AUGUST/RESIT

DUBLIN CITY UNIVERSITY
AUGUST/RESIT EXAMINATIONS 2013/2014
MODULE:
PROGRAMME(S):
EC
ECSA
ECSAO
YEAR OF STUDY:
CA485/A – Cloud Computing
BSc in Enterprise Computing
Study Abroad (Engineering & Computing)
Study Abroad (Engineering & Computing)
4,O,X
EXAMINERS:
Dr Kevin Casey
Dr. Declan O'Sullivan
(Ext:5639)
TIME ALLOWED:
2 Hours
INSTRUCTIONS:
Answer 3 questions. All questions carry equal marks.
PLEASE DO NOT TURN OVER THIS PAGE UNTIL YOU ARE INSTRUCTED TO DO SO
The use of programmable or text storing calculators is expressly forbidden.
Please note that where a candidate answers more than the required number of questions, the
examiner will mark all questions attempted and then select the highest scoring ones.
Requirements for this paper (Please mark (X) as appropriate)
Log Tables
Graph Paper
Dictionaries
Statistical Tables
CA485/A – Cloud Computing
August/Resit Examinations 2013/2014
Thermodynamic Tables
Actuarial Tables
MCQ Only – Do not publish
Attached Answer Sheet
Page 1 of 4
QUESTION 1
[TOTAL MARKS: 33]
Q 1(a)
[6 Marks]
Energy proportionality is a desirable feature of cloud computing hardware. Explain
what energy proportionality is with the aid of an example.
Q 1(b)
[12 Marks]
Sneakernets are often overlooked when attempting to move large quantities of data
in or out of the cloud. Explain how a sneakernet works and how it can be used to
move large quantities of data. Ensure you discuss latency and bandwidth in your
explanation.
Q 1(c)
[6 Marks]
Explain what cost associativity is in relation to cloud computing. Can cost
associativity be obtained for all applications or just some? Explain your answer.
Q 1(d)
[9 Marks]
Explain what is meant by scaling latency. From the point of of view of a cloud
customer with a highly variable workload, how does large scaling latency cost them
economically?
[End of Question 1]
QUESTION 2
[TOTAL MARKS: 33]
Q 2(a)
[6 Marks]
Explain how an SaaS service might be implemented on a PaaS service, which might
in turn be implemented on an IaaS service.
Q 2(b)
[12 Marks]
Compare IaaS and PaaS as options for deploying to the cloud. Ensure you explain in
what scenarios each would be a bad option and in what scenarios a good option.
Q 2(c)
Explain what SLAs are and their role in cloud computing.
[6 Marks]
Q 2(d)
[9 Marks]
In the context of IaaS such as Amazon EC2, explain what is meant by provisioning
and de-provisioning. How does virtualisation relate to these activities?
[End of Question 2]
CA485/A – Cloud Computing
August/Resit Examinations 2013/2014
Page 2 of 4
QUESTION 3
[TOTAL MARKS: 33]
Q 3(a)
Identify and explain three cloud security considerations.
Q 3(b)
Explain how the SAML protocol operates.
[6 Marks]
[12 Marks]
Q 3(c)
[3 Marks]
Explain why geographic regionalisation (such as AWS Regions) is necessary in
cloud computing.
Q 3(d)
[12 Marks]
VM escape is a particular concern in IaaS systems with multiple-tenancy. Explain
why. Ensure you explain what VM escape is. Explain how the goal of fast video
emulation in VMs led to the Cloudburst exploit.
[End of Question 3]
QUESTION 4
[TOTAL MARKS: 33]
Q 4(a)
[6 Marks]
One way to characterise cloud vendors' offerings is as either horizontal or vertical.
Distinguish between these classifications of cloud offering.
Q 4(b)
[6 Marks]
Studies have found large differences in the WAN latency between different cloud
vendors. Identify one type of application where a large WAN latency would be a
problem and one application where it would not be an issue.
Q 4(c)
[12 Marks]
Cloud Mobile Hybrids are a particular class of cloud application. With the aid of an
example, explain what a CMH is. What are the main challenges when building and
maintaining a CMH?
Q 4(d)
[9 Marks]
One design principle of MapReduce is to 'keep the computation as close to the data
as possible'. Explain how this principle is achieved in MapReduce.
[End of Question 4]
CA485/A – Cloud Computing
August/Resit Examinations 2013/2014
Page 3 of 4
APPENDICES
[END OF APPENDICES]
[END OF EXAM]
CA485/A – Cloud Computing
August/Resit Examinations 2013/2014
Page 4 of 4