Cloud Computing has hit the main stage, solidly capturing the minds of both the technology and business communities. But while three distinct deployment models have emerged, it's far from certain which of them will go on to prosper. The three models are:
1. Renting raw hardware: compute processing, data storage and networking bandwidth.
2. Leveraging an integrated application development engine.
3. Ordering an application.
So in order to get a better sense of the prospects of each approach, let's take a closer look at key companies promoting them and the market forces shaping them.
Cloud Hardware Rental (Infrastructure as a Service)
Consuming compute and storage services is more involved than the term "rental" may indicate, but this first step transforms and focuses most businesses on their specific value, which isn't necessarily IT infrastructure.
The most well-known purveyor in this category is Amazon, but there are many other players as well, among them GoGrid, Layered Technologies, Joyent and Mosso/Rackspace.
The rental model provides one-to-one replacement of current enterprise infrastructure, except off-site and easily accessible. By choosing CPU type, memory amount and disk configurations of the lowest common denominator, customers of cloud hardware rental know exactly what they receive, can control the infrastructure at a fine-grain level and can easily compare pricing.
But it takes a certain skill set to load, operate and maintain applications in the cloud. Companies like RightScale and Elastra aim to streamline this process. And, unfortunately, Internet outages still occur, as evidenced by the Sprint-Cogent feud in late 2008, so everything may not always be at your fingertips.
Application Development Engines (Platform as a Service)
Sophisticated software offerings now easily tie together underlying hardware, touting "single-click" deployment and scaling of new application instances and machines. These engines also integrate common application components such as a data store, user authentication framework and cache. Some exist only in the cloud; others can be deployed privately.
In this category, Google offers AppEngine, Microsoft offers Azure, and Amazon has a suite of web services on top of basic server rental. Other software platforms that help speed up application development and deployment include 3Tera, Enomaly, and Eucalyptus, although all differ slightly in approach.
Compared with conventional application development, this strategy can slash development time, offer hundreds of readily available tools and services, and quickly scale. But developers still need to learn the platform, and such an approach may not support all programming languages, leading to concern over application portability.
Order an Application (Software as a Service)
Almost all companies use office supplies, but how many companies have their own paper and pulp processing facilities? The same question can be asked about installing, maintaining and operating enterprise applications. For most companies, ordering a cloud-based, software-as-a-service application lets them to get started in minutes, and provides plenty of readily accessible customization.
Saleforce.com is the poster child of this category. But other sizable applications come by way of Workday and Aravo, both of which recently touted their largest customer wins, Flextronics International and General Electric, respectively.
But for companies of a certain size and scale, the licensing model might not fit perfectly, and the quest for specific valued features, reports or integration may only be achievable through in-house deployment. Security has also been a big question around cloud and software-as-a-service applications, but as Alistair Croll points out, those questions deserve reexamination.
Placing Bets
So where are we headed next? Undoubtedly a combination of all three deployment models. Some companies, like data warehousing specialist Vertica, are taking the debate off the table by offering customers software, appliances or cloud services on top of Amazon's infrastructure.
But I believe that for companies providing new cloud offerings, the software-as-a-service or "order and application" approach will prove the most rewarding.
