You don’t have to do much Googling to find articles, podcasts and tweets featuring me talking about both multi-cloud and hybrid cloud. More companies than ever are choosing a hybrid cloud approach that leverages a multi-cloud strategy, so it’s prudent to revisit the pros and cons of hybrid and multi-cloud, as well as public and private cloud infrastructure.
I am defining public and private clouds as the environments in which an organisation chooses to host its infrastructure. Hybrid and multi-cloud are the strategies organisations employ for these environments.
The environments: Private vs. public
I will caveat everything I’m about to say with the fact that you should choose the right environment for the right workloads. What problem are you solving and why? There is a case to be made for private cloud infrastructure, and there is a case to be made for public cloud — it entirely depends on what type of applications you are running and what the requirements are around that application.
Today, one of the key private cloud advantages is data — be it addressing data sovereignty requirements, or because you have a large data lake in your private cloud and need close access to it (for low latency application requirements), or you have specific regulation requirements on who has access to that data and where that data sits. Data is often at the heart of private cloud strategies.
Another benefit of private cloud to an organisation is the customisation it gives the business, granting greater flexibility and the means to design a bespoke environment for specific business needs and users.
So, what are some of the drawbacks of private cloud?
They can be high maintenance. A dedicated team is required to manage the environment full-time, ensuring the environment stays up to date, including addressing any CVEs, as well as reliability, minimising any failures or downtime. A private cloud can be costly, as it requires a data centre as well as the physical infrastructure, in addition to the customised private cloud software to manage the environment in a way that mimics a public cloud experience (ease of access, self-service, etc.). You also run into limitations on scale that you would not have in a public cloud; while this is addressable, it does require forward-looking planning on what possible scale your environment would need to run in a variety of scenarios.
What about public clouds?
Public cloud can be less expensive because the data centre, hardware, and software are owned and operated by a third-party provider. Because a public cloud provider is responsible for dozens — or hundreds — or thousands — of customers, the network of servers is vast and largely diminishes the risk of failure, so count high reliability as yet another perk of public cloud. This combination of a massive network of servers and a 24/7 service team provides an additional benefit: scalability.
Are there any downsides to public cloud?
Remember how private clouds are able to be customised for an organisation’s specific business needs? Public cloud is often a one-size-fits-all solution, meaning a company no longer has as much control or flexibility with the public cloud. Public clouds can also be costly, especially if you have a growing footprint of workloads that require intensive data requirements. Additionally, egress fees can be quite high if you are looking to pull your data out of the cloud.
Why the ‘accidental hybrid’ cloud exists, and how to manage it
The strategies: multi-cloud and hybrid
A multi-cloud strategy simply means that an organisation has chosen to use multiple public cloud providers to host their environments. A hybrid cloud approach means that a company is using a combination of on-premises infrastructure, private cloud and public cloud — and possibly more than one of the latter, meaning that company would be implementing a multi-cloud strategy with a hybrid approach. At times, these terms are used interchangeably.
Companies choose a multi-cloud strategy for a multitude of reasons, not least of which is avoiding vendor lock-in. Spreading workloads across multiple cloud providers increases reliability, as a company is able to fail over to a secondary provider if another provider experiences an outage.
Optionality is a huge benefit to companies who want to be able to pick and choose which services will most seamlessly integrate into their environments, as each major public cloud provider provides some unique services for different types of workloads. Furthermore, when a company uses multiple public cloud providers, it retains flexibility and can transfer workloads from one provider to another. Finally, global organisations can leverage multi-cloud to address complex compliance requirements, which vary from country to country.
These are all very strong cases for multi-cloud, but what are the downsides?
Cost forecasting and containment can be challenging when using multiple providers charging different rates for different services. Also, spreading workload across multiple cloud providers does increase reliability, but it can also increase risk and make it more difficult to know where data is and who has access to it. There are both benefits and downsides to multi-cloud, but I am a proponent of a multi-cloud strategy whenever possible.
Why do organisations choose a hybrid approach?
Many companies — especially large enterprises that existed for decades — host their environments in the data centre, and lack of resources, funding, staff, executive buy-in, or a host of other reasons may prevent them from shifting their legacy architecture to the cloud. However, certain teams within the company may be spinning up cloud-native environments for new projects, and other teams may be working on implementing a lift-and-shift to the cloud from the data centre.
For most organisations large and small, a multi-cloud strategy with a hybrid cloud approach is the way of the future. As applications grow across organisations, their infrastructure needs change as well. For example, you might be running a large CRM system in a private cloud, but you may choose to run newer, cloud-native applications in a public cloud where you can leverage the cloud infrastructure to the fullest extent.
At the end of the day, organisations should choose the right infrastructure for the right workload and business needs, whether that’s a hybrid and/or multi-cloud strategy using either/both public and/or private clouds.