We live in a world where we like to name things. In the case of cloud computing, the names revolve around patterns of use: public cloud, private cloud, and hybrid cloud. Now there’s a new term, multicloud, for an emerging pattern of use for cloud computing.
Terms and definitions
“Multicloud” means using more than a single public cloud. That usage pattern arose when enterprises tried to avoid dependence on a single public cloud provider, when they chose specific services from each public cloud to get the best of each, or when they wanted both benefits.
Defined: “Multicloud” vs. “hybrid cloud”
So, how does multicloud relate to hybrid cloud? Some people use them interchangeably, but they do have distinct meanings. A hybrid cloud is the pairing of a private cloud (an on-premises datacenter built on cloud technologies) and a public cloud.
If you use multiple public clouds with a private cloud, that is still a multicloud. (Some people might call it a hybrid multicloud, which is fine.)
“Pragmatic hybrid cloud” defined
There’s also a beast called a pragmatic hybrid cloud, which is the pairing of a traditional enterprise datacenter with a public cloud; these exist because many enterprises have been disappointed with private clouds and so sought a way to combine what they already had with the public cloud.
By contrast, a multicloud architecture uses two or more public clouds.
What’s behind the multicloud trend
As a trend, cloud computing is getting more complex. The vision a few years ago was of placing workloads on a single cloud, whether public or private. But then the hybrid cloud architecture became a more attractive option because it gave enterprises more choice.
Enterprise IT wanted that choice because both Google and Microsoft developed compelling public cloud platforms, providing alternatives to Amazon Web Services, which had started the public cloud business. Other enterprise providers—including IBM, HP Enterprise, and more recently Oracle—jumped into the fray as well, though with considerably less success.
Because these are all viable public cloud options, enterprises began to mix them together, both through formal architectural processes and through “shadow IT,” where groups in companies that used a public cloud without the knowledge of enterprise IT. Various shadow IT efforts often picked different public clouds and then wanted those cloud operations to be managed by enterprise IT.
No matter how you got there, most enterprises now manage a multicloud infrastructure.
Although many IT organizations simply manage these complex multicloud environments using the native tools and services from each cloud, a few are getting smart and abstracting themselves away from the complexity.
By using tools such as cloud management platforms (CMPs) and cloud service brokers (CSBs), enterprises can manage multiple clouds as if they were a single cloud. However, the trade-off is that you can only use a subset of features from each cloud; that is, take the “least common denominator” approach.
Advice: Focus on what cloud technologies do, not what they are called
Public cloud, private cloud, hybrid cloud, pragmatic hybrid cloud, multicloud: semantic overload? Indeed.
However, I suggest that you not get caught up with what things are called, but instead focus on what they do. It’s a fact that cloud architectures will evolve in the new few years, and new patterns will emerge as well. New names will come, too, I’m sure.