Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Computer Engineering Expert

1. Describe in detail the consistency model of the distributed file system (GFS or AFS). Present the consistency model selected and how it was achieved through design. Clarity of presentation matters, so take your time to formulate your answer clearly.

2. Suppose you are provided a uniprocessor system with one gigabyte of memory and a 300 gigabyte disk. The OS on the machine has a demand paged virtual memory system with a local page replacement policy and a multi-level feedback queue (MLFQ) CPU scheduler. On the system there are two compute-intensive jobs running: Job-A and Job-B. Job-A has a working set of 50 gigabytes while Job-B has a working set of 100 megabytes. Suppose you left the system to execute for a while till it reached a steady state with both jobs running.

a. Which job will you expect to have a higher CPU scheduling priority from MLFQ scheduler?

b. Suppose you add the second CPU to system, how will this affect priorities of the jobs?

c. Suppose you switch from a local to the global page replacement policy, how does this alteration affect priorities of the jobs? Justify your answer and state any assumptions you make.

3. Consider organization of a UNIX file as represented by the inode. Suppose there are 13 direct block pointers and a singly, doubly and triply indirect pointer in each inode. Further, Suppose that system block size and the disk sector size are both 4K. If the disk block pointer is 32 bits, then:

a. Find the maximum file size supported by this system?

b. Supposing no information other than file inode is already in main memory, how many disk accesses are needed to access the byte in position 5Y3+100, where Y=1024?

4.a. Define the term “deadlock”. There are four conditions which should hold before deadlock is possible. Name them.

b. Outline the algorithm which detects whether there is a deadlock. The algorithm must be able to cope with multiple types of resources, each type having a limited number of units available.

c. When must the algorithm be invoked? The answer to this problem might depend on system characteristics like the rate of resource requests, the granularity of resources, and the expected rate of deadlock. List three possible choices and discuss the criteria you will use to choose among them.

5. Assume an instruction takes 1 nanosecond to execute (on average), a page fault takes 20 microseconds of processor time, and it takes 300 microseconds of disk time to read or prepare a single page. Assume that on average, 1/2 of the pages are modified. What is the average number of instructions between page faults which will cause the disk to be busy doing page transfers all the time?

6. List three broad design goals of the ESX memory management system, and briefly outline how the design meets those goals.

7. Consider a system implementing multilevel feedback queue scheduling. What strategy could a computer user employ to maximize amount of CPU time allocated to the user’s process?

8. Your OS has a set of queues, each of which is protected by a lock. To enqueue or dequeue an item, a thread should hold the lock associated to the queue. 
}

You require to implement an atomic transfer routine which dequeues an item from one queue and enqueues it on another. The transfer should appear to occur atomically. This is your first attempt:

void transfer(Queue *q1, Queue *q2) {
Item thing; /* the thing being transferred */
q1->lock.Acquire(); thing = q1->Dequeue(); if (thing != NULL){
q2->lock.Acquire(); q2->Enqueue(thing); q2->lock.Release();
} q1->lock.Release()

You might suppose that q1 and q2 never refer to the same queue. Also, suppose that you have a function Queue::Address which takes a queue and returns, as an unsigned integer, its address in memory.

a. Describe how using this implementation of transfer leads to deadlock; 

b. prepare a modified version of transfer which avoids deadlock and does the transfer atomically;

c. If the transfer does not require to be atomic, how may you modify your solution to achieve a higher degree of concurrency? Justify how your modification increases concurrency.

Computer Engineering, Engineering

  • Category:- Computer Engineering
  • Reference No.:- M91856

Have any Question? 


Related Questions in Computer Engineering

Write a gui application for the webbuy company that allows

Write a GUI application for the WebBuy Company that allows a user to compose the three parts of a complete email message: the "To:", "Subject:" and "Message:" text. The "To:", and "Subject:" Text areas should provide a s ...

Build a weighted graph that models a map of the area where

Build a weighted graph that models a map of the area where you live. Use Dijkstra's algorithm to determine the shortest path from a starting vertex to the last vertex.

Case description and content requirements for the final

Case Description and Content Requirements for the Final Project Case Description - Online Recruiting System (ORS) AppBeyondBorders (ABB) Inc. is a non-profit organization that is committed to well beings of people in the ...

Both turtles and patches can create visual images in the

Both turtles and patches can create visual images in the NetLogo view. Create a turtle and have it draw a circle (using the PEN-DOWN command). Create the outline of a circle with patches without using a turtle pen. Write ...

1 write findmin and findmax methods for the avltree class2

1. Write FindMin and FindMax methods for the AVLTree class. 2. Using the Timing class, compare the times for the methods implemented in Exercise 1 to the same methods in the BinarySearchTree class. Your test program shou ...

Abm and oop agent-based modeling shares many features with

ABM and OOP Agent-based modeling shares many features with object-oriented programming (OOP). In some ways ABM and OOP are very different from each other. OOP describes a class of potential programming languages, whereas ...

1 complete the tutorials that are available in the netlogo

1. Complete the tutorials that are available in the NetLogo User Manual. 2. Look over the models in the Sample Models section of the NetLogo models library. The models are grouped by subject area. Pick out a model you fi ...

1 evaluate the four basic linked list operations for a

1. Evaluate the four basic linked list operations for a sorted doubly linked list and indicate the worst case time-complexities of each. 2. Evaluate the worst case time-complexity for the search operation on a doubly lin ...

Discussion criminal background checksread the article

Discussion: Criminal Background Checks Read the article titled "Why Aren't Business Ethics Classes Making Businesses More Ethical?" located at http://crowell.biola.edu/blog/2013/feb/13/why-ethics-classes-rae/. The Wall S ...

The isvalidsource function can be used to evaluate a c

The isValidSource() function can be used to evaluate a C++ source file, but it is incomplete. Brackets encountered inside comments and literal strings would not be paired with those found elsewhere in the program. (a) C+ ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro