Learn how to support a full range of applications and workloads using a mix of private and public cloud services.
What is hybrid cloud?
Hybrid cloud is a computing environment that connects a company’s on-premises private cloud services and third-party public cloud into a single, flexible infrastructure for running the organization’s applications and workloads.
The principle behind hybrid cloud is that its mix of public and private cloud resources—with a level of orchestration between them—gives an organization the flexibility to choose the optimal cloud for each application or workload (and to move workloads freely between the two clouds as circumstances change). This enables the organization to meet its technical and business objectives more effectively and cost-efficiently than it could with public or private cloud alone.
The benefits of hybrid cloud are easier to understand once you know more about the capabilities, limitations, and uses of private and public clouds.
Private cloud vs. public cloud vs. hybrid cloud
In the private cloud model, cloud infrastructure and resources are deployed on-premises and owned and managed by the organization.
Private cloud requires a large upfront capital expense for equipment and software, a lengthy deployment, and in-house IT expertise to manage and maintain the infrastructure. It’s also expensive and time-consuming to scale capacity (because you have to purchase, provision, and deploy new hardware) and add capabilities (because you have to purchase and install new software). But private cloud provides maximum control over the computing environment and data, which is especially important—or even mandatory—if your company deals with highly sensitive data or is subject to strict industry or governmental regulations.
In the public cloud model, a company consumes compute, network, storage, and application resources as services that are delivered by a cloud provider over the Internet.
The cloud provider owns, manages, provisions, and maintains the infrastructure and essentially rents it out to customers, either for a periodic subscription charge or fees based on usage.
Public cloud offers significant cost savings because the provider bears all the capital, operations, and maintenance expenses. It makes scalability as easy as requesting more capacity, and it lets your company’s IT staff focus more on revenue-driving activities and innovation and less on “keeping the lights on.”
But, with public cloud, you sacrifice a degree of control over the computing environment and are subject to the performance and security of the cloud provider’s infrastructure.
The hybrid cloud model represents the best of both worlds. You can run sensitive, highly regulated, and mission-critical applications and workloads or workloads with reasonably constant performance and capacity requirements on private cloud infrastructure. You can run less-sensitive, more-dynamic, or even temporary workloads (such as development and test environments for a new application) on the public cloud.
With the proper integration and orchestration between the two, you can leverage BOTH (when needed) for the same workload. For example, you can leverage additional public cloud capacity to accommodate a spike in demand for a private cloud application (this is known as “cloud bursting”).
If you’ve read this far, you’ve likely concluded that the flexibility and division of labor enabled by hybrid cloud can offer significant benefits to almost any organization in several areas, including the following
Security and compliance
Hybrid cloud lets your organization deploy highly regulated or otherwise sensitive workloads in private cloud, while still being able to deploy less-sensitive workloads to public cloud services.
Scalability and resilience
You can’t always predict when workload traffic will spike, and even when you can predict spikes, you can’t always afford to purchase additional private cloud capacity for those spikes only. Hybrid cloud lets you scale up quickly, inexpensively, and even automatically using public cloud infrastructure and then scale back down when the surge subsides—all without impacting the other workloads running on your private cloud.
Resource optimization and cost saving
Hybrid cloud gives your IT more options and flexibility for deploying workloads in a way that makes the best use of your on-premises investments and your overall infrastructure budget. It also allows you to change that deployment in response to changing workloads or new opportunities.
For example, hybrid cloud lets you do any of the following:
- Establish a cost-optimal division of labor for workloads—say, maintain workloads with known capacity and performance requirements on private cloud and migrate more variable workloads and applications to public cloud resources.
- Quickly ‘spin-up’ a development and test environment using pay-as-you-go in the public cloud resources, without impacting on-premises infrastructure.
- Rapidly adopt or switch to emerging or state-of-the-art tools that can streamline your development, improve your products and services, or give you a competitive edge.
For a visual dive into hybrid cloud and the benefits it offers, watch “Hybrid Cloud Explained”:
Common use cases
Unless your organization was born on the cloud, you have a range of applications and workloads spread across private cloud, public cloud, and traditional IT environments that represent a range of opportunities for optimization via a hybrid cloud approach. Some increasingly common hybrid cloud use cases that might be relevant to your business include the following:
- SaaS integration: Through hybrid integration, organizations are connecting Software-as-a-Service (SaaS) applications, available via public cloud, to their existing public cloud, private cloud, and traditional IT applications to deliver new solutions and innovate faster.
- Data and AI integration: Organizations are creating richer and more personal experiences by combining new data sources on the public cloud—such as weather, social, IoT, CRM, and ERP—with existing data and analytics, machine learning and AI capabilities.
- Enhancing legacy apps: 80% of applications are still on-premises, but many enterprises are using public cloud services to upgrade the user experience and deploy them globally to new devices, even as they incrementally modernize core business systems.
- VMware migration: More and more organizations are “lifting and shifting” their on-premises virtualized workloads to public cloud without conversion or modification to dramatically reduce their on-premises data center footprint and position themselves to scale as needed without added capital expense.
Gartner defines two common types of hybrid cloud platforms: hybrid monocloud and hybrid multicloud.
Hybrid monocloud is hybrid cloud with one cloud provider—essentially an extension of a single public cloud provider’s software and hardware stack to the customer’s on-premises environment so that the exact same stack runs in both locations. The two environments are tethered together to form a single hybrid environment, managed from the public cloud with the same tools used to manage the public cloud provider’s infrastructure.
Hybrid multicloud is an open standards-based stack that can be deployed on any public cloud infrastructure. That means across multiple providers as well as on premises. As with hybrid monocloud, the environments are tethered together to form a single hybrid environment, but management can be done on- or off-premises and across multiple providers, using a common set of management tools chosen by the customer.
Hybrid multicloud architecture gives an organization the flexibility to move workloads from vendor to vendor and environment to environment as needed and to swap out cloud services and vendors for any reason.
A variant of hybrid multicloud called composite multicloud makes the flexibility even more granular—it uses a mix of microservices and cloud environments to distribute single applications across multiple providers and lets you move application components across cloud services and vendors as needed.
Monocloud vs. multicloud
Pros and cons exist for both approaches. Hybrid monocloud may be better if you’re confident that you can meet your application needs with a single vendor’s stack; you can’t justify the cost and management effort of working with multiple cloud vendors; or if you’re taking your first step from on-premises to hybrid.
But the flexibility of hybrid multicloud makes it almost inevitable for most organizations. In a recent Gartner survey, 81% of respondents reported working with two or more cloud vendors.
Hear more from Daryl Plummer, VP, Distinguished Analyst, Chief of Research and Chief Gartner Fellow on how enterprises are realizing an agile and responsive hybrid cloud architecture in this webcast featuring Gartner.
For a deeper dive on hybrid cloud architecture, see Sai Vennam's four-video series, starting with "Hybrid Cloud Architecture: Introduction":
Hybrid cloud strategy
Important considerations for your hybrid cloud strategy include the following:
- Use of open standards-based architectures
- Secure integration across cloud apps and data on- and off-premises
- Management of mixed clouds and providers across hybrid environments
- Automation of DevOps across providers and hybrid environments
- Movement of data and files between clouds, on- and off-premises, and across multicloud.
- Understanding security responsibilities.
Let’s look at each in more detail.
Cloud open standards
Open standards, as the name implies, are documented standards open to the public for use by anyone. Typically, the purpose of open standards is to allow for consistency and repeatability in approach. They are most often developed in collaboration by people who are invested in achieving the same outcomes.
In the case of hybrid cloud, open standards can help support interoperability, integration, and management. Some examples of open standards that support hybrid cloud include Kubernetes, Istio, OpenStack, and Cloud Foundry.
Hybrid cloud integration
Integration across applications and data—in the cloud and on- and off- premises—is an important component of any hybrid cloud strategy. Whether connecting applications from multiple Software-as-a-Service (SaaS) providers, moving parts of applications to microservices, or integrating with legacy applications, integration is key to ensuring the components of the hybrid ecosystem work together quickly and reliably.
To keep up with the pace of innovation, organizations need to be able to support a high volume of integration requests. While traditional integration styles and approaches are still important, more modern styles—such as API lifecycle management and event-driven architecture—are critical components of today’s integration ecosystem.
Modern integration requires speed, flexibility, security, and scale, and in recent years, businesses have started rethinking their approach to integration in order to drive speed and efficiency while lowering costs.
Decentralized teams using agile methods, microservices-aligned architectures, and the introduction of hybrid integration platforms are reshaping the way enterprises approach hybrid integration. Download the Agile Integration eBook to learn more about how business are thinking about integration modernization.
Hybrid cloud management
Management is another important component of a hybrid cloud strategy. Management includes, but is not limited to, provisioning, scaling, and monitoring across environments.
In a hybrid monocloud environment, management is relatively straightforward because with a single vendor, you can use the same tools to manage or provision across the infrastructure.
In a hybrid multicloud environment encompassing multiple cloud vendors, it is more of a challenge to manage consistently.
Kubernetes, the most popular container orchestration system, is an open source technology that works with many container engines. It can help with management tasks like scaling containerized apps, rolling out new versions of apps, and providing monitoring, logging, debugging, etc.
Differences in the specific Kubernetes implementations by cloud vendors can complicate management across environments but open source solutions like Red Hat OpenShift can simplify Kubernetes implementations by enabling orchestration and provisioning across different cloud environments, standardizing and treating the entire environment as a single stack.
DevOps and automation
At its core, DevOps is focused on automating development and delivery tasks and standardizing environments across the lifecycle of applications. One of the primary advantages of hybrid cloud is the flexibility to use the best fit environment to support individual workload requirements. DevOps methodology and tools like Red Hat OpenShift and Ansible help ensure a consistent approach and automation across hybrid environments and infrastructures, which is especially helpful in multicloud scenarios.
To learn more, check out the video “What is DevOps?”:
Hybrid cloud storage
Cloud storage allows you to save data and files to an off-site accessible via the public Internet or a dedicated private network connection. Data that you transfer off-site for storage becomes the responsibility of a third-party cloud provider. The provider hosts, secures, manages, and maintains the servers and associated infrastructure and ensures you have access to the data whenever you need it.
A hybrid cloud storage model combines elements of private and public clouds, giving organizations a choice of which data to store in which cloud. For instance, highly regulated data subject to strict archiving and replication requirements is usually more suited to a private cloud environment, whereas less-sensitive data (such as email that doesn’t contain business secrets) can be stored in the public cloud. Some organizations use hybrid clouds to supplement their internal storage networks with public cloud storage.
Hybrid cloud security
Enterprises worry that moving applications, services, and data beyond their firewalls to the cloud exposes them to greater risk. In fact, security vulnerability is often cited as a leading barrier to cloud adoption.
Hybrid cloud adds complexity to security management because it requires management across multiple platforms, often without transparency or visibility into what is being managed where. Businesses often misunderstand where the responsibility lies for ensuring security, believing the cloud provider bears sole responsibility.
The following provides a basis for a sound hybrid cloud security strategy:
- Insist on a “shared responsibility” approach: Although the business is ultimately responsible for securing its data, services, and applications, it's important for businesses to choose vendors that view security as a shared responsibility. Choose cloud providers that incorporate security into their platforms, offer tools and partners that make security management easier, and work with customers to implement best practices.
- Use tools and processes designed for the cloud: Automation and secure DevOps practices help security professionals automate system checks and tests into deployments. Removing human error from the workflow helps simplify development and deployment.
- Manage access: Identity and access management (IAM) frameworks help protect valuable assets from getting into the wrong hands. Policies should promote the concept of least-privileged access so that users only have access to the resources they absolutely require for their roles.
- Ensure visibility and define ownership: Management systems should help enterprises monitor and manage across multiple cloud platforms. Internal security teams should know who is responsible for specific assets and data and have robust communications plans in place so nothing is overlooked.
Hybrid cloud and IBM Cloud
IBM Cloud supports the most complete range of hybrid cloud uses cases—not just IBM public cloud and private clouds, but across multicloud environments.
Learn how IBM Hybrid Cloud solutions can ensure maximum flexibility and portability of your new and existing applications. Create an integrated environment that embraces public and private cloud platforms and offers supporting technologies for integration and multicloud management.
Sign up for an IBM ID and create your IBM Cloud account.