Businesses discover that cloud computing isn't magic

Businesses are now (just now, after more than a decade of cloud computing) discovering that cloud computing is not magic. That it doesn't make their computing cheap. That it doesn't solve their problems.

Some folks have already pointed this out. Looking back, it seems obvious: If all you have done is move your web-based system into cloud-based servers, why would things change? But they miss an important point.

Cloud computing is a form of computing, different from web-based applications and different from desktop applications. (And different from mainframe batch processing of transactions.)

A cloud-based system, to be efficient, must be designed for cloud computing. This means small independent services reading and writing to databases or other services, and everything coordinated through message queues. (If you know what those terms mean, then you understand cloud computing.)

Moving a web-based application into the cloud, unchanged, makes little sense. Or as much sense as moving a desktop-based application (remember those?) such as Word or Excel into the web, unchanged.

So why use cloud computing?

Cloud computing's strengths are redundancy, reliability, and variable power. Redundancy in that a properly designed cloud computing system consists of multiple services, each of which can be hosted on multiple (as in more than one per service) servers. If your system contains a service to perform address validations, that service could be running on one, two or seven different servers. Each instance does the same thing: examine a mailing address and determine the canonical form for that address.

The other components in your system, when they need to validate or normalize an address, issue a request to the validation service. They don't care which server handles the request.

Cloud systems are reliable because of this redundancy. A traditional web-based service would have one address validation server. If that server is unavailable, the service is unavailable for the entire system. Such a failure can lead to the entire system being unavailable.

Cloud systems have variable power. They can create additional instances of any of the services (including our example address validation service) to handle a heavy workload. Traditional web services, with only one server, can see slow response times when that server is overwhelmed with requests. (Sometimes a traditional web system would have more than one server for a service, but the number of servers is fixed and adding a server is a lengthy process. The result is the same: the allocated server or servers are overwhelmed and response time increases.)

Cloud services eliminate this problem by instantiating servers (and their services) as needed. When the address validation server is overwhelmed, the cloud management software detects it and "spins up" more instances. Good cloud management software works in the other direction too, shutting down idle instances.

Those are the advantages of cloud systems. But none of them are free; they all require that you build your system for the cloud. That takes effort.