Infrastructure Update: Move Legacy Applications to the Cloud

Costs are being closely watched in every division in an enterprise, but particularly in the IT department - controlling IT spending is an objective in nearly every organization. There are also corporations where what has been traditionally described as IT is now the basis of the business. So limiting costs will reduce the cost of operations. (Think of Amazon, Google, PayPal,, etc.) This transition point in IT is being driven by the appearance of clouds, whether dark or with a silver lining. The choice for IT administrators tends to fall into a.) use an internal, private cloud, b.) use an external, public cloud, or c.) use a hybrid cloud consisting of both private and public clouds.

It is readily apparent that running applications in the cloud reduces costs by providing IT customers with self-service provisioning. The paradigm shift in retailing that has significantly reduced staffing and customer service representatives is now reaching IT. Increasingly the individual, whether a staff member in a corporation or an entrepreneur starting a new Web based business, can self-select the computing resources required for an application. Businesses and governments are moving into the cloud.

Furthermore, the cloud has turned the economics of backup and recovery on its head. In the public cloud, the cloud vendors maintain backups for virtual servers. It would be just as easy for administrators of private clouds to maintain standby backups of the applications at significantly lower cost than the traditional duplicate architecture used in many DR schemes.

(I’ll admit that the vision I embrace here doesn’t exist without glitches but the hurdles are technical and will be overcome. The ODCA is working to develop solutions to address these issues.)

The cloud is great for new and dynamic applications. Developers can work in test environments in the cloud, shortening development cycles dramatically.  Because a virtual server in the cloud is dynamic in and of itself, testing performance parameters of applications - both new apps and upgrades - can result in previously unavailable accuracy in provisioning the eventual production server. Costs and time associated with application development can be significantly reduced.

Hybrid Clouds, discussed here by Billy Cox add to the mix by offering an alternative to building the entire infrastructure in-house. Many components of an application can be hosted outside the walls when the application does not use proprietary data.

The old consultant adage is "You want it right? You want it soon? You want it cheap? Choose only two." The cloud is allowing some managers to choose all three.

This is great news for those developing and deploying new applications. Those legacy applications running in Linux* or Windows* servers can likely take advantage of cloud economics. Migration to the cloud from Windows or Linux can be done carefully and efficiently using automated P2V tools from various vendors.

But what about all those applications running on AIX or Solaris* platforms, how can they take advantage of the economies of the cloud? This may require a complex migration as most clouds are built on servers from various manufacturers that are running on Intel Xeon processors. With this we’re back to the old RISC to Xeon processor migration issues (i.e. big endian Power* and SPARC* processors and little endian Xeon processors).

The first step in planning to move an application running on expensive legacy servers is to look at my migration spectrum. What sort of application is being targeted to run in the cloud? Where does it fit on the spectrum? Determining this will give you a 10,000 foot view of the effort that will be required.

Most applications running on expensive legacy servers are running in partitions. I suppose some of you were thinking, how does an application on a Power 5 server fit into a server carved out of the cloud? Isn’t that something like trying to fit the size 23 feet of Shaquille O’Neal into size 10.5 sneakers? But the applications are usually smaller than the entire server because they are running in a partition, or the utilization rate is near the data center norm of 15%.   The best news is that the performance difference between modern Intel Xeon processors and Power 5 servers is such that an application running in the legacy server can easily fit in a server carved out of the cloud.

Please share some of your experiences in migrating legacy UNIX* applications into the cloud. Did you find it difficult?