mutual exclusion
D) starvation

Question 32

The transfer of a sufficient amount of the state of a process from one computer to another for the process to execute on the target machine is __________ .

Question 33

The _________ of a process is the sequence of messages that have been sent and received along channels incident with the process.

Question 34

_________ is the permanent blocking of a set of processes that either compete for system resources or communicate with one another.

Question 35

The __________ algorithm can be used to provide a checkpoint of a distributed algorithm to allow rollback and recovery if a failure is detected.

A) channel
B) state
C) distributed snapshot
D) global state

Question 36

__________ means that no resource can be forcibly removed from a process holding it.

A) No preemption
B) Hold and wait
C) Circular wait
D) Mutual exclusion

Question 37

A ________ is the path or means by which the message is transferred.

Question 38

A property of a fully __________ algorithm is that all nodes expend equal effort, on average, in effecting a final decision.

A) eager
B) distributed
C) centralized
D) migrated

Question 39

In _________ , deadlocks occurs if each process in a set of processes requests a resource held by another process in the set.

A) resource deadlocks
B) communications deadlocks
C) allocation deadlocks
D) phantom deadlocks

Question 40

Algorithms for mutual exclusion may be either centralized or __________ .

Question 41

One site is responsible for deadlock detection with _________ control.

Question 42

_________ is when only one process may use a resource at a time and no process may access a resource unit that has been allocated to another process.

Question 43

An alternative approach to mutual exclusion involves the passing of a _________ among participating processes.

Question 44

The __________ method immediately grants the request of an older transaction by killing a younger transaction that is using the required resource.

Question 45

With _________ control, the sites are organized in a tree structure, with one site serving as the root of the tree.