The public cloud has many definitions, but at its core it is any approach where IT is not on your premises and users connect via the network to an infrastructure you do not own. You can further break down the cloud into three categories:
Software as a Service (SaaS) – This model is as old as networking technology. An application hosted in an off-premise data center users connect to and pay for in a utility model ? ?by the drink.? Customers don?t own the license or hardware; rather, they connect to the application over a public or private network. SaaS makes sense for applications such as payroll, email or even sales force automation, but this is hardly a complete roster of the applications an enterprise would require to run a business. If you want the attributes of the public cloud and you can find a SaaS solution that works for you, use it. But don?t think for a second that this is a complete strategy for your IT needs. Very few companies will find SaaS a complete strategy for IT.
Platform as a Service (PaaS) – A PaaS model means the servers, storage, and development environment for a specific custom application are hosted by a specific supplier, such as the ecommerce web engine owned by Amazon. Customers write and host their applications on that provider?s network, paying by the megabyte and CPU cycle. PaaS models are most appropriate for specific, niche applications. They also can be used for the testing and development of a new program. Yet, this model hasn?t proved robust or scalable enough for strategic, mainstream enterprise computing. Further, the long term cost savings that this model promises is very suspect.
Infrastructure as a Service (IaaS) – This is a virtualized infrastructure in the sky ? sometimes without even an operating system ? you connect to and do with it whatever you wish. IaaS is essentially a co-location strategy where the IT assets are virtualized and provided to you in a ?by-the-drink? consumption model. This model is akin to the co-location craze of the late 90?s and early 2000?s. The new twist is the economic leverage that service providers get from virtualization technology. Like SaaS and PaaS, there are some very meaningful ways to take advantage of this compute model, but it in no way represents a panacea for lower costs or easier management of an enterprise?s entire IT requirements.
The Dark Side of the Public Cloud
Defining the cloud is just the beginning. Beyond that, you must also understand the impact cloud technologies can have on your enterprise ? both good and bad.
Control: When data is moved to the public cloud, businesses no longer have control over that data. Period. Once you move the data, your cloud provider has "got you" because it is very difficult and costly to move it back. Your business may own the data, but it is essentially held hostage. Consider the rise and fall of co-location providers in 2001 and 2002: they took on tremendous debt to build out their facilities, went bankrupt, and customers with strategic applications running in these facilities had to scramble. This turned out to be a recipe for disaster: the enterprise?s data was hosted on an unowned asset and was not available to them when they needed it.
Security: Placing enterprise data in a public cloud is similar to sending your children to a daycare with no control over or visibility into the environment. No parent would take this risk. Likewise, no enterprise should put critical data into a public cloud environment to save the mere 10 percent Gartner Group predicts of their operating costs. The risks are too significant and the return is too little. This is not to say that cloud providers won?t go to great lengths to secure your data. However, as a client, you must understand that anytime you give up control of your data, you introduce significant security risk.
Economics: With the public cloud, enterprises are just moving money from one pocket to another. Despite what service providers may promise, they will face the same challenges in terms of scalability, quality of service, and cost-efficiency that your enterprise faces internally ?making that 10 percent savings unlikely. Add to this that service providers are notorious for billing inaccuracies; So much so that there is a cottage industry of companies whose sole charter is to find money companies are over-charged by service providers.
Enterprises are being led down a primrose path to the public cloud. Once they are there, there is little hope to turn back. My advice: Take advantage of all the attributes of public cloud, but build a private cloud with infrastructure you own in environments you control.
Dave Hart is Chief Technology Officer at Presidio, Inc.
