2. CLOUD COMPUTING
Cloud computing is the on-demand availability of computer system resources, especially data storage (cloud storage) and computing power, without direct active
management by the user. The term is generally used to describe data centers available to many users over the Internet. Large clouds, predominant today, often have
functions distributed over multiple locations from central servers. If the connection to the user is relatively close, it may be designated an edge server.
Clouds may be limited to a single organization (enterprise clouds), or be available to multiple organizations (public cloud).
Cloud computing relies on sharing of resources to achieve coherence and economies of scale.
Advocates of public and hybrid clouds note that cloud computing allows companies to avoid or minimize up-front IT infrastructure costs. Proponents also claim that
cloud computing allows enterprises to get their applications up and running faster, with improved manageability and less maintenance, and that it enables IT teams to
more rapidly adjust resources to meet fluctuating and unpredictable demand, providing the burst computing capability: high computing power at certain periods of peak
demand.
How do you access cloud computing?
Cloud computing is accessed through an application (e.g., Dropbox app) on your computer, smartphone, or tablet or a website that accesses the cloud through
your browser.
3. Examples of cloud services
If you have spent any time on the Internet or use devices connected to the Internet, you likely have used cloud computing in some form. Below are some common
examples of cloud computing you have likely heard of or used.
• Adobe Creative Cloud is a cloud-based Software as a service offering from Adobe.
• AWS (Amazon Web Services) and Amazon EC2 - Amazon.com provides a variety of different cloud computing services
• Dashlane - Online password service to synchronize and manage passwords between all devices.
• Google App Engine - A service that provides users the ability to create scalable web services that use Google's resources.
• Google Calendar - A way to organize your schedule, synchronize, and share events with your friends.
• Google DoCs - A fantastic free solution from Google that allows you to open Microsoft Office documents as well as share them with other users with Internet
access.
• Microsoft OneDrive - Formerly known as SkyDrive, OneDrive is an online storage service for Windows 8 and Windows 10 users to store Windows related files,
Office documents, and other files.
• Nextcloud - Open-source software that allows you to run a personal cloud server, forked from the OwnCloud project.
• Online backup - There are several online backup services to store your important information offsite in the cloud. For example, Mozy and Dropbox are two good
examples of cloud storage and online storage or internet storage backup solutions that store information in the cloud.
• Oracle public cloud - Oracle cloud service for small and large businesses.
• OwnCloud - Open-source software that enables you to run a personal cloud file storage service.
• Windows Azure - A cloud computing solution by Microsoft that allows companies to develop and run services from their cloud.
4. Basic Concepts
There are certain services and models working behind the scene making the cloud computing feasible and accessible to end users. Following are the working
models for cloud computing:
Service Models
Deployment Models
Service Models
Service Models are the reference models on which the cloud computing is based. These can be categorized into three basic service models as listed below:
Software as a Service (SaaS)-End users
Platform as a Service (PaaS)- Application Developers
Infrastructures as a Service(IaaS)- Network Architects
5. Software as a Service (SaaS)-end users
Software as a Service (SaaS) is a model for the distribution of software where customers access software over the Internet. In SaaS, a service provider hosts the
application at its data center and a customer accesses it via a standard web browser.
There are a few major characteristics that apply to most SaaS vendors:
• Updates are applied automatically without customer intervention
• The service is purchased on a subscription basis
• No hardware is required to be installed by the customer
SaaS is also known as hosted software or on-demand software.
Examples of SaaS include Google Apps, Dropbox, Salesforce, Cisco WebEx, Concur, GoToMeeting.
Platform as a service (PaaS)- Application Developers
Platform as a service (PaaS) is a concept that describes a computing platform that is rented or delivered as an integrated solution, solution stack or service through an
Internet connection.
Some of the major characteristics of a PaaS offering include:
• Web based user interface
• Services to develop, test, deploy, host and maintain applications
• Multi-tenant architecture
• Scalability, load balancing and failover
Examples of PaaS include AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com, Google App Engine, Apache Stratos, OpenShift.
6. Infrastructures as a Service (IaaS)- Network Architects
Infrastructure as a Service (IaaS) is the practice of delivering a full compute stack — including servers, storage, networking and operating software — as an abstract,
virtualized construct.
Like other service-based offerings (Software as a Service, Platform as a Service), IaaS allows users to consume only what they need while offloading complex and
expensive management tasks to their provider.
Characteristics of IaaS systems include:
• Automated administrative tasks.
• Dynamic scaling.
• Platform virtualization technology.
• GUI and API-based access.
• Internet connectivity.
Infrastructure as a service (IaaS) is also known as hardware as a service (HaaS).
7. Deployment Models
Deployment models define the type of access to the cloud, i.e., how the cloud is located? Cloud can have any of the three type of access:
Public Cloud
Private Cloud
Hybrid Cloud
Public Cloud
The public cloud allows systems and services to be easily accessible to the general public. Public cloud may be less secure because of its openness, e.g., e-mail.
Private Cloud
The private cloud allows systems and services to be accessible within an organization. It offers increased security because of its private nature.
Hybrid Cloud
The hybrid cloud is a mixture of public and private cloud. However, the critical activities are performed using private cloud while the non-critical activities are
performed using public cloud.
8. Advantages Of Cloud Computing
Easy Implementation: Cloud hosting allows business to retain the same applications and business processes without having to deal with the backend technicalities.
Readily manageable by the Internet, a cloud infrastructure can be accessed by enterprises easily and quickly.
Accessibility: Access your data anywhere, anytime. An Internet cloud infrastructure maximizes enterprise productivity and efficiency by ensuring your application
is always accessible. This allows for easy collaboration and sharing among users in multiple locations.
No hardware required: Since everything will be hosted in the cloud, a physical storage center is no longer needed. However, a backup could be worth looking into
in the event of a disaster that could leave your company's productivity stagnant.
Cost per head: Overhead technology costs are kept at a minimum with cloud hosting services, enabling businesses to use the extra time and resources for
improving the company infrastructure.
Flexibility for growth: The cloud is easily scalable so companies can add or subtract resources based on their needs. As companies grow, their system will grow
with them.
Efficient recovery: Cloud computing delivers faster and more accurate retrievals of applications and data. With less downtime, it is the most efficient recovery
plan.
9. Disadvantages Of Cloud Computing
No longer in control: When moving services to the cloud, you are handing over your data and information. For companies who have an in-house IT staff, they will be
unable to handle issues on their own. However, Stratosphere Networks has a 24/7 live help desk that can rectify any problems immediately.
May not get all the features: Not all cloud services are the same. Some cloud providers tend to offer limited versions and enable the most popular features only, so
you may not receive every feature or customization you want. Before signing up, make sure you know what your cloud service provider offers.
Doesn't mean you should do away with servers: You may have fewer servers to handle which means less for your IT staff to handle, but that doesn't mean you can
let go of all your servers and staff. While it may seem costly to have data centers and a cloud infrastructure, redundancy is key for backup and recovery.
No Redundancy: A cloud server is not redundant nor is it backed up. As technology may fail here and there, avoid getting burned by purchasing a redundancy plan.
Although it is an extra cost, in most cases it will be well worth it.
Bandwidth issues: For ideal performance, clients have to plan accordingly and not pack large amounts of servers and storage devices into a small set of data centers.
