Many IT managers would love to move some of their applications out of the enterprise data center and into the cloud. It's a chance to eliminate a whole litany of costs and headaches: in capital equipment, in power and cooling, in administration and maintenance. Instead, just pay as you go for the computing power you need, and let someone else worry about managing the underlying infrastructure.

But moving from theory into practice is where things get complicated. It's true that a new web application built from scratch for the cloud as a standalone environment can be rolled out quickly and relatively easily. But for existing applications running in a traditional data center and integrating with a set of other systems, tools and processes, it's not nearly so simple.

What's really involved when moving an application from your enterprise data center to the cloud? Let's say you've decided on a particular cloud, and you've identified the application you want to run there - now what? You need to consider a range of issues which can potentially turn the migration into a complex engineering project.

Migrating to the Cloud
Today's cloud providers impose architectures that are very different from those of standard enterprise applications. As Bernard Golden explains in his in-depth look at cloud computing, difficulty in migration is holding back uptake, and there aren't yet any automated tools to smooth the way. The result is lots of manual configuring, complex engineering, and trial and error before the enterprise application is able to run in the cloud. A whole landscape of specifications for OS versions, storage, networks, integration with other applications and databases - all those configuration steps that normally happen behind the scenes - have to be mapped to a cloud environment that is probably very different from what your IT staff is used to. It's the type of project that can tie up a development team for weeks or even months.

Keeping Your Data Safe
When data moves to the cloud, it moves beyond the reach of tools and mechanisms put in place over the years to preserve its integrity. In an environment characterized by multi-tenancy and decoupling between hardware and applications, cloud users need to be vigilant and understand the risks. (For a good introduction to cloud security issues, see David Binnings' article, Top Five Cloud Computing Security Challenges.) In brief, you'll need to make sure that the cloud provider has a level of physical security and regulatory compliance that meets the needs of your business and the specific application (for example, those with public information vs. confidential vs. compliance-regulated). You'll also need to consider what additional measures might be necessary to protect against potential threats, including protecting data in transit as well as at rest. It may also be appropriate in some cases to keep the database within your data center and put the rest of the application outside in the cloud.

Managing Dual Environments
After you finally get your application running in the cloud, you'll find another big hurdle: how are you going to manage it? The cloud and the data center are currently two completely separate environments, each with its own set of system management tools, and no meaningful way to integrate the two. Accordingly, your IT staff will need to learn and use each cloud provider's management tools and policies, in addition to the ones they already have. They'll also have to give up some of the control and visibility into an application and its supporting infrastructure that's available in the data center, at least in current cloud environments. (More details about the challenges of managing enterprise applications in the cloud can be found in Peter Loh's article in Cloud Computing Journal.) And as the cloud provider makes changes to their underlying infrastructure (for example, patching a version of their OS), the cloud version of the application needs to be maintained to meet this new environment, so it becomes even more different from the local versions over time.

What if You Want to Change Clouds or Move Back to the Data Center?
All that effort was just for one cloud! What if another cloud provider comes along with lower prices or better service? Since you've invested all that time to set up the application for one cloud, you're going to be very reluctant to repeat all the development and integration work to meet the new provider's requirements. Many companies also wish they had the flexibility to use the cloud to develop and test a new application (leveraging the cloud's benefits in agility and low cost for early research/prototyping/development), before bringing it back to the data center to take advantage of the production set of data and their corporate processes and infrastructure. Today, it's not possible to move an application between different clouds or back to the data center easily, with a few mouse clicks. For many companies, the goal is to create a federated environment of their data center with one or more clouds, and to move applications and workloads wherever is most appropriate.

The cloud offers a great opportunity for enterprise applications, but it's important to understand the work required before embarking on a migration, and how the cloud environment will integrate with the existing data center. CloudSwitch has been working hard to address these issues. Stay tuned for further developments.

Read the original blog entry...