Cloud computing

Cloud computing
Ahmed farag mostafa

What is the cloud?

• IT as a service

• Cloud allows access to services without user technical knowledge or control
of supporting infrastructure
What is
• Best described in terms of what happened to mechanical power over 100 yrs
ago
Cloud Computing?
• Now computers are simple devices connected to the larger cloud

• Data processing, storage and software applications that used to run locally
are now being supplied by big central computing stations. They're
becoming, in essence, computing utilities.

What is Cloud Computing?

• is the delivery of computing as a service rather than a product, whereby shared
resources, software, and information are provided to computers and other devices
over a network.

• In addition, the platform provides on demand services, that are always
on, anywhere, anytime and any place.
• Pay for use and as needed, elastic (scale up and down in capacity and
functionalities).

• The hardware and software services are available to the general public .

cloud computing
• Cloud computing provides computation, software applications, data access data
management and storage resources
without requiring cloud users to know the location and other details of the computing
infrastructure.
• Cloud application providers strive to give the same or better service and performance than if
the software programs were installed locally on end-user computers.

• At the foundation of cloud computing is the broader concept of infrastructure convergence
and shared data . This type of data centre environment allows enterprises to get their
applications up and running faster, with easier manageability and less maintenance, and
enables IT to more rapidly adjust IT resources (such as servers, storage, and networking).

• Resource allocation/services can be adjusted
• No need to know physical location or configuration
• Delivery of application via Internet, while business software and data stored on remote
servers

Characteristics

• Virtualization
• Maintenance
• Agility
• Performance
• Accessibility
• location independence[
• Flexibility
• Application programming interface
• Lower cost… pay for what you use!
• Focus on the Core Business
• Reduction of HW and SW requirements at “user-side”
• High Availability
• Reliability

Advantages of Cloud Computing
• Lower computer costs:
– You do not need a high-powered and high-priced
computer to run cloud computing's web-based
applications.
– Since applications run in the cloud, not on the desktop
PC, your desktop PC does not need the processing power
or hard disk space demanded by traditional desktop
software.
– When you are using web-based applications, your PC can
be less expensive, with a smaller hard disk, less
memory, more efficient processor...
– In fact, your PC in this scenario does not even need a CD or
DVD drive, as no software programs have to be loaded and
no document files need to be saved.

• Improved performance:
– With few large programs hogging your computer's memory, you
will see better performance from your PC.
– Computers in a cloud computing system boot and run faster
because they have fewer programs and processes loaded into
memory…
• Reduced software costs:
– Instead of purchasing expensive software applications, you can
get most of what you need for free-ish!
– That is right - most cloud computing applications today, such as
the Google Docs suite, are totally free.
– That is a lot better than paying $200+ for similar Microsoft
Office software - which alone may be justification for switching
to cloud applications.

• Instant software updates:
– Another advantage to cloud computing is that you are no
longer faced with choosing between obsolete software and
high upgrade costs.
– When the application is web-based, updates happen
automatically - available the next time you log into the cloud.
– When you access a web-based application, you get the latest
version - without needing to pay for or download an upgrade.
• Improved document format compatibility.
– You do not have to worry about the documents you create on
your machine being compatible with other users'
applications or operating systems.
– Where Word 2007 documents cannot be opened on a
computer running Word 2003, all documents can be read!
– There are potentially no format incompatibilities when
everyone is sharing documents and applications in the cloud.


• Unlimited storage capacity:
– Cloud computing offers virtually limitless storage.
– Your computer's current 200 Gbyte hard drive is small compared
to the hundreds of Pbytes available in the cloud.
– Whatever you need to store, you can.
• Increased data reliability:
– Unlike desktop computing, in which if a hard disk crashes and
destroy all your valuable data, a computer crashing in the cloud
should not affect the storage of your data.
– That also means that if your personal computer crashes, all your
data is still out there in the cloud, still accessible.
– In a world where few individual desktop PC users back up their
data on a regular basis, cloud computing is a data-safe
computing platform!


• Universal document access:
– That is not a problem with cloud computing, because you do not
take your documents with you.
– Instead, they stay in the cloud, and you can access them
whenever you have a computer and an Internet connection.
– All your documents are instantly available from wherever you
are.
• Latest version availability:
– Another document-related advantage of cloud computing is that
when you edit a document at home, that edited version is what
you see when you access the document at work.
– The cloud always hosts the latest version of your documents; as
long as you are connected, you are not in danger of having an
outdated version.

• Easier group collaboration:
– Sharing documents leads directly to better collaboration.
– Many users do this as it is an important advantages of cloud
computing - multiple users can collaborate easily on
documents and projects.
– Because the documents are hosted in the cloud, not on
individual computers, all you need is an Internet
connection, and you are collaborating.
• Device independence.
– You are no longer tethered to a single computer or network.
– Changes to computers, applications and documents follow
you through the cloud.
– Move to a portable device, and your applications and
documents are still available.

Disadvantages of Cloud Computing

• Requires a constant Internet connection:
– Cloud computing is impossible if you cannot connect
to the Internet.
– Since you use the Internet to connect to both your
applications and documents, if you do not have an
Internet connection you cannot access anything, even
your own documents.
– A dead Internet connection means no work and in
areas where Internet connections are few or
inherently unreliable, this could be a deal-breaker.
– When you are offline, cloud computing simply does
not work.


• Does not work well with low-speed connections:
– Similarly, a low-speed Internet connection, such as
that found with dial-up services, makes cloud
computing painful at best and often impossible.
– Web-based applications require a lot of bandwidth to
download, as do large documents.
– If you are labouring with a low-speed dial-up
connection, it might take seemingly forever just to
change from page to page in a document, let alone to
launch a feature-rich cloud service.
– In other words, cloud computing is not for the
broadband-impaired!


• Can be slow:
– Even with a fast connection, web-based applications
can sometimes be slower than accessing a similar
software program on your desktop PC.
– Everything about the program, from the interface to
the current document, has to be sent back and forth
from your computer to the computers in the cloud.
– If the cloud servers happen to be backed up at that
moment, or if the Internet is having a slow day, you
would not get the instantaneous access you might
expect from desktop applications.


• Features might be limited:
– This situation is bound to change, but today many
web-based applications simply are not as full-featured
as their desktop-based applications.
– For example, you can do a lot more with Microsoft
PowerPoint than with Google Presentation's web-
based offering.
– The basics are similar, but the cloud application lacks
many of PowerPoint's advanced features.
– If you are a power user, you might not want to leap
into cloud computing just yet.

• Stored data might not be secure:
– With cloud computing, all your data is stored on the cloud.
– The questions is How secure is the cloud?
– Can unauthorised users gain access to your confidential data?
– Cloud computing companies say that data is secure, but it is too early
to be completely sure of that.
– Only time will tell if your data is secure in the cloud.
• Stored data can be lost:
– Theoretically, data stored in the cloud is safe, replicated across
multiple machines.
– But on the off chance that your data goes missing, you have no
physical or local backup.
– Put simply, relying on the cloud puts you at risk if the cloud lets you
down.

Cloud models
SaaS
Software as a Service

PaaS
Platform as a Service

IaaS
Infrastructure as a Service

SaaS Software delivery model

• No hardware or software to
manage
• Service delivered through a
browser

SaaS Advantages
• Pay per use
• Security
• Reliability

SaaS Examples
• CRM
• Financial Planning
• Human Resources
• Word processing

Platform delivery model

• Platforms are built upon
PaaS Infrastructure, which is expensive
• Estimating demand is not a
science!
• Platform management is not fun!

Popular services

• Storage
PaaS • Database
• Scalability

Examples

• Google App Engine
PaaS • Mosso
• AWS: S3

IaaS
Infrastructure as a Service

Computer infrastructure
delivery model

Access to infrastructure stack:
– Full OS access
– Firewalls
IaaS – Routers
– Load balancing

Examples

• Flexiscale
• AWS: EC2

IaaS

Deployment models
• Public cloud
• Community cloud
• Hybrid cloud
• Private cloud

Cloud Computing Challenges

• Privacy
• Availability
• Reliability: Data centers and backup
• Security
• Downtime
• Access
• Dependency

References

• Cisco Cloud:
http://www.canscouncil.net/presentations
• Wikipedia:
• http://en.wikipedia.org/wiki/Cloud_computin
g
• Nomadesk:
http://blog.nomadesk.com/companyupdates/ne
ws/why-students-can-use-cloud-computing/

Cloud computing

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