The growth of cloud computing leads to many new options, and there are some emerging architectural patterns to choose from when you deploy your cloud-based solutions.  The fundamental questions are, which cloud or clouds should make up your solution, and how can you mix and match the right clouds for the right jobs?

As enterprises stand up cloud applications, the basic decisions around the number and types of clouds to leverage comes down to a fundamental choice of fat clouds versus thin clouds.  Fat clouds are clouds that provide a dense array of features and services.  Thin clouds may focus on only one basic feature and a few services.

AWS clouds are an example of fat clouds, with services ranging from database-as-a-service to super computing, and all points inbetween.  IBM, HP, Rackspace, Salesforce.com, Microsoft, and a few more are the other big fat clouds in today’s market.

Examples of thin clouds are typically not brand name clouds that we hear about every day.  These are often small companies or startups that provide small but purpose-built cloud services, such as a database, or storage, or compute, or applications, or analytics, but (typically) not those items in combination.  There are hundreds and hundreds of these types of clouds out there, and several appear on my radar screen each week.  Many may actually run inside a fat cloud.

The concept of leveraging thin clouds is really nothing new.  We’ve been looking at remote application and utility services for years, typically RESTful web services that provide the resources to create mashups.  Mashups were all the rage several years ago, with the idea being that we can mix and match services from many different service providers (e.g., Google or Yahoo) to form and re-form applications.

When you define cloud solutions, you can choose to leverage a single fat cloud, such as AWS or Microsoft, which could provide you most of the services you’ll need for that solution, and you’ll deal with a single entity.  Or, perhaps you will mix and match thin clouds to find exactly the services you need, but at the cost of complexity, since you’ll have to deal with many clouds.

As depicted in Figure 1, choosing fat clouds means you’ll deal with fewer cloud providers, thus it’s easier to find and provision the services you’ll need.  Moreover, when in operational mode, minimizing the number of clouds means reducing the chances that an outage by any single cloud provider will take the entire application out-of-service.

Figure 1:  Thin cloud solution (above) leverages many purpose-built clouds to provide the right cloud services to an application from many providers.  Fat clouds (below) provide more services to the application, thus less clouds are required.

Also seen in Figure 1, the use of thin clouds means that many clouds are part of the solution, which increases complexity.  Moreover, the use of many clouds means that the application is more vulnerable to outages; there are just more links in the chain that could break.  Finally, the cloud providers are smaller and thus more likely to get acquired or go out of business.  Indeed, we saw a few small cloud companies go away last year.

However, the use of thin clouds means that you get exactly the services you need for your application.  You don’t settle for the database offering from a fat cloud provider that may not be an exact fit, but the storage services are, so you compromise.  Nor do you have to build something that you might find ready-made as-a-service from a smaller cloud provider, thus you waste less time in development and decrease associated risk and cost.

In other words, it’s you can build cloud-based business solutions that don’t leverage best-of-breed cloud services in order to reduce complexity, which translates to the use of a fat cloud solution.  Or, you can leverage the exact cloud services necessary to form the business solution by leveraging many thin clouds, but at the expense of added complexity and some added risk.  Thus the tradeoff.

The trend seems to be leaning toward the use of more thin clouds, as cloud computing continues to be the newest and best platform for many business applications.  Indeed, they may leverage a fat cloud as the primary host of the application, and augment the application with thin cloud services that are linked via APIs.  This all goes to the rise of multi-cloud solutions that seem to be the common direction of cloud computing these days, as many enterprises make the quick realization that they can’t find one single cloud that does everything, and therefore end up mixing and matching cloud services anyway.

I suspect we’ll see growth in the use of thin and fat clouds, as enterprises continue to figure all this out.  That said, while thin clouds may be a better solution, it’s been the pattern of enterprise IT in the past to move toward things that are simpler and less risky, aka, fat clouds.  I can’t help but think that we’re missing some thin cloud opportunities.