So many vendors are rushing to put the name “cloud” on their offering that one wonders who has something truly new to offer and who has changed nothing but the marketing. The concept is a few years old now, so we should be able to agree on a definition, so we can expose the charlatans.
The noun “cloud” suggests something which that is ever changing, hovering above the horizon, ready to be tapped into. That is an apt metaphor for cloud computing. That it is changing is true as well, since IT continually changes including the options for cloud computing.
For cloud computing, you can think of the definition coming from the infinite and malleable form of computing on a seemingly endless platform.
Adopting the cloud model means moving in-house servers and applications onto commodity hardware–either in part or in their entirety–running them on virtual machines and servers operating by third-party cloud providers, companies like Google, Amazon, or Microsoft. The word “commodity” means that the server manufacturers, and thus the data centers, have settled around the same PC-type x86 architecture which we recognize simply as the PC (personal computer), nothing special about that and bad news for hardware vendors. To say that it is a commodity suggests all of them are the same regardless of who is the manufacturer. While that might hurt the pride of those who designed and built these machines, such is the state of the business.
The cloud vendor divides the servers up into virtual machines. The means multiple operating systems are running within the operating system that powers the physical machine. The cloud provider has many customers. Each customer’s data and applications are kept separate from one another even though they might be located on the same computer. Mainframes have always operated this way. The idea is not new, but its adoption has grown so much that is the now the de facto standard for building out a new facility.
The cloud client gains access console access to the virtual machines, but maintenance of the server remains with the cloud service provider. Access to the servers varies by the customer needs and desires and constraints imposed by the cloud provider.
Cost and easy of operations is what drives the cloud’s appeal. Large companies can take advantage of the economies of school that the cloud vendors, operating tens of thousands of machines, can pass onto the client resulting in lower cost per transaction for the company. Small companies can forgo any capital expenditure at all and rent space on a server instead of buying one and setting it up themselves. It costs almost nothing to get started in the cloud. Costs are pegged to usage. It the startup company is successful, fees will increase with volume but presumably remain below the cost of an in-house infrastructure.
New networking standards are pushing networking functions, like routing and firewalls, onto commodity hardware virtualized servers as well. This is called network functions virtualization (NFV). The idea is to reduce the proliferation of proprietary appliances and bring some kind of standards to the interface. The standards writers say the command-line syntax should be the same whether the device is a router or a firewall, so that one does not need a different expert for each.
The hybrid cloud is the model under which many companies operate. You can run an application that is entirely in the cloud, like SalesForce.com, or you can run your own application on the cloud infrastructure in parts. The single sign-on servers and portal might run in your own facility, but the Siebel ERP system or the application database might be deployed at Amazon AWS. Where the application pieces are located depends on many factors like the cost savings of using a cloud for each application, access issues, company politics, and legacy systems too old to be moved at all.
This is our take on the definition. We hope we have made the idea more clear (Notice we did not say “less cloudy” as that pun would make the reader grown and we do not wish to destroy our credibility with flippancy.). To go beyond the general definition, we will present case studies on this blog to describe vendor offers and how companies are deploying applications to the cloud.