Simplifying NIST defined Cloud characteristics

Cloud Characteristics

There are several variations of the cloud definition and the characteristics associated with cloud computing. Let us cover the basics and make it easy to understand the essential characteristics and why they are important.

On-Demand availability of services

This characteristic is essential in a cloud service In traditional IT environments, there is no on-demand availability of services; typically one has to go through a long procurement process to get an application or an IT service. As an example of Infrastructure as a Service (IaaS), the cloud provides compute, network, storage, and security services on demand. As a result, users that require infrastructure services can order them and get them at the click of a button, rather than wait for a lengthy procurement process to complete before the capacity of a particular service is delivered. In other words, cloud providers have systems that can provide compute and other resources on demand to the users without any hassles.

Standardization and automation in a cloud computing environment enable agility and on-demand provisioning of resources. In fact, one can use a credit card to purchase compute capacity and have a virtual instance running in the cloud in a matter of minutes. Thus, cloud computing enables immediate access to resources when demanded by the users or applications.

Network Access

The cloud services are available on the Internet and can be accessed through multiple modes of connectivity including dedicated connections. The connectivity is based on open standards. Thus, cloud computing—just like the Internet—crosses national boundaries and provides services to the world.

Pooling of resources

The cloud provider creates a pool of compute capacity that is offered to multiple customers or tenants. The cloud provider makes an upfront investment in creating a cloud service and has ready capacity to offer to customers.

The pooled resources allow multiple customers to leverage the service and use the shared infrastructure for their requirements. The consumer may not have exact knowledge of the location of the service being offered, though they may choose the continent, country, or approximate location from where services are offered. The cloud provider has automations and dynamic placement engines in place that ensure that the capacity is shared across customers and that they get sufficient resources to run their applications.

The cloud provider thus acts as an owner of the cloud computing resources that are rented out to multiple customers, who use it in a shared model. The concept is similar to the way a taxi or a bus service works, wherein a bus or taxi is used by multiple tenants but it is owned by someone else.

The cloud provider ensures security and confidentiality of customer information and has systems in place to ensure one customer’s resources or data is not accessed by the other customers hosted on the same physical resources. Thus, network bandwidth, compute cycles, memory, and storage are resources in IaaS that are offered as a shared pool of resources to customers.

Elasticity

The cloud provider builds the service with scalability in mind. As a result, all aspects of the cloud service should be elastic and scalable.

As the usage of an application grows, the customers can order more capacity from the cloud provider in an automated fashion. Applications that require a rapid scale up or down in capacity are ideally suited to cloud environments since the cloud has vast amounts of capacity available on demand.

However, it does not mean that the cloud has infinite capacity. The elasticity of the cloud is much higher than a traditional IT environment of an enterprise as the cloud is architected to be scalable and the cloud provider keeps enough capacity to meet the needs of its customers. Also, since it is a shared infrastructure, the peaks and troughs of usage by multiple tenants, particularly over wide geographic ranges, ensure that the infrastructure is used more optimally than a dedicated one.

Pay Per Use

The cloud providers provide metering and billing so that the customers can be billed on a pay-per-use model. The customers use the capacity and are billed for the usage. This is analogous to the way telecom companies bill their customers by the number and duration of calls made; at the end of the month, a bill is generated detailing the calls, duration, and the cost of each item. The cloud operates in a similar way where transparent billing is available based on various types of plans and customers can pay using various methods including a credit card.

Shared Management

Since the cloud provider offers a standardized mass market service, there are aspects of the service that are self-managed. The basic monitoring, provisioning, replication, and availability of service are managed by the cloud provider using advanced technologies.

The economies of scale and automation are realized in the cloud world since now it is possible for the cloud provider to provide these advanced technologies for self-managed infrastructure in a standardized fashion. The cloud provider provides basic management features and functions through automated means and the layers above are to be managed by the customer. As an example, the IaaS provider provides the virtualization platform and shared network and storage as a managed service, but the operating system and the applications run on this infrastructure by the customer have to be managed by the customer. Thus, the management of the core cloud platform is done by the provider and the other components are managed by the customers themselves.

The cloud provides cost savings and agility to enterprises and consumers so that they can focus on their core business and enjoy the benefits of a highly available and scalable service.