Multi-cloud – more than just public and private

There's a difference between hybrid IT and multi-cloud, and there are different opinions on the definitions. One is that hybrid platforms are homogenous and multi-cloud platforms are heterogenous. Homogenous here means that the cloud solutions belong to one stack, for instance, the Azure public cloud with Azure Stack on premises. Heterogenous, then, would mean combining Azure and AWS, for instance.

For now, we will keep it very simple: a hybrid environment is combining an on-premises stack – a private cloud – with a public cloud. It is a very common deployment model within enterprises. There have been numerous reports that stated some years ago that most enterprises would transform their IT to the public cloud by 2020. It was the magic year, 2020, and a lot of organizations developed a Cloud Strategy 2020. It certainly did have a nice ring to it, but magical? Not really. These same organizations soon discovered that it was not that easy to migrate all of their systems to a public cloud. Some systems would have to remain on premises, for various reasons.

Two obvious reasons were security and latency. To start with the first one: this is all about sensitive data and privacy, especially concerning data that may not be hosted outside a country, or outside certain regional borders, such as the EU. Data may not be accessible in whatever way to – as an example – US-based companies, which in itself is already quite a challenge in the cloud domain. Regulations, laws, guidelines, and compliance rules often prevent companies from moving their data off premises, even though public clouds offer frameworks and technologies to protect data at the very highest level. We will discuss this later on in this book, since security and data privacy are of utmost importance in the cloud.

Latency is the second reason to keep systems on premises. One example that probably everyone can relate to is that of print servers. Print servers in the public cloud might not be a good idea. The problem with print servers is the spooling process. The spooling software accepts the print jobs and controls the printer to which the print assignment has to be sent. It then schedules the order in which print jobs are actually sent to that printer. Although print spoolers have been improved massively over the last years, it still takes some time to execute the process. Print servers in the public cloud might cause delays in that process. Fair enough: it can be done, and it will work if configured in the right way, in a cloud region close to the sending PC and receiving printer device, plus accessed through a proper connection.

You get the idea, in any case: there are functions and applications that are highly sensitive to latency. One more example: retail companies have warehouses where they store their goods. When items are purchased, the process of order picking starts. Items are labeled in a supply system so that the company can track how many of a specific item are still in stock, where the items originate from, and where they have to be sent. For this functionality, items have a barcode or QR code that can be scanned with RFID or the like. These systems have to be close to the production floor in the warehouse or – if you do host them in the cloud – accessible through really high-speed, dedicated connections on fast, responsive systems.

These are pretty simple and easy-to-understand examples, but the issue really comes to life if you start thinking about the medical systems used in operating theatres, or the systems controlling power plants. It is not that useful to have an all-public cloud, cloud-first, or cloud-only strategy for quite a number of companies and institutions. That goes for hospitals, utility companies, and also for companies in less critical environments.

Yet, all of these companies discovered that the development of applications was way more agile in the public cloud. Usually, that's where cloud adoption starts: with developers creating environments and apps in public clouds. It's where hybrid IT is born: the use of private systems in private data centers for critical production systems that host applications with sensitive data that need to be on premises for latency reasons, while the public cloud is used to enable the fast, agile development of new applications.

Multi-cloud as a true mixed zone

From the analogy with the smartphone, it should be clear that with multi-cloud we're also talking about services, much more than just hosting systems in a private data center and a public cloud. This would mainly be Infrastructure as a Service (IaaS), where organizations run virtualized and non-virtualized physical machines in that private cloud and virtual machines in the public cloud.

In multi-cloud setups, we are also talking about Platform as a Service (PaaS) and Software as a Service (SaaS). In multi-cloud setups, it can become much more of a mixed mode, just as on our smartphone that holds data on the device itself stores and retrieves data from other sources, connecting remotely to apps or hosting the apps on the phone, making use of services through APIs in that app.

In multi-cloud, we can do exactly the same, leveraging functions and applications running on virtual machines on a private system with SaaS functionality connecting over the internet from a third-party provider, for example, to execute specific data analytics. The data may still reside in a private environment, where the runtime environment is executed from a public cloud source, or the other way around in the case of running models against data lakes that are fed with data streams from different sources, where the results of these models are delivered to private systems.

That is what multi-cloud is all about. Leveraging applications, data, and services from different cloud platforms and using different delivery models such as PaaS and SaaS. It might include hybrid IT, but it is more of a mixed mode in order to create more added value for the business by combining and optimizing cloud solutions. The next question is: how can organizations create that optimum combination of services, and by doing so, create that added value for their business?

Let's dive into the definition of a real cloud strategy.