What does 'hybrid cloud' mean?
A hybrid cloud mixes two or more types of cloud environments. Hybrid cloud deployments combine public* and private clouds**, and they may also include on-premise legacy infrastructure. For a cloud to truly be hybrid, these different cloud environments must be tightly interconnected with each other, essentially functioning as one combined infrastructure. Almost all hybrid clouds include at least one public cloud.
A hybrid cloud is somewhat like a hybrid car. Hybrid cars combine two totally distinct technologies: an engine that burns gasoline and electric power. Each technology functions in a totally different way, and each one has its benefits and drawbacks. However, when the two are combined effectively, the result is a car that is more efficient than most gasoline-only cars and yet more powerful than most all-electric cars. Similarly, hybrid clouds combine the benefits of multiple types of cloud environments for greater efficiency and functionality.
Hybrid clouds have a number of uses. An organization may use their private cloud for some services and their public cloud for others, or they may use the public cloud as backup for their private cloud. They can also use the public cloud to handle periods of high demand, while keeping most operations within their private cloud.
(For more on how cloud technology works, see What Is the Cloud?)
What are the types of environments found in hybrid clouds?
The combination of any two of the environments listed below can be considered "hybrid cloud":
- Public cloud: A public cloud is a cloud service run by an external vendor that may include servers in one or multiple data centers. Public clouds are shared by multiple organizations. Using virtual machines, individual servers may be shared by different companies, a situation that is called "multitenancy" because multiple companies are renting server space within the same physical server.
- On-premise private cloud: A private cloud is a data center wholly dedicated to one company. The servers in a private cloud aren't shared by anyone else's software, files, or data. On-premise private clouds are maintained and secured by the organizations themselves, not an external vendor.
- Hosted private cloud: This is just like an on-premise private cloud in that the servers are dedicated wholly to one organization. However, the cloud servers in a hosted private cloud are not located in an organization's offices – rather, a third-party provider hosts and maintains the cloud servers in one or more remote data centers, and the organization accesses the cloud over the Internet instead of an internal network. But unlike a public cloud, there is no multitenancy; the cloud servers are not shared with other organizations.
- On-premise (legacy): On-premise or legacy deployments don't use cloud technology at all. Instead, organizations using this model follow the classic practice of purchasing software licenses, installing and maintaining hardware on their premises, and installing software locally on employee computers. In other words, instead of working in Google Docs (for example), employees would use Microsoft Word, or some other program installed and running on their computers.
What is the difference between hybrid cloud and multi-cloud?
A multi-cloud deployment combines multiple public clouds, while a hybrid cloud combines a public cloud with another type of environment. Hybrid clouds combine apples and oranges – a multi-cloud deployment is more like combining many types of apples.
A multi-cloud can also be a hybrid cloud if it mixes multiple types of cloud environments, in addition to using multiple public clouds – just as a rectangle can be a square, but not all rectangles are squares. Conversely, a hybrid cloud deployment can also be multi-cloud if it uses several public clouds.
How do the different environments communicate with each other in a hybrid cloud?
For a hybrid cloud to work well, the connection between the separate clouds is key. Public clouds, private clouds, and on-premises infrastructure can connect to each other in a variety of ways, including:
- APIs (Application Programming Interfaces)
- VPNs (Virtual Private Networks)
- WANs (Wide Area Networks)
Without a working connection between clouds, an organization is not running a hybrid cloud – they are merely running two or more separate cloud environments in parallel, and they won't reap the benefits of hybrid cloud deployments.
What are the advantages of using a hybrid cloud architecture?
- Flexibility: Hybrid clouds make it easier to switch to a different style of cloud deployment. For instance, if a business decides to move to an exclusively public cloud deployment, it will be simpler if some business processes or storage already take place in a public cloud.
- Wider variety of technology: Via a public cloud, a business can include technology that isn't practical to run in a private cloud, such as big data processing.
- Backups to avoid downtime: If one cloud crashes or breaks, a company can rely on the other cloud, avoiding service interruptions. This type of redundancy is also an advantage of multi-cloud deployments.
- Meet spikes in demand: A company can run most of its processes in a private cloud, and then use a public cloud for extra computing power to handle a sudden spike in workload – such as when far more users than normal access an [eCommerce site](https://www.cloudflare.com/ecommerce/) during Black Friday. This strategy is known as cloud bursting, because a workload "bursts" from one cloud to a larger cloud.
- Potential cost savings: Maintaining an internal data center, such as a private cloud, can be expensive and resource-intensive. By moving some operations to a public cloud, an organization doesn't have to maintain as much infrastructure on-premises, cutting down on costs.
- Keep sensitive data on-premise: Some organizations handle sensitive data, such as credit card numbers, healthcare information, or financial data. Keeping such data on-premise gives a company much more control over the security measures that guard sensitive data. In a hybrid cloud deployment, an organization can keep sensitive data in a secure private cloud, and then use public clouds for running the rest of their applications.
What are the drawbacks of using a hybrid cloud architecture?
- Greater attack surface: Whenever network infrastructure becomes more complex, there is a greater chance that an attacker will find a vulnerability to exploit. A single cloud – say, a private cloud – can have strong security protections in place. But if multiple clouds from different vendors are used, not all clouds will have the same quality of security.
- More complex integrations: The connection and orchestration between different kinds of clouds is crucial. Thus, there are more steps to setting up a hybrid cloud compared to deploying a single public cloud or a single private cloud, since the connecting technology – such as a VPN – has to be set up and maintained too.
- Complicated to secure: While an on-premise private cloud runs behind the company firewall, a hosted private cloud or public cloud does not. A company may need to use multiple security products, some for their on-premises cloud and some for their public cloud, to keep their data safe. In addition, it can be tricky to validate a user's identity across multiple clouds (access control).
How does Cloudflare integrate with hybrid cloud deployments?
The Cloudflare global network sits between end users and Cloudflare customers' infrastructure, protecting both users and companies, and accelerating traffic to and from the users. Cloudflare can be deployed in front of any type of network infrastructure, including hybrid cloud and multi-cloud.