Global cloud service providers are generally organized in a three-level structure:
CSP data centers: Individual physical data centers that house physical computers, storage, data center networking, environmental management equipment, and electrical power.
CSP availability zones: An availability zone (AZ) consists of two or more geographically local data centers. The AZ data centers will normally have independent sources of power and data connectivity.
CSP regions: A region typically consists of two or more availability zones. To ensure operational geographical redundancy, cloud-based solutions should deploy redundant infrastructures in two or more regions with mutual data backup capability.Read more: Cloud Service Provider Structure
The CSP operational process responsible for receiving, fulfilling, managing, monitoring, and metering customer services across all data centers, availability zones, and regions is referred to as cloud orchestration. The CSP software component responsible for orchestration is called the cloud operating system. Orchestration is accomplished through the use of hardware, software, and service application programming interfaces (APIs). Most cloud computing APIs use the Representational State Transfer (REST) communications protocol.
Cloud data centers typically have 10,000 or more servers on site, all devoted to running relatively few applications that are built with consistent infrastructure components (such as racks, hardware, OS, and networking). Cloud data centers are:
- Constructed for a different purpose
- Created at a different time than the traditional data center
- Built to a different scale
- Not constrained by the same limitations
- Performing different workloads than traditional data centers
Because of this design approach, the economics of a cloud data center are significantly different.
Key Drivers for Cloud Computing
A key driver for cloud computing is the shift from capital expenditure (CapEx), where organizations had to invest large sums of money, to operational expenditure (OpEx), which now enables companies to pay per use and avail themselves of pricing structures similar to monthly or quarterly leasing agreements. Additional drivers include (but are not limited to):
- Scalability: Users have access to many resources that scale based on user demand.
- Elasticity: The environment transparently manages a user’s resource utilization based on dynamically changing needs.
- Virtualization: Each user has a single view of the available resources, independent of how they are arranged in terms of physical devices.
- Cost: The pay-per-usage model allows an organization to pay only for the resources they need with basically no investment in the physical resources available in the cloud. There are no infrastructure maintenance or upgrade costs.
- Mobility: Users can access data and applications from around the globe.
- Collaboration: Users are starting to see the cloud as a way to work simultaneously on common data and information.
- Risk reduction: Users can use the cloud to test ideas and concepts before making major investments in technology.