The document discusses cloud computing and data centers. It defines cloud computing as a style of computing where scalable IT capabilities are provided as an internet-based service. It describes the different cloud service models including SaaS, PaaS, and IaaS. It also discusses cloud deployment models like public, private, community and hybrid clouds. The document then explains how growing adoption of cloud computing requires large data centers to host servers. It provides details on data center network architectures, use of Ethernet, and the role data centers play in processing user requests and transactions.

1. Cloud Computing/Data
Centers
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2. As an end-consumer, we’ve been using Cloud for long times:
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3. John McCarthy, scientist:
“…Computing may someday be organized as a public
utility just as the telephone system is a public utility...”
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4. What is Cloud Computing?
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“Cloud computing is a style of computing where
massively scalable IT-related capabilities are provided
as a service across the Internet to multiple external
customers”
“Cloud computing: A pool of abstracted, highly scalable,
and managed infrastructure capable of hosting end-
customer applications and billed by consumption”
“Cloud Computing is a computing model for enabling
convenient and on demand network access to a shared pool
of configurable computing resources (e.g.,
networks, servers, storage, applications, and services) that
can be rapidly released with minimal management effort or
service provider interaction.”

5. Cloud Comuting
● Cloud Computing is a general term used to describe a new class of
computing that takes place over the Internet.
● A collection/group of integrated and networked hardware, software and
Internet infrastructure.
● Using the Internet for communication and transport CC provides
hardware, software and networking services to clients.
● Complexity and details of the underlying infrastructure are hidden from
users.
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6. Cloud Computing covers more than just computing
technology (NIST’s model of cloud computing):
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7. Essential characteristics:
● On-demand self service that enables consumers to unilaterally provision computing
capabilities, such network storage and server time as needed, automatically, without
requiring human involvement.
● Broad network access which ensures that all Cloud functionalities and the resources
are available over the network and can be accessed through standard mechanisms via
thick or thin clients (e.g., laptops, desktops, tablets and mobile phones).
● Resource pooling which allows the computing resources provisioned by the provider to
be pooled, in order to serve numerous consumers using a multi-tenant model, where
different physical and virtual resources are dynamically assigned and reassigned
according to the demands of the consumer.
● Rapid elasticity and scaling that not only allows the functionalities and resources to
scale rapidly outward and inward in accordance to the demands of the consumer, but
also allows those capabilities to be elastically provisioned and released. Pay for use and
as needed
● Measured service that facilitates automatic control and optimization of resource
allocations in addition to providing the capability to monitor, control and report resource
usage, for both the providers as well as the consumers.
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8. Providers offer their services in three flavors:
(Cloud Service Models)
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C
L
O
U
D
S
E
R
V
I
C
E
S
SOFTWARE AS A
SERVICE
PLATEFORM AS
A SERVICE
INFRASTRUCTURE
AS A SERVICE

9. Cloud Software as a Service (SaaS)
● Essentially based on the concept of renting application functionality
from a service provider rather than buying, installing and running
software yourself.
● Consumers typically access these applications from client devices that
support thin client interfaces like a web browser or use Application
Programming Interfaces (API) defined by the hosted software.
● Consumers do not control or manage the underlying infrastructure or
platform
● e.g. Gmail, Google Docs, Salesforce.com and Microsoft Office 365.
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10. Cloud Platform as a Service (PaaS):
● The providers deliver a computing platform using which consumers can
build and deploy their own applications on the Cloud.
● The computing platform typically includes operating systems,
programming libraries and tools that are supported by the service
provider.
● Subscribers do not have access to the underlying Cloud infrastructure,
but they are typically able control the deployed applications and
configuration settings for the application hosting environment.
● Examples of PaaS include: Google App Engine, Microsoft Azure and
Amazon Elastic Beanstalk.
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11. Cloud Infrastructure as a Service (IaaS):
● Delivers compute services, typically in the form of a set of virtual
machines with associated storage, processing capability, and other
relevant resources like network connectivity.
● Some examples of IaaS include: Amazon Cloud Formation, Rackspace
Cloud and Google Compute Engine.
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12. Pyramid of service models in Cloud Computing
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13. Cloud Deployment Models:
● NIST categorizes Clouds deployments as:
 Public
 Private
 Community
 Hybrid
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14. Private Cloud:
● The Cloud infrastructure is exclusively used by a single organization.
● Companies only want to use hosted services and do not want to share
their infrastructure.
● Under Public deployment model, the Cloud functionalities and
resources are made available for open use to the general public.
● Customers access and use hosted Cloud services that are either free
or offered on pay-per-use basis. Generally, public Cloud service
providers like Microsoft, Amazon and Google own and operate their
Cloud infrastructure and offer access to end users via the Internet.
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Public Cloud:

15. Community Cloud:
● The Cloud infrastructure is shared exclusively between organizations
from a specific group or community and have common computing
concerns. The Cloud framework may be owned, managed and
operated by one or more organizations.
● The Cloud infrastructure consists of two or more distinct Clouds
(Public, Private or Community). These composite Clouds remain
unique entities, but they are bound together by standardized
technologies that enable data and application portability.
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Hybrid Cloud:

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Hybrid
Cloud
Connectivity
(Network Access)
Public Cloud
Private Cloud
Private Cloud
The Cloud Provider
Comunity Cloud

17. Benefits of Cloud Computing
● Lower cost (opportunity to many poor nations to catch-up with the IT
revolution, reducing the costs of hardware and software)
● Rapid scaling
● Self service ( no interaction with any of the service providers)
● Anywhere, anytime access
● Multi-tenancy (single instances of software applications to serve
multiple customers)
● Utility service (pay only for computing resources that are used)
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18. Name27.04.2015 18
Content is stored on
THIS computer, we
cannot access this
content from another
device or computer
External
storage, low
capacity
Multiple work stations talk
to one unit that stores
information and data.

19. Cloud Computing and Data Centers
● Growing adoption of Cloud Computing drives service providers into deploying
new data centers.
● Data centers are centers that host hundreds of thousands of servers which
concurrently support many services and applications.
● Data centera are factories that transforms and stores bits.
● https://www.youtube.com/watch?v=avP5d16wEp0
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20. ● Requirements for building data center:
 Power supply (high power supply, generator facility to overcome the
power failure situation)
 Continuous cooling system
 Security system ( fire alarms, proper ventilation in order to remove
smoke, authorised access, video cameras, security-code
access,biometric access,card reader access,locked cabinets…)
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21. Ethernet
● Ethernet has become the most widely used data transport protocol for
networking technology in local area networks (LANs) and data centers
around the world. The main reason is that Ethernet provides a very
cost effective high bandwidth link between servers and switches.
● Ethernet specifications moved from 100Mbps to 1Gbps in about 4
years and then to 10GbE in about another 4 years.
● It has taken about 10 more years to come up with a 100GbE
specification that is useful for data center applications. The reason for
this increase in time has a lot to do with semiconductor technology.
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22. Cloud Computing and Data Centers
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Data center switch network architecture

23. Cloud Computing and Data Centers
● A typical rack may contain on the order of 40 or more servers, so many ToR
switches contain up to 48 10GbE ports and four 40GbE uplink ports which are
connected to aggregation switches.
● Cloud data center ToR switches are evolved from LAN workgroup switches.
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24. ● In the case of the 10GbE ports, lower cost, direct attach copper cabling
can be used for the short distance between the servers and the ToR
switches, which is less than a few meters.
● Optic fibers are used for the ToR switch uplink ports, because they
need to drive longer distances and higher bandwidth.
● Aggregation switches are typically used to connect a number of ToR
switches to a core switch/router.
● The core switch is at the top of the cloud data center network pyramid
and may include a wide area network (WAN) connection to the outside
carrier network.
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25. ● Data centers are not only serving data, but also pulling information
from a variety of servers and running specialized programs based on
user input. For example, a Google map request could spawn some of
the following transactions:
● Determine the device type the client is using (laptop, handheld, etc.).
● Send information to a local search engine to match the map address.
● Based on the match, pull up the appropriate map data and send it to
the client based on device type.
● Based on the match and the user settings, pull up relative nearby
attractions to display on the map and send it to the client.
● Retrieve relative information about the client based on recent web
transaction.
● Use this information to identify shopping history and send targeted
advertising to be displayed on the client’s web page.
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● Traditional server shelf components:

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28. Resources
● S.Kulkarni, P.Agrawal, Analysis of TCP Performance in Data Center
Networks, Springer New York
● Gary Lee, Cloud Networking
● http://www.slideshare.net/ctrlsweb/the-abc-of-data-center
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