Cloud Computing Key Terms

Cloud

A cloud refers to a distinct IT environment that is designed for the purpose of remotely provisioning scalable and measured IT resources. The term originated as a metaphor for the Internet which is, in essence, a network of networks providing remote access to a set of decentralized IT resources.

IT resource

An IT resource is a physical or virtual IT-related artifact that can be either software-based, such as a virtual server or a custom software program, or hardware-based, such as a physical server or a network device.

Examples :

Physical server, virtual server, software program, service, storage device, network device.

On-premise

As a distinct and remotely accessible environment, a cloud represents an option for the deployment of IT resources. An IT resource that is hosted in a conventional IT enterprise within an organizational boundary

An on-premise IT resource can access and interact with a cloud-based IT resource.
An on-premise IT resource can be moved to a cloud, thereby changing it to a cloud-based IT resource.
Redundant deployments of an IT resource can exit in both on-premise and cloud-based environment.

Scaling

Scaling, from an IT resource perspective, represents the ability of the IT resource to handle increased or decreased usage demands.

Horizontal Scaling - scaling out and scaling in

Vertical Scaling - scaling up and scaling down

Horizontal Scaling

The allocating or releasing of IT resources that are of the same type is referred to as horizontal scaling. The horizontal allocation of resource is referred to as scaling out and the horizontal releasing of resources is referred to as scaling in. Horizontal scaling in a common form of scaling within cloud environment.

Vertical Scaling

When an existing IT resource is replaced by another with higher or lower capacity, vertical scaling is considered to have occurred. Vertical scaling is less common in cloud environment due to the downtime required while the replacement is taking place.

Cloud Service

Although a cloud is a remotely accessible environment, not all IT resource residing within a cloud can be made available for remote access. For example, a database or a physical server deployed within a cloud may only be accessible by other IT resources that are within the same cloud.
A cloud service is any IT resource that is made remotely accessible via a cloud. Unlikely other IT fields that fall under the service technology umbrella-such as service—- such as service-oriented architecture—the term “service” within the context of cloud computing is especially broad.

Cloud service consumer

The cloud service consumer is a temporary runtime role assumed by a software program when it accesses a cloud service.

Example : software program, service, laptop, mobile device, laptop, workstation.

Goals and benefits

1. Reduced investments and proportional costs.2. Increased scalability.3. Increased availability and reliability.

On- demand access to pay-as-you-go computing resources on a short-term basis (such as processors by the hour), and the ability to release these computing resources when they are no longer needed.

The perception of having unlimited computing resources that are available on demand, thereby reducing the need to prepare for provisioning.

The ability to add or remove It resources at a fine-grained level, such as modifying available storage disk space by single gigabyte increments.

Abstraction of the infrastructure so applications are not locked into devices or locations and can be easily moved if needed.

Risks and Challenges

Several of the most critical cloud computing challenges pertaining mostly to cloud consumers that use IT resources located in public clouds are presented and examined.

1. increased security vulnerabilities2. Reduced operational governance control3. Limited Portability Between Cloud Providers4. Multi-Regional compliance and legal issues

Cloud resource administrator

A cloud administrator is the person or organization responsible for administering a cloud a cloud service.

Cloud roles:

Cloud consumers

Cloud providers

Cloud auditor

Cloud broker

Cloud carrier

Cloud characteristics

1. On-demand usage2. Ubiquitous access3. Elasticity4. Measured usage5. Resiliency

Cloud delivery models

Infrastructure as a service

The IaaS delivery model represents a self-contained IT environment comprised of infrastructure-centric IT resources that can be accessed and managed via a cloud service-based interfaces and tools.
This environment can include hardware, network, connectivity, operating systems, and other “raw” IT resources.

Platform as a service

The PaaS delivery model represents a pre-defined “ready-to-use” environment typically comprised of already deployed and configured IT resources.

Software as a service

A software program positioned as a shared cloud service and made available as a “product” or generic utility represents the typical profile of a SaaS offering.
Combining cloud delivery models
The three base cloud delivery models comprise a natural provisioning hierarchy, allowing for opportunities for the combined application of the models to be explored.

Cloud deployment models

Public cloud

Community cloud

Private cloud

Hybrid cloud

Business driver

Capacity planning

Cost reduction

Organizational agility

Technology innovation

Clustering
Virtualization#