A hybrid cloud provides you with the largest number of options, according to those that sell them. You get a private cloud coupled with one or more public clouds, with workloads distributed across them.
IT is often told that starting with a private cloud and then going hybrid is a straightforward, sensible strategy. But it’s not as easy as you’ve likely been told.
I often hear that it’s a much more difficult process to move from a private cloud to a public or hybrid cloud than it is to move directly to a public cloud from traditional on-premises systems.
The appeal of using public clouds is clear: Public clouds have thousands of services ready to go, including advanced security and monitoring services. Moreover, there is no hardware and software you have to maintain nor datacenter space to rent or purchase. A private cloud requires both.
That’s why very few enterprises have moved from a public-cloud-only approach to hybrid approach. But very many enterprises have moved from a private-cloud-only approach to a hybrid-cloud approach.
Sadly, the move from a private cloud to a public cloud is not easy, whether you go hybrid or all-public. The main reason is that there is no direct mapping from private cloud services, which are the basics (storage, compute, identity access management, and database) to public cloud services which have those basic services plus thousands of other higher-end services.
Private clouds today are where public clouds were in 2010. Public clouds today are in 2018. You’re in essence migrating over a ten-year technology advance as you move your applications between private and public.
Complexity also comes in when you’ve already coupled your applications to the services in the private cloud, which is typically going to be OpenStack. There are very few OpenStack deployments on public clouds, none of which are the Big Three providers (Amazon Web Services, Google Cloud Platform, and Microsoft Azure).
That means you can’t do an A-to-A mapping of the cloud services from your private cloud to the public clouds. And that in turn means you need to remap these services to similar services on the public cloud.
But you can’t stop there. You also need to map to the higher-level services that were not available on the private clouds—including security services, governance services, and database services—to improve each application’s ability to leverage all it needs from the public cloud provider.
The primary issue is that you have to remap services that are very different. They may appear to be similar because they are “cloud,” but they are not—and that’s the issue. When you go from a traditional on-premises system, you know it is not cloud-like and thus know to essenrtially start over.