4. Cloud computing is all the rage. "It's
become the phrase du jour,“
-Gartner (senior analyst Ben
Pring)
5. COMPARISON
Cloud computing shares characteristics with:
• Autonomic computing — Computer systems capable of self-management.
• Client–server model — Client–server computing refers broadly to any distributed
application that distinguishes between service providers (servers) and service
requesters (clients).
• Grid computing — "A form of distributed and parallel computing, whereby a
'super and virtual computer' is composed of a cluster of networked, loosely
coupled computers acting in concert to perform very large tasks."
• Mainframe computer — Powerful computers used mainly by large organizations
for critical applications, typically bulk data processing such as census, industry and
consumer statistics, police and secret intelligence services, enterprise resource
planning, and financial transaction processing.
• Utility computing — The "packaging of computing resources, such as computation
and storage, as a metered service similar to a traditional public utility, such as
electricity."
• Peer-to-peer — Distributed architecture without the need for central coordination,
with participants being at the same time both suppliers and consumers of
resources (in contrast to the traditional client–server model).
6. Characteristics
• Agility improves with users' ability to re-provision technological infrastructure resources.
• Application programming interface (API) accessibility to software that enables machines to interact
with cloud software in the same way the user interface facilitates interaction between humans and
computers. Cloud computing systems typically use REST-based APIs.
• Cost is claimed to be reduced and in a public cloud delivery model capital expenditure is converted
to operational expenditure. This is purported to lower barriers to entry, as infrastructure is typically
provided by a third-party and does not need to be purchased for one-time or infrequent intensive
computing tasks. Pricing on a utility computing basis is fine-grained with usage-based options and
fewer IT skills are required for implementation .
• Device and location independence enable users to access systems using a web browser regardless
of their location or what device they are using (e.g., PC, mobile phone). As infrastructure is off-site
(typically provided by a third-party) and accessed via the Internet, users can connect from
anywhere.
• Virtualization technology allows servers and storage devices to be shared and utilization be
increased. Applications can be easily migrated from one physical server to another.
• Multi-tenancy enables sharing of resources and costs across a large pool of users thus allowing for:
– Centralization of infrastructure in locations with lower costs (such as real estate, electricity, etc.)
– Peak-load capacity increases (users need not engineer for highest possible load-levels)
– Utilization and efficiency improvements for system
7. Continued… (2)
• Reliability is improved if multiple redundant sites are used, which makes well-designed cloud
computing suitable for business continuity and disaster recovery.
• Scalability and Elasticity via dynamic ("on-demand") provisioning of resources on a fine-
grained, self-service basis near real-time, without users having to engineer for peak loads.
• Performance is monitored, and consistent and loosely coupled architectures are constructed
using web services as the system interface.
• Security could improve due to centralization of data, increased security-focused
resources, etc., but concerns can persist about loss of control over certain sensitive data, and
the lack of security for stored kernels. Security is often as good as or better than other
traditional systems, in part because providers are able to devote resources to solving security
issues that many customers cannot afford. However, the complexity of security is greatly
increased when data is distributed over a wider area or greater number of devices and in
multi-tenant systems that are being shared by unrelated users. In addition, user access to
security audit logs may be difficult or impossible. Private cloud installations are in part
motivated by users' desire to retain control over the infrastructure and avoid losing control of
information security.
• Maintenance of cloud computing applications is easier, because they do not need to be
installed on each user's computer and can be accessed from different places.
12. • Hybrid cloud: It is a composition of two or more clouds (private,
community or public) that remain unique entities but are bound
together, offering the benefits of multiple deployment models.
• Private cloud: Private cloud is cloud infrastructure operated solely
for a single organization, whether managed internally or by a
third-party and hosted internally or externally.
15. What's In The Cloud OS?
• An operating system that spans & controls a set
of connected servers:
– Abstract execution environment
– Shared file system
– Resource allocation
– Programming environments
• And more: Utility computing
– 24/7 operation
– Pay for what you use
– Simpler, transparent administration
16. What Is Windows Azure?
• It is an operating system for the cloud
• It is designed for utility computing
• It provides facilities to:
– Write your apps (developer experience)
– Host your apps (compute)
– Manage your apps (service management)
– Store your data (storage)
17. Storage
S c a l a b l e & A va i l a b l e
• Simple, essential storage abstractions:
– Large items of data: Blobs, file streams, …
– Service state: Simple tables, caches, …
– Service communication: Queues, locks, …
• With an emphasis on:
– Massive scale, availability and durability
– Geo-location and geo-replication
• This is not a relational database in the cloud
• cloud services running on Windows Azure will have access
to co-located relational database in the cloud
– There are multiple target scenarios
18. Putting It All Together
• Example:
n m
LB
Web Role Worker Role
Cloud Storage
19. Windows Azure Is
• Designed to encourage best practices
– Stateless compute + durable storage
– Co-location of computation and data
– Queues for asynchronous processing
• An open platform
– Connect outbound to any server
– Open protocols and APIs on all components
20. Amazon EC2
• EC2is a central part of Amazon.com's cloud
computing platform, Amazon Web
Services (AWS).
• EC2 allows users to rent virtual computers on
which to run their own computer applications.
• A user can create, launch, and terminate server
instances as needed, paying by the hour for
active servers, hence the term "elastic". EC2
provides users with control over the geographical
location of instances that allows for latency
optimization and high levels of redundancy
21. Elastic Compute Unit
(ECU)
• The Elastic Compute Unit (ECU) was introduced by
Amazon EC2 as an abstraction of computer resources.
• Amazon’s Definition of ECU notes “We use several
benchmarks and tests to manage the consistency and
predictability of the performance of an EC2 Compute
Unit.
• One EC2 Compute Unit provides the equivalent CPU
capacity of a 1.0-1.2 GHz 2007 Opteron or
2007 Xeon processor.
• It is also the equivalent to an early-2006 1.7 GHz Xeon
processor referenced in our original documentation”
22. Amazon S3
• Amazon S3 (Simple Storage Service) is an online
storage web service offered by Amazon Web
Services. Amazon S3 provides storage through
web services interfaces.
• S3 is designed to provide 99.999999999%
durability and 99.99% availability of objects over
a given year.
• S3 stores arbitrary objects (computer files) up to
5 terabytes in size, each accompanied by up to 2
kilobytes of metadata.
23. Operating systems:
When it launched in August 2006, the EC2 service
offered Linux and later Sun Microsystems' Open
Solaris and Solaris Express Community Edition.
In October 2008, EC2 added the Windows Server
2003 and Windows Server 2008 operating systems
to the list of available operating systems.
As of December 2010 it has also been reported to
run FreeBSD;
in March 2011, NetBSD AMIs became available.
24. Persistent Storage:
An EC2 instance may be launched with a choice of two
types of storage for its boot disk or root device.
The first option is a local "instance-store" disk as a root
device (originally the only choice). The second option is to
use an EBS volume as a root device
EBS volumes provide persistent storage independent of the
lifetime of the EC2 instance, and act much like hard drives
on a real server.
Users can set up and manage storage volumes of sizes
from 1GB to 1TB.
EBS volumes can be attached or detached from instances
while they are running, and moved from one instance to
another.
25. Elastic IP Addresses:
* Amazon's Elastic IP Address feature is similar to static
IP address in traditional data centers, with one key
difference. A user can programmatically map an
Elastic IP Address to any virtual machine instance
without a network administrator's help and without
having to wait for DNS to propagate the new binding.
* In this sense an Elastic IP Address belongs to the
account and not to a virtual machine instance
* It exists until it is explicitly removed. It remains
associated with the account, even while it is
associated with no instance.
26. Amazon Cloud Watch:
Amazon Cloud Watch is a Web service that
provides real-time monitoring to Amazon's EC2
customers on their resource utilization such as
CPU, disk and network.
Cloud watch does not provide any memory, disk
space, or load average metrics.
An Amazon engineer has stated that this is due
to the requirement to install software in the VM -
something they wish to avoid.
27. Automated Scaling:
Amazon's Auto
Scaling feature of
EC2 allows it to
automatically adapt
computing capacity
to site traffic
28. ISSUES ON CLOUD
Privacy
• The cloud model has been criticized by privacy advocates for the greater ease in which
the companies hosting the cloud services control, thus, can monitor at will, lawfully or
unlawfully, the communication and data stored between the user and the host company
• Using a cloud service provider (CSP) can complicate privacy of data because of the
extent to which virtualization for cloud processing (virtual machines) and cloud storage
are used to implement cloud service.
• Cloud computing poses privacy concerns because the service provider at any point in
time, may access the data that is on the cloud. They could accidentally or deliberately
alter or even delete some info.
29.
30. Open source:
Open-source software has provided the
foundation for many cloud computing
implementations, one prominent example
being the Hadoop framework
Open standards:
Most cloud providers expose APIs that are
typically well-documented (often under a
Creative Commons license) but also unique to
their implementation and thus not
interoperable
31. Security:
• As cloud computing is achieving increased popularity, concerns are being voiced about
the security issues introduced through adoption of this new model. The effectiveness and
efficiency of traditional protection mechanisms are being reconsidered as the
characteristics of this innovative deployment model can differ widely from those of
traditional architectures.
• An alternative perspective on the topic of cloud security is that this is but another,
although quite broad, case of "applied security" and that similar security principles that
apply in shared multi-user mainframe security models apply with cloud security.
• The relative security of cloud computing services is a contentious issue that may be
delaying its adoption.
32. Sustainability:
• Although cloud computing is often assumed to be a form of "green computing", there is no
published study to substantiate this assumption. Citing the servers affects the environmental
effects of cloud computing.
• In areas where climate favors natural cooling and renewable electricity is readily available, the
environmental effects will be more moderate. (The same holds true for "traditional" data
centers.)
• Countries with favorable conditions, such as Finland, Sweden and Switzerland, are trying to
attract cloud computing data centers.
• Energy efficiency in cloud computing can result from energy-aware scheduling and server
consolidation.
• However, in the case of distributed clouds over data centers with different source of energies
including renewable source of energies, a small compromise on energy consumption reduction
could result in high carbon footprint reduction.
33. Abuse:
• As with privately purchased hardware,
customers can purchase the services of
cloud computing for nefarious purposes.
• This includes password cracking and
launching attacks using the purchased
services.
• In 2009, a banking Trojan illegally used the
popular Amazon service as a command
and control channel that issued software
updates and malicious instructions to PCs
that were infected by the malware