eCommerce in the Cloud

Chapter 6. Virtualization in the Cloud

Virtualization is a key enabler of cloud computing but it is not part of the cloud itself. As previously discussed, the cloud is defined by the following three attributes: elastic, on demand, and metered. Virtualization itself isn’t one of those three attributes but it does help to enable all three.

Note

Virtualization is a key enabler of the cloud but it is not the cloud itself.

Virtualization in its various forms enables the following:

Partitioning

Vendors don’t make any money if they can’t pack a lot of their customers on each physical server. Many vendors offer virtualized servers with as little as one physical hardware thread. There are typically two hardware threads per physical CPU core, 12 cores per processor, and two processors per physical host. That means a single commodity machine can be divided into 48 servers, each capable of being rented out to an individual or organization. Density is how vendors make their money.

Isolation

Given that partitioning hardware is required to make business models work, isolation is required to keep individual partitions from interfering with each other. You wouldn’t want a CPU-intensive workload like DNA sequencing to interfere with your application server’s ability to respond to HTTP requests. You can provision whole servers from many Infrastructure-as-a-Service vendors, just as you would secure fractional slices of physical servers.

Portability

Virtualization has tooling that makes it easy to ...