To this day weâ€™ve had a hard time getting our arms around just what exactly a private cloud is. More to the point, where does it depart from server consolidation? The common thread is that both cases involve some form of consolidation. But if you look at the definition of cloud, the implication is that what differentiates private cloud from server consolidation is that youâ€™re talking a much greater degree of virtualization. Folks, such as Forrester’s John Rymer, fail to see any difference at all.
The topic is relevant as â€“ since this is IBM Impact conference time, there are product announcements. In this case, the new WebSphere Cloudburst appliance. It manages, stores, and deploys IBM WebSphere Server images to the cloud, providing a way to ramp up virtualized business services with the kinds of dynamic response that cloud is supposed to enable. And since it is targeted for deployment to manage your resources inside the firewall, IBM is positioning this offering as an enabler for business services in the private cloud.
Before we start looking even more clueless than we already are, letâ€™s set a few things straight. Thereâ€™s no reason that you canâ€™t have virtualization when you consolidate servers; in the long run it makes the most of your limited physical and carbon footprints. Instead, when we talk private clouds, weâ€™re taking virtualization up a few levels. Not just the physical instance of a database or application, or its VM container, but now the actual services it delivers. Or as Joe McKendrick points out, itâ€™s all about service orientation.
In actuality, thatâ€™s the mode you operate in when you take advantage of Amazonâ€™s cloud. In their first generation, Amazon published APIs to their back end, but that approach hit a wall given that preserving state over so many concurrent active and dormant connections could never scale. It may be RESTful services, but they are still services that abstract the data services that Amazon provides if you decide to dip into their pool.
But weâ€™ve been pretty skeptical up to now about private cloud â€“ weâ€™ve wondered what really sets it apart from a well-managed server consolidation strategy. And thereâ€™s not exactly been a lot of product out there that lets you manage an internal server farm beyond the kind of virtualization that you get with a garden variety hypervisor.
So we agree with Joe thatâ€™s itâ€™s all about services. Services venture beyond hypervisor images to abstract the purpose and task that a service performs from how or where it is physically implemented. Consequently, if you take the notion to its logical extent, a private cloud is not simply a virtualized bank of server clusters, but a virtualized collection of services that made available wherever there is space, and if managed properly, as close to the point of consumption as demand and available resources (and the cost of those resources) permits.
In all likelihood, early implementations of IBMâ€™s Cloudburst and anything of the like that comes along will initially be targeted on an identifiable server farm or cluster. In that sense, it makes it only a service abstraction away from what is really just another case of old fashioned server consolidation (paired with IBMâ€™s established z/VM, you could really turn out some throughput if you already have the big iron there). But taken to its more logical extent, a private clouds that deploys service environments wherever there is demand and capacity, freed from the four walls of a single facility, will become the fruition of the idea.
Of course, thereâ€™s no free lunch. Private clouds are supposed to eliminate the uncertainty of running highly sensitive workloads outside the firewall. Being inside the firewall will not necessarily make the private cloud more secure than a public one, and by the way, it will not replace the need to implement proper governance and management now that you have more moving parts. Thatâ€™s hopefully one lesson that SOA â€“ dead or alive â€“ should have taught us by now.