Today’s private clouds must accommodate a range of new needs and use cases that the private clouds of the past rarely contended with. At the same time, new technologies (or old technologies that have matured) have created novel opportunities for building out hybrid clouds.
For both of these reasons, redefining private cloud architectures is one key step in modernizing hybrid cloud.
The Private Cloud Architectures of Old
In the early days of private cloud – which is to say, about a decade ago – private cloud architectures and use cases were simple.
At the time, the main reason for using a private cloud was to keep resources on-premises in order to meet security or compliance goals. The services included in private cloud architectures were relatively few; usually, they amounted to basic IaaS services like storage and compute.
For the most part, the private clouds of this era were constructed using proprietary platforms from vendors like Citrix and VMware (to name just a couple of examples). Although open source frameworks for private cloud, like OpenStack, have been around for the past decade, they were not yet sufficiently mature or well-known at the time to attract widespread adoption.
Today’s Private Cloud Requirements
The private clouds of the present require more sophisticated architectures because they must address more complex use cases and needs, including:
- The need to integrate seamlessly with public cloud resources, while still keeping private cloud infrastructure private and geographically isolated. Today, private clouds often exist alongside or as part of a hybrid or multi-cloud strategy, rather than being the only cloud that a business uses.
- The ability to isolate private cloud workloads at the network level, as well as at the physical level.
- Support for running on the infrastructure that a company already has in place, as well as the infrastructure it may acquire in the future.
- The ability to deliver a range of cloud services using private infrastructure. Today’s private clouds must support not just basic storage and compute services but also containers, serverless functions, cloud-based CI/CD, data analytics and more.
The Turn to Open Source
These requirements have imposed new challenges for private cloud architectures, which must be more flexible, vendor-agnostic and integration-friendly than the private clouds of a decade ago.
These challenges might have been hard to meet if your only option for building a private cloud were to adopt a single proprietary platform from one vendor. Fortunately, however, the expansion of the open source ecosystem surrounding private cloud technologies has made it easier to build private clouds in a flexible, self-service manner.
One big step forward is the maturation of OpenStack, which for the past five years or so has been ready for primetime. Today, OpenStack can be used to build out a private cloud that supports a wide array of different cloud services.
The open source KVM (Kernel-based Virtual Machine) hypervisor offers another important opportunity for organizations building private clouds today. Although, like OpenStack, KVM has been around for more than a decade, it has only been in the past seven or eight years that it has fully matured. By freeing organizations from dependence on proprietary virtualization platforms, KVM not only makes it easier to build private cloud infrastructure tailored to their needs, but also provides more orchestration options for managing virtual machines.
Beyond OpenStack and KVM, a variety of other open source projects offer tools or platforms that can be integrated into private clouds built with open source technologies. Examples include Ansible, Qinling, MongoDB, Ceph and OpenvSwitch, to name just a few key projects.
What all this means is that, over the past several years, it has become much easier to build a cost-efficient private cloud tailored to an organization’s specific needs. Gone are the days when you had to adopt one proprietary private cloud platform or another and accept the functionality it offered (or didn’t offer), like it or not.
The Challenges of Open Source Private Cloud Architectures
The opportunities that open source has created for private cloud architectures are not without their drawbacks. Although private clouds based on open source technologies offer powerful innovation, they also present challenges:
- Finding the expertise to work with open source private cloud technologies can be difficult. And because open source projects themselves don’t typically offer their own enterprise-class support channels, having experts on your side when working with open source private clouds is critical.
- Open source technologies constantly evolve. Some projects are also discontinued. Navigating the open source private cloud ecosystem, and staying on top of changes that could impact the architecture you use, is therefore daunting for many teams.
- Not all proprietary cloud platforms or public cloud services are designed to integrate well with open source private clouds.
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These reasons explain why some organizations today opt to use proprietary frameworks, like Azure Stack or AWS Outposts, to build their private clouds. These platforms come with a much higher degree of vendor lock-in, but they are also more straightforward to use. Professional support is also available directly from the vendors if you need it.
Which Architectural Strategy is Best?
How do you decide, then, which type of architecture is best for building a private cloud today?
Clearly, open source architectures have major advantages. Their biggest drawback is that they can be more difficult to manage over time, especially for teams that try to DIY their private clouds while lacking the considerable in-house expertise in open source technologies to pull this off.
That challenge, however, can be solved by turning to vendors like Platform9, which offers management expertise in OpenStack and all of the other major open source technologies used to build private clouds today. With a fully-managed private cloud solution, organizations get the best of both worlds: The flexibility and customization of an open source private cloud architecture, as well as the reliability and manageability of a private cloud supported by a team with deep expertise in the relevant open source technologies and ecosystem.