The document provides an overview of server hosting and cloud computing, detailing the evolution from traditional remote server rental to modern cloud services. It outlines key concepts of cloud computing, including its on-demand nature, economics, and the technology behind virtualization and service-oriented architecture. Additionally, it discusses prominent cloud service models (IaaS, PaaS, SaaS), major providers like Amazon Web Services and Microsoft Azure, and challenges such as privacy and performance.

1. 15.1
Server Hosting
Renting Remote Servers
• Around for many years and predates
cloud computing – 1990s (?) to present
• Companies provide servers through
Internet that users can rent time on.
• Typically done to host web sites.
• Get whole server for your use
(dedicated server).
• Pay a monthly fee.
• Generally you load whatever software
you want.
• Company only responsible for hardware,
OS.
• Still exists although many companies
have moved into cloud computing also

2. 15.2
Cloud Computing
• Cloud computing – “a model for enabling ubiquitous,
convenient, on-demand network access to a shared pool of
configurable computing resources (e.g., networks, servers,
storage, applications, and services) that can be rapidly
provisioned and released with minimal management effort or
service provider interaction.”*
Came about really as business model to allow business to out-
source their IT software to a third party Cloud provider.
Driven by economics, the Internet and existence of large server
farms.
The word “cloud” comes from drawing cloud shapes to represent
a network.
* Wikipedia: http://en.wikipedia.org/wiki/Cloud_computing

3. 15.3
Some key aspects of cloud computing
1. Computing resources available on demand, thereby
eliminating the need to plan far ahead for provisioning.
2. Elimination of up-front commitment by Cloud users, thereby
allowing companies to start small and increase hardware
resources only when there is an increase in their needs.
3. Ability to pay for use of computing resources on a short-term
basis as needed (e.g., processors by the hour and storage
by the day) and release them as needed, thereby rewarding
conservation by letting machines and storage go when they
are no longer useful.*
* “Above the Clouds: A Berkeley View of Cloud Computing,” University of California at Berkeley
Technical Report No. UCB/EECS-2009-28.

4. 15.4
Difference between renting physical
servers remotely and cloud computing
• In cloud computing, you get a virtual machine running on
servers with your selected OS running on top of
virtualization software.
• There could be other users on servers.
• You access servers through a web service/web site.
• You pay for specific time used on processor, storage
devices and bandwidth/network.
• Cloud computing focuses on virtualization and service
orient approach and making it economical fro companies to
use a third party cloud provider to maintain hardware and
software on a on-demand basis.

5. 15.5
Relationship to Grid computing
• Grid computing – using geographically distributed
computing resources collaboratively began as a concept in
the mid 1990’s with the growth of high speed networks and
the Internet.
• Began in the 1990s as a research concept to provide
collaborative computing
• The word “grid” came from the idea that grid computing
would provide computing power on demand through the
Internet in the same way as electrical power come from a
distributed electrical Grid utility.
• Cost of usage was not a driving force and usually no costs
charged.

6. 15.6
Grid and Cloud Computing
• Both Grid computing and Cloud computing take advantage
of the Internet.
• One angle of Grid computing was “utility computing” from
the original “grid” term.
• Some companies, notably IBM, saw commercial
possibilities in the early 2000’s – “on-demand computing”
but it did not take off then commercially.

7. 15.7
Utility computing resources
Utility computing suggested by John McCarthy in 1960s:
“computation may someday be organized as a public utility."
(Wikipedia).
Grid took it up idea in on-demand computing
Cloud computing followed through with:
1.Maturing of virtualization and service-oriented technologies
2.The growth of large underutilized data centers.

8. 15.8
Technologies underpinning
Cloud computing

9. 15.9
(Hardware) Virtualization
• Method hiding the physical characteristics of a
computer platform. User sees an abstract platform
• Hypervisor - Software that controls this
virtualization. (Word originally derived from 1960’s
“supervisor”.)
• Virtual machine (VM) - a “completely isolated guest
operating system installation within your normal
host operating system”
• User’s programs execute on this virtual machine
but has some access to underlying hardware as
controlled by hypervisor.
• Different OS’s can be provided to individual users
• Performance reduced (how much?) but provides
users with the illusion of their own platform. Users
isolated from each other.
http://en.wikipedia.org/wiki/Hardware_virtualization
http://en.wikipedia.org/wiki/Virtual_machine

10. 15.10
Full and Platform Virtualization
• Full virtualization – complete simulation of underlying
hardware – all instructions, etc.
– Hardware-assisted virtualization – hardware architectural
support provided to allow virtualization
• Platform virtualization – limited simulation of underlying
hardware. Limits what Apps may run.
Server virtualization?

11. 15.11
VMware
• A company started in
1998 providing
virtualization software,
notably hypervisors
• Offers a number of
products
– Cloud Foundry -- free,
open source cloud
computing platform as a
service (PaaS) software
http://en.wikipedia.org/wiki/VMware
http://www.vmware.com/

12. 15.12
Hypervisor Example: Xen hypervisor
and Xen cloud platform
• “Runs directly on the hardware and becomes the interface
for all hardware requests such as CPU, I/O, and disk for the
guest operating systems.”
• Used by Amazon Web Services AWS.
http://www.xen.org/
Open source hypervisor
for x86, x86-64, Itanium,
Power PC, and ARM
processors.
Supports various OS’s
including Linux and
Windows

13. 15.13
Service-oriented Technologies for the
Cloud
• Web services key for user access through the Internet.
Principal Cloud service categories
• Infrastructure as a Service (IaaS)
• Platform as Service (PaaS)
• Software as a Service (SaaS)
Others in literature: Communication as a Service (CaaS), monitoring as a
service (MaaS), Network Cloud services, Datacenter Cloud services,
Compute and Storage Cloud services, Business Application Cloud
services, database as a service, …

14. 15.14
Infrastructure as a Service (IaaS)
“Deliver computer infrastructure – typically a platform
virtualization environment – as a service, along with raw
(block) storage and networking.” *
In IaaS, customers rent computing resources rather than
purchase them and access the resources through a (Web)
service infrastructure. Service billed typically monthly on a
usage basis.
Example: Amazon EC2 (see later)
* http://en.wikipedia.org/wiki/Cloud_computing

15. 15.15
Infrastructure as a Service (IaaS)
Advantages
• Access to preconfigured environment
• Use of latest technology
• Reduced cost and risk of having third party maintain resources
• No capital investment
• No IT personal to maintain remote hardware/software
• Able to manage peak demand as needed without having to
purchase a larger system that would be underutilized at other
times
• Secure – security handed by provider
Disadvantages: Delays in network (Internet), confidential data
concerns, … Discuss

16. 15.16
Software as a Service (SaaS)
“ Software delivery model in which software and its associated
data are hosted centrally (typically in the (Internet) cloud) and
are typically accessed by users using a thin client, normally
using a web browser over the Internet.” *
• Customer pays for access to software that is installed on
providers remote computing resources, typically paid for on a
subscription licensing model.
• Many business software (accounting, email, management
software, …) suitable for SaaS
SaaS example: Google docs
* http://en.wikipedia.org/wiki/Software_as_a_Service

17. 15.17
Software as a Service (SaaS)
Advantages
• Relives businesses of maintaining software - updates.
licenses, multiple copies being consistent… etc.
• Since access is through a web browser, can access software
from anywhere (globally) - mobile device etc.
• Facilitates internal collaboration
• Compatible data - All users use same software version
• No or less dedicated application programming
Disadvantages ? Discuss

18. 15.18
Formed in 1999 focusing
on Software as a Service
(SaaS) and Customer
relationship management
(CRM)
Salesforce.com
http://en.wikipedia.org/wiki/Customer_Relationship_Management
CRM – “strategy for managing a company’s interactions
with customers, clients and sales prospects…
technology to organize, automate, and synchronize
business processes—principally sales activities, but
also … marketing, customer service, and technical
support.”

19. 15.19
Platform as Service (PaaS)
“The delivery of a computing platform and solution
stack as a service.” *
Unlike IaaS, generally not concerned with creating
your own application software or selecting an OS.
Users may develop their own web client interfaces
Advantages derive from SaaS?
Integrated software solution
PaaS example: Google AppEngine
* http://en.wikipedia.org/wiki/Platform_as_a_service

20. 15.20
Major Cloud Providers

21. 15.21
Amazon Web
Services
(AWS)
Amazon started as an
on-line bookstore
in1994/5
Large server farms for
their online business,
led to offering servers
to users through
Amazon Web Services
(AWS) in 2006.
Google moved into cloud
computing in same way having
large available server farms.

22. 15.22
• Amazon led cloud deployment with their AWS
• They realized their large underutilized data centers
could be put to good use by providing cloud
computing to customers.
• AWS - a collection of remote computing (web)
services offered over the Internet (HTTP with
REST/SOAP protocols)
• Notable:
• Amazon EC2 – Amazon Elastic Compute Cloud – rent
virtual computers to run your own applications. Launched
2006. Full production in 2008.
• Amazon S3 – Amazon Simple Storage Service - provides
storage thro web service interfaces. Launched 2006
http://en.wikipedia.org/wiki/Amazon_Web_Services
http://en.wikipedia.org/wiki/Amazon_EC2
http://en.wikipedia.org/wiki/Amazon_S3

23. 15.23
Amazon Elastic Compute Cloud (EC2)
• Uses Xen virtualization to create an instance
• Various packaged instances, see next
• Computing power defined by Elastic Compute Unit
(ECU)
– One EC2 Compute Unit equivalent CPU capacity of a
1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor.
– 33.5 EC2 Compute Units = 2 x Intel Xeon X5570, quad-
core “Nehalem” architecture
• “Elastic” implies can quickly grow and shrink
available computing power (within minutes) – user
has to use AWS APIs and commands do do this?

24. 15.24
AWS instances (2011)
http://aws.amazon.com/ec2/
• Standard Instances
– Small Instance (Default) 1.7 GB memory, 1 EC2 Compute Unit (1 virtual
core with 1 EC2 Compute Unit), 160 GB local instance storage, 32-bit
platform
– Large Instance 7.5 GB memory, 4 EC2 Compute Units (2 virtual cores
with 2 EC2 Compute Units each), 850 GB local instance storage, 64-bit
platform
– Extra Large Instance 15 GB memory, 8 EC2 Compute Units (4 virtual
cores with 2 EC2 Compute Units each), 1690 GB local instance storage,
64-bit platform
• Micro Instances – to add burst capacity
• High-Memory Instances – increased memory
• High-CPU Instances – increase CPU performance
• Cluster Compute Instances – cluster configurations
• Cluster GPU Instances - GPU cluster configurations

25. 15.25
Amazon Simple Storage Service (S3)
Provides storage thro web service interfaces. Launched 2006
Data organization
– Write/read/delete objects (1 byte to 5 TB each)
– Each object stored in bucket retrieved by unique developer
assigned key
– Buckets stored in one of several regions: US Standard, EU
(Ireland), US West (Northern California), Asia Pacific
(Singapore), Asia Pacific (Tokyo)
– Objects kept in one region (unless you transfer them out)
– Authentications mechanism – private, public or rights to
specific user
http://aws.amazon.com/s3/

26. 15.26
Amazon Simple Storage Service (S3)
continued
– REST or SOAP interfaces.
– Access using HTTP (BitTorrent available)
– Reliability: Defined in Service level Agreement: Monthly
Uptime Percentage of at least 99.9% during any monthly billing
cycle.
– Data stored on multiple devices. 99.999999999% durability
(will survive permanently) and 99.99% availability of objects
over a given year.
http://aws.amazon.com/s3/

27. 15.27
S3 costs (2011)
Sliding Scale. Briefly:
Storage
First 1 TB / month $0.140 per GB $0.093 per GB
….
Over 5000 TB / month $0.055 per GB $0.037 per GB
Data transfer costs
None within region or into region via HTTP COPY request
Out of region charged:
First 1 GB / month $0.000 per GB
Up to 10 TB / month $0.120 per GB
…
New AWS customers receive 5 GB S3 storage, 20,000 Get
Requests, 2,000 Put Requests, and 15GB data transfer out
each month for one year.

28. 15.28
Microsoft
Azure
Microsoft jumped
into cloud
computing with
Azure cloud
software in 2008.
Apart from
software for
Windows
platforms,
provides data
centers in US,
Europe and
Asia.

29. 15.29
http://www.microsoft.com/windowsazure/features/

30. 15.30
Eucalyptus

31. 15.31
Some key Cloud Computing Issues
• Privacy and security
• Compliance and legal
• Performance, availability, durability, …
• Standards

32. 15.32

33. 15.33
Using Cloud computing in Distributed
High Performance Computing (HPC)
AWS EC2 provides instances for HPC:
•High-CPU Instances
– High-CPU Medium Instance 1.7 GB of memory, 5 EC2 Compute Units (2 virtual
cores with 2.5 EC2 Compute Units each), 350 GB of local instance storage, 32-bit
platform
– High-CPU Extra Large Instance 7 GB of memory, 20 EC2 Compute Units (8 virtual
cores with 2.5 EC2 Compute Units each), 1690 GB of local instance storage, 64-bit
platform
•Cluster Compute Instances
– Cluster Compute Quadruple Extra Large 23 GB memory, 33.5 EC2 Compute Units,
1690 GB of local instance storage, 64-bit platform, 10 Gigabit Ethernet
•Cluster GPU Instances
– Cluster GPU Quadruple Extra Large 22 GB memory, 33.5 EC2 Compute Units, 2 x
NVIDIA Tesla “Fermi” M2050 GPUs, 1690 GB of local instance storage, 64-bit
platform, 10 Gigabit Ethernet
One EC2 Compute Unit (ECU) provides the equivalent CPU capacity of a
1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor.

34. 15.34
MapReduce
“Introduced by Google in 2004 “to support distribute computing
on large data sets on clusters of computers.”*
Computational processing occurs using two basic steps:
"Map step: The master node takes the input, partitions it up into smaller
sub-problems, and distributes those to worker nodes. A worker node may
do this again in turn, leading to a multi-level tree structure. The worker node
processes that smaller problem, and passes the answer back to its master
node.
"Reduce step: The master node then takes the answers to all the sub-
problems and combines them in some way to get the output – the answer to
the problem it was originally trying to solve.”*
Used at Google. Apache Hadoop is an implementation of MapReduce.
MapReduce using Hadoop available in AWS “Amazon Elastic MapReduce”
* http://en.wikipedia.org/wiki/Mapreduce

35. 15.35
Questions?

36. 15.36
What type of Cloud service is Amazon Web
services (AWS)?
a) Infrastructure as a Service (IaaS)
b) Platform as Service (PaaS)
c) Software as a Service (SaaS)
d) Other
Quiz Questions

37. 15.37
What type of Cloud service is Microsoft Azure?
a) Infrastructure as a Service (IaaS)
b) Platform as Service (PaaS)
c) Software as a Service (SaaS)
d) Other

38. 15.38
Reading materials
Cloud fundamentals:
Michael Armbrust et al, “Above the Clouds: A Berkeley View
of Cloud Computing,” Technical Report No. UCB/EECS-
2009-28
http://www.eecs.berkeley.edu/Pubs/TechRpts/2009/EECS-
2009-28.html
READING ASSIGNMENT: READ ABOVE TECHNICAL
REPORT – to discuss
Video: CS309A Cloud Computing, Stanford University,
http://myvideos.stanford.edu/player/slplayer.aspx?
course=CS309A&p=true
ASSIGNMENT: WATCH ABOVE VIDEO – to discuss

39. 15.39
Reading materials
Books:
“Cloud Computing Implementation, Management and
Security” by J. W. Rittinghouse and J. F. Ransome, CRC
Press, 2010. ISBN 978-1-4398-0680-7.
“Cloud Computing Explained 2nd
ed.” by J. Rhoton, Recursive
Press, 2010, ISBN 978-0-9563556

40. 15.40
HPC:
C.Evangelinos and C. N. Hill, “Cloud Computing for parallel Scientific HPC
Applications: Feasibility of running Coupled Atmosphere-Ocean Climate Models on
Amazon’s EC2, CCA-08.
MapReduce/Hadoop …