Introduction to Cloud Computing

Cloud computing is the on-demand delivery of IT resources over the Internet with pay-as-you-go pricing.

Information and data processing can be done more efficiently on large farms of computing and storage systems accessible via the Internet.

Grid computing is a collection of computer resources from multiple locations to reach a common goal, mainly for scientific computing.

Utility computing is a service model where providers offer computing resources on demand and charge based on usage.

On-demand, scalable, elastic services with metered usage and resource sharing.

The ability to dynamically acquire computing resources on demand to support variable workloads.

Lower provider costs due to resource multiplexing are passed on to users.

Data is stored in the cloud, appearing location-independent to users.

Service providers handle maintenance and security for higher efficiency.

CPU cycles, storage, and network bandwidth shared among users.

Multiple applications share systems and their peak demands do not align, allowing higher utilisation.

They support data-intensive applications.

Data sharing facilitates global collaborative work.

Users no longer need to buy or maintain private computing infrastructure.

Users pay only for the resources they consume.

The ability to scale workloads up or down quickly.

Users work in familiar, virtualised environments.

A cloud infrastructure available to the general public and owned by a service provider.

A cloud infrastructure used exclusively by one organisation.

A combination of two or more cloud types enabling data and application portability.

A cloud infrastructure shared by organisations with common concerns.

It efficiently exploits advances in software, networking, storage, and processors.

Its adoption by industries, finance, and government creates huge economic impact.

A single cloud often runs homogeneous resources within one administrative domain.

Service failure or downtime from the provider.

Users rely on providers to protect sensitive data, raising auditability issues.

Different providers use different data organisation and interfaces, limiting mobility.

Many cloud applications are highly data-intensive.

Resource sharing among multiple users.

Large data centres must handle varied and complex workloads.

Sensitive applications require strong protection from breaches.

Infrastructure-as-a-Service provides compute resources, VMs, storage, and networking with user control over OS and apps.

Operating systems, storage, deployed applications, and some networking components.

Server hosting, storage, virtual instances, load balancing, bandwidth provisioning.

Platform-as-a-Service lets users deploy applications using provider-supported languages and tools.

Deployed applications and some hosting environment configurations.

Underlying infrastructure such as servers, OS, networks, and storage.

When applications must be portable, use proprietary languages, or require customised hardware/software.

Google App Engine and Windows Azure.

Like taking a taxi—you provide the destination, and the provider handles the route and vehicle.

Software-as-a-Service provides complete applications managed by the service provider.

They do not manage infrastructure or application capabilities.

Workflow management, CRM, communication tools, financial management, and more.

For real-time applications or when data cannot be hosted externally.

Gmail and Salesforce.

Virtualisation, provisioning, QoS, billing, support, and backups.

Authentication, intrusion detection, cryptography, access control, and firewalls.

Customer support, subscriptions, BI, reporting, and personalisation.

Data management and development.

Users relinquish control to third-party services.

Data is stored across multiple organisations and locations.

Multiple services interacting can lead to unauthorised access, corruption, failures, or downtime.

Systems span multiple organisations, crossing security boundaries and complicating responsibility.

Unauthorised access and data dissemination increase risks.

Providers store massive amounts of sensitive personal information globally.

Some cultures value privacy highly, while others prioritise community, creating mixed attitudes.

Malicious attacks and infrastructure failures like power outages.