2. (a) What is an HTTP Servlet and what are its main methods in Java EE?...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
2. (a) What is an HTTP Servlet and what are its main methods in Java EE? Briefly describe how servlets are used by other Java EE technologies. (b) Let us assume that the following transactions T and U will be executed on the same server. T: balance = a.getBalance(); a.setBalance(balance + 40); U: balance = a.getBalance(); a.setBalance(balance *2); Transaction T increases the balance of account a. Transaction U doubles the balance of account a. i. Could the 'Lost Update' problem happen when the operations of these two transactions are executed in some order? If so, how could this be prevented using two-phase locking and exclusive locks? ii. Could the 'Dirty Read' problem happen when the operations of these two transactions are executed in a serially equivalent manner? If so, does that depend on when T and U commit or abort and why? 2. (a) What is an HTTP Servlet and what are its main methods in Java EE? Briefly describe how servlets are used by other Java EE technologies. (b) Let us assume that the following transactions T and U will be executed on the same server. T: balance = a.getBalance(); a.setBalance(balance + 40); U: balance = a.getBalance(); a.setBalance(balance *2); Transaction T increases the balance of account a. Transaction U doubles the balance of account a. i. Could the 'Lost Update' problem happen when the operations of these two transactions are executed in some order? If so, how could this be prevented using two-phase locking and exclusive locks? ii. Could the 'Dirty Read' problem happen when the operations of these two transactions are executed in a serially equivalent manner? If so, does that depend on when T and U commit or abort and why?
Expert Answer:
Answer rating: 100% (QA)
The question youve provided seems to be a multipart one related to HTTP Servlets and transactional issues in a concurrent database setting I will address each part of the question in turn a What is an ... View the full answer
Related Book For
Income Tax Fundamentals 2013
ISBN: 9781285586618
31st Edition
Authors: Gerald E. Whittenburg, Martha Altus Buller, Steven L Gill
Posted Date:
Students also viewed these programming questions
-
Planning is one of the most important management functions in any business. A front office managers first step in planning should involve determine the departments goals. Planning also includes...
-
On August 29, 2005, Hurricane Katrina caused severe damage to oil installations in the Gulf of Mexico. Although this damage could eventually be repaired, it resulted in a substantial reduction in the...
-
Car A is due north of Car B. In the Earth frame, Car A is moving south and Car B is moving East. What direction is Car B moving as seen by Car A? north south east west north and east north and west...
-
1. Assume you are assisting one of the businesses with incident response - what one thing should they focus on given their situation? 2. Research and explain a recent well published cyber-attack or...
-
A salesperson must travel to eight cities to promote a new marketing campaign. How many different trips are possible if any route between cities is possible?
-
In each of the following situations, indicate the statistical analysis you would conduct and the appropriate test or test statistic that should be used. a. Respondents in a survey of 1,000 households...
-
The Wall Street Journal reported that automobile crashes cost the United States $162 billion annually (The Wall Street Journal, March 5, 2008). The average cost per person for crashes in the Tampa,...
-
Evaluate the reliability of the hardness test. Consider the following: - No known hardness for each material. Prior to the test we did not know the BHN of each material, therefore we didn't have a...
-
Several years ago, management at Tuglar Corporation established a grievance committee composed of employees who volunteered to work toward the amicable resolution of disputes between Tuglar...
-
Morrow Corporation had only one job in process during May, job X32Z, and had no finished goods inventory on May 1. X32Z work started in April and was completed during May. The data related to that...
-
What is tax planning? Describe the current tax rate structure and explain why it is considered progressive.
-
Briefly describe each of the following programs for deferring taxes to retirement. a. 401(k) plans b. Keogh plans c. Individual retirement arrangements (IRAs)
-
What is a limited liability company (LLC) and why has it become a popular business entity?
-
In a typical mammalian cell, the net transport by the sodium potassium exchange pump that maintains the 70 mV membrane potential is 500 singly charged ions per second. How much work does the pump do...
-
Distinguish a cumulative preferred share from a callable preferred share. Do cumulative dividend provisions and call features affect the investment merits of preferred issues? Explain.
-
Steve is a milkman. He mixes 3 liters of water to every 7 liters of milk and sells at 20% more price than the price at which he bought milk. Assuming that water cost free, what will be the profit...
-
Write a while loop that uses an explicit iterator to accomplish the same thing as Exercise 7.3. Exercise 7.3. Write a for-each loop that calls the addInterest method on each BankAccount object in a...
-
Larry Gaines, age 42, sells his personal residence on November 12, 2012, for $144,000. He lived in the house for 7 years. The expenses of the sale are $10,500, and he has made capital improvements of...
-
Dr. Ivan I. Incisor and his wife Irene are married and file a joint return for 2012. Ivan's Social Security number is 477-34-4321 and he is 48 years old. Irene I. Incisor's Social Security number is...
-
Steve Drake sells a rental house on January 1, 2012, and receives $130,000 cash and a note for $55,000 at 10 percent interest. The purchaser also assumes the mortgage on the property of $45,000....
-
If the angle between vectors \(\vec{A}\) and \(\vec{B}\) is \(110^{\circ}\) and if \(A=1.7 \mathrm{~N}\) and \(B=2.0 \mathrm{~m}\), what is the value of \(\vec{A} \cdot \vec{B}\) ?
-
You throw a textbook to a friend who is at their dormitory window \(2.2 \mathrm{~m}\) above you. You are standing \(4.0 \mathrm{~m}\) away from the building and your throw is perfectly made such that...
-
A force \(\vec{F}=F_{x} \hat{\imath}+F_{y} \hat{\jmath}\) with \(F_{x}=50 \mathrm{~N}\) and \(F_{y}=12 \mathrm{~N}\) is exerted on a particle as the particle moves along the \(x\) axis from \(x=1.0...
Study smarter with the SolutionInn App