cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction. The following essential features of cloud computing when identifying cloud services or discussing how a cloud service can be used. Where a service or solution does not meet all the following key characteristics, it is not true cloud computing! Both ISO/IEC 17788 and NIST cite the following as key characteristics of cloud computing.
On-demand self-service refers to cloud service provided that enables the provision of cloud resources on demand (i.e., whenever and wherever they are required). From a security perspective, this has introduced challenges to governing the use and provisioning of cloud-based services, which may violate organizational policies. By its nature, on-demand self-service does not require procurement, provisioning, or approval from finance, and as such can be provisioned by almost anyone with a credit card.
Self-service is also referred to as “self-provisioning,” the process where the customer or user can provision, manage, or operate the cloud services they are utilizing without interaction or assistance from the cloud provider or cloud provider personnel. It should also be true that all operations and functions should be available for the user to select or configure (based on the cloud service type) through completion of the user or system activities.
Broad Network Access
Cloud, by its nature, is “always on” and “always accessible,” offering users widespread access to resources, data, and other assets. Think convenience! Access what you want, when you need, from any location. Call in and get what you need, when it suits you! In theory, all you should require is internet access and relevant credentials and tokens, which will give you access to the resources. The interesting dynamic of recent times is the mobile device and smart device revolution, which is altering the way organizations fundamentally operate. These devices should be able to access the relevant resources; however, compatibility issues, the inability to apply security controls across all variations, and non-standardization of platforms and software systems have stemmed this somewhat.
Resource pooling is another advantage of cloud computing. Think of the days when if you needed more compute power, you would go to finance and procurement, and embark on a lengthy and often costly process to purchase more computing or compute capability. More often than not, these systems could utilize the resources between 80–90 percent for a few hours a week and reside at an average of 10–20 percent for the remainder. The cloud groups (pools) resources for use across the user landscape or multiple clients, which can then be scaled and adjusted to the user’s or client’s needs based on their workload or resource requirements. Cloud providers typically have large numbers of resources available, from hundreds to thousands of servers, network devices, applications, etc., which can accommodate large volumes of customers and can prioritize and facilitate appropriate resourcing for each client.
Rapid elasticity allows the user to obtain additional resources, storage, compute power, etc., as their need or workload requires. This is most often “transparent” to the user, with more resources added seamlessly as necessary. Because cloud services utilize the “pay per use” concept, you only pay for what you use, which is of particular benefit to seasonal or event-type businesses utilizing cloud services. The term plays on the analogy of a large elastic band, which you can pull and stretch depending on the materials that it will hold or secure. Think of a provider selling 50,000 tickets for a major sporting event or concert. Leading up to the ticket release date, little to no compute resources are needed; however, once the tickets go on sale, they may need to accommodate 50,000 users in the space of 30–40 minutes. In this case, rapid elasticity and cloud computing could be beneficial compared to traditional IT deployments, which would have to invest heavily using capital expenditure (CapEx) to have the ability to support such demand.
Cloud computing offers this unique and important component, which traditional IT deployments have struggled to provide: resource usage can be measured, controlled, reported, and alerted upon, which results in multiple benefits and overall transparency between the provider and client. In the same way that you may have a metered electricity service or a mobile phone that you reload with credit, these services allow you to control and be aware of costs. Essentially, you pay for what you use and have the ability to get an itemized bill or breakdown of usage. A key benefit for many proactive organizations is the ability to charge departments or business units for their use of services, thus allowing IT and finance to quantify exact usage and costs per department or by business function—something that was incredibly difficult to achieve in traditional IT environments.