Public, Private, Hybrid, Multicloud, Distributed Cloud — Which one is right for you?

DaveWeck
AI+ Enterprise Engineering
5 min readDec 8, 2020
It is not always a straight path on the journey to cloud

With all the options out there today for a journey to cloud, it can be very confusing on which path or combination of paths your business should take, and you may end up taking a few turns in direction before moving up to where you want to be in the future.

Let me start with a few definitions

Public Cloud: Building or migrating applications and services to one of the many Public Cloud IaaS/PaaS providers and not relying on infrastructure on client premise

Private Cloud: Located on a client premise and it is based on virtualizing physical infrastructure leveraging VMs or Containers.

Hybrid Cloud: Leverages a combination of a single Public Cloud and client on premise Private Cloud infrastructure, typically where some of the front end systems of engagement is located in Public Cloud and the back end source of record is still located on client premise on a private cloud or in a client’s legacy data center.

Distributed Cloud: This is where a client is using a single Public Cloud and still has a need to have some infrastructure on client premise but still wants to leverage the same Public Cloud console to serve as a control plane for both the Public Cloud and tethered components deployed by the Public Cloud on your client premise.

MultiCloud: Essentially, this is using multiple Public Cloud providers instead of a single Public Cloud provider. One could argue this could be one or more private clouds as well, but my view is it is multiple Public Clouds.

Each client will have to decide which cloud option(s) are key to their journey to cloud to achieve the desired business results.

Single Public Cloud only option

If you are a startup without any existing compute infrastructure, then Public Cloud is an easy choice for most clients. Given the breath of offerings, the location choices, and the ability to start with cloud native application and services, Public Cloud is a great choice with many features and functions offering by providers like IBM Cloud, AWS, Azure, and GCP. The choice of which Public Cloud will come down to your specific business needs and who provides the right combination of price, services, and locations which are right for your business.

Distributed Cloud option

If you already have some on premise data centers and IT infrastructure then the choice become more complicated. If you are developing a new application leveraging a cloud native approach on a public cloud but still have some need to have some data or backend services on client premise, then a Distributed Cloud could be a good choice as a “Cloud In” approach. IBM Satellite, Google Anthos, Azure Arc, and AWS Output are all flavors of leveraging Public Cloud as the control plane and providing a common interface experience. Leveraging a Public Cloud catalog of services could be a great choice.

Private Cloud options

Private Clouds can certainly help optimize utilization of on premise servers by compressing a clients workloads into fewer VMs, which as a result will drive down costs assuming not all the consumers will have peak demands at the same time. Even with all the capabilities of Public Cloud, Private Clouds will have a key business role for many years.

Hybrid Cloud options

If you have private clouds already in your Data Centers, then the question is how do you extend from your on premise private cloud to Public Cloud(s) which is an “Enterprise Out” model. It is very likely some of your lines of business are already using Public Cloud completely isolated from your on premise private cloud. It is clear if you have a significant on premise IT infrastructure and you want to move enterprise applications and services to the cloud that some form of hybrid cloud between your private cloud and public cloud is a logical and good choice.

Hybrid Cloud coming from Public Cloud providers typically means some form of tether from the Public Cloud provider to on premise infrastructure. The better term for this is Distributed Cloud, as if you use IBM Cloud Satellite, GCP Anthos, Azure Arc or AWS Output you are tethered back to those Public Clouds.

Hybrid Cloud coming from using legacy VMware is essentially doing a lift and shift from on premise to a public cloud, and most often this actually increases the cost of the infrastructure, but it does provide easy scale up and scale down at the VM unit level.

A better approach to maximizing the ROI is to initiate on premise application modernization initially through containerizing those applications onto a private or public cloud which allow better efficiencies of the hardware including better memory utilization. Containerization also allows the evolution to microservices based architecture and better alignment to agile methodology and DevOps squad organizational alignment. This fosters speed to market for creating new features and functions via MVPs, allows testing which ones work best, and adopting continuous integration and continuous delivery to ensure the new functionality is quickly in the hands of your clients.

However, which cloud does one chose for containerized workloads.

Hybrid Multicloud option is best of all for Enterprise workloads, especially containerized workloads which clients may initially start running on premise private cloud but later want to shift those workloads to various Public Clouds without having to change the DevSecOps experience.

For many Hybrid cloud is a great approach, but ensuring your hybrid cloud strategy works consistently across multiple Public and your private clouds is where a Hybrid Multicloud PaaS comes into play. If you are a CEO/CIO, you clearly want to develop a common DevSecOps experience across both Public and Private Cloud for all lines of business. This allows a common implementation and execution of toolchains, security policies, cloud standards, leveraging the same skillset across clouds, and enabling common new ways of working. It provide protection if a single Public Cloud creates situations which are unfavorable to your business in the future. This could be significant increase in the cost, the Public Cloud provider entering the same business as you are in, or your needs have changed and other Public Cloud simply offer a better advantage for your business. (e.g. support for regulated workloads, etc)

PaaS platforms such as Red Hat OpenShift create the ability to implement a standard opinionated, certified Kubernetes certified, and it is based on upstream open source software enabling a consistent platform across the major Public Clouds, and on private clouds, and across various compute infrastructure (x86, Power, Mainframe). Leveraging Hybrid Multicloud opens up the ability to shift applications and services between on premise private clouds and various Public Clouds without having to change the approach to development, operations and security.

While for some a single Public Cloud may be a good choice, creating a situation where depending on the workload, one has portability to shift that workload between private cloud and multiple Public Clouds seems like a winning combination of what I call Hybrid Multicloud.

Shifting from independent clouds to a Hybrid Multicloud approach

Just like the picture of the tree which decided to take several turns over the year to getting to where it ultimately wanted to go, keep open your options to change your initial landing zone decision without having to redesign your development and operational models.

Let me know what you think.

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DaveWeck
AI+ Enterprise Engineering

IBM Distinguished Engineer, Cloud Engagement Hub. A cross-business unit, high performance team designed to drive strategic Cloud opportunities for IBM clients