The Cisco Global Cloud Index says that 68% of enterprise workloads will be executed in the public cloud by the end of 2020. Another 24% will be executed in private cloud infrastructure, bringing the total for cloud computing to 92%.
So, why don't all those users of the public cloud simply become the standard and everyone else move in that direction? It's hard enough to see why the traditional data center is still hanging around at 8% of the total by the end of 2020.
Why does it need to survive at all, and why will private cloud infrastructure be hanging on then as well? Why not realize maximum gains by moving everything into the public cloud? Aren't the largest economies of scale be achieved there?
[Considering Hadoop? Read Hadoop Pros and Cons for Enterprise Users.]
Part of the answer is that even public cloud providers understand some customers have reasons to keep a portion of their compute load off multi-tenant public cloud servers. Also, some customers have large applications where any form of latency is an issue, and they want their workload to run unimpeded by others on a bare metal server.
As a result, service providers offer the option of private cloud servers, accessible only through a virtual private network or over a private line.
But there are other reasons private clouds are necessary or desirable, which we'll explore in the following pages. The private cloud isn't necessarily a laggard, a dinosaur waiting for its day of extinction, post legacy data centers. In many cases, it's a more specialized beast, designed to fulfill specific purposes that can't be easily met in the public cloud.
If a task is mission-critical to the company, the resources devoted to it are frequently of a higher order, needing bigger servers, top-of-rack switches, and more instrumented monitoring than offered by the general purpose public cloud.
Remember, service provider AWS is building a cloud for the CIA, rather than putting the CIA in the public cloud.
The CIA needs a private cloud. Here's a look at why you may too.