Hybrid cloud architecture allows a company to combine a tightly controlled on-premise infrastructure with the power of a public cloud service. Due to high levels of flexibility, hybrid cloud solutions are the go-to option for modernizing existing and legacy applications.

This article is an introduction to hybrid cloud architecture. Read on to learn how companies set up hybrid systems to achieve technical and business goals more effectively than with a public or private cloud alone.

Hybrid cloud architecture explained

Hybrid Cloud Architecture Explained

Hybrid cloud architecture is a mix of two or more different types of infrastructure (public, private, community clouds, bare metal, etc.) bound together into a single system with total workload and data portability. These architectures vary based on business needs, but the most common systems combine:

  • An on-premises system (bare metal or private cloud) with a public cloud.
  • A public cloud, private cloud, and bare metal infrastructure.
  • Two or more private clouds.
  • Two or more public clouds.

Our comparison between public and private clouds highlights the main differences between the two most common cloud deployments.

Regardless of the specific setup, every hybrid cloud architecture has four traits in common:

  • Network connection: Different environments in a hybrid cloud share the same connections, either within a private network or via the Internet.
  • Full integration: Data and workload synchronization occurs across every component of a hybrid cloud.
  • Unified management: The team handles a hybrid setup through a single tool, and each environment uses the same operating system.
  • Quick resource provisioning: A hybrid cloud can swiftly provision new resources, typically via a third-party public cloud.

The connection between different components is the main feature of a hybrid cloud. A hybrid offers a unified cloud computing system that allows admins to move services between the environments.

If there is no integration between components, a company does not have a hybrid system. Instead, the setup runs several clouds in parallel and is likely a form of multi cloud.

Learn the difference between multi and hybrid cloud, two similar deployment models that lead to entirely different IT environments.

Three main aspects of designing a hybrid architecture are connectivity, app modernization, and cloud security.

Hybrid cloud architecture examples

Connectivity

Connectivity and interoperability are core concepts of a hybrid cloud architecture. This feature allows:

  • Free movement of workloads.
  • Unification of management.
  • Orchestration of processes.

The level of connectivity directly impacts how well the hybrid cloud works. To help you understand the importance of interconnectivity in a hybrid environment, we will use an example of an application for trading and storing stocks. As shown on the diagram below, the app relies on a private and public cloud.

Connectivity in hybrid cloud architecture

When someone accesses our example app, the user hits an endpoint on a private cloud and feeds into the on-prem Kubernetes cluster. The cluster contains numerous services:

  • The front end of the app (the UI).
  • The MQ service that enables the message queuing capability.
  • The portfolio service that allows users to manage investments.

The portfolio runs operations in the private cloud, but the service also relies on tasks in the public cloud. The central service in the public cloud is the one that fetches stock prices from the Investors Exchange (IEX).

The MQ service keeps track of the user loyalty levels. This service also requires access to the public cloud and notifies users in real-time about changes in their loyalty status or portfolio.

Our app requires high levels of interconnectivity between the private and the public cloud to work correctly. The workloads flow between environments, and the whole system operates as a single entity. The connection between the private and public cloud is vital, and we can connect the two via VPN, WAN, or an API.

Not sure whether the cloud is the right option for your use case? Our comparison of on-premise and cloud computing will help you choose the right approach.

Application Modernization

Modernizing monolithic apps and moving them to the cloud is among the biggest challenges of hybrid cloud adoption.

Let us say that our stock trader app began as a monolithic, on-prem system. The app was Java-based and had the same services as in the public-private cloud setup above:

  • The UI.
  • The portfolio service.
  • MQ service.
  • A connection to the IEX.
  • An on-premise database.

App monolith

At some point, architects had to break our fictional app apart and deploy it to the cloud to prevent user latency.

App deconstruction starts with deciding what pieces you want to break out of the monolith and deploy to the cloud. Some components are better options than others. In our example, deploying the portfolio to the cloud would lead to many unnecessary network hops and even worse latency.

Moving the UI to the cloud is a good option. As latency is the main issue, deploying the app’s front end to multiple locations can lead to a better user experience.

Once you know what piece will go to the cloud, the next step is refactoring. Architects need to create glue code that allows the app to keep the communication pathway between services. Once we refactor the UI, we can deploy the service to the public cloud. We direct only a small percentage of users to the cloud while we test the new flow.

Refactoring in hybrid cloud architecture

Once the public cloud setup is error-free, we can deprecate the old UI portion and start using the cloud for all traffic. Now we can begin thinking about what other services we can migrate and expand our hybrid cloud architecture.

Hybrid Cloud Security

Cloud security in a hybrid system is challenging as the team needs to protect different environments and the data moving between them. There are two major security concerns when designing a hybrid cloud architecture:

The starting point is to determine the cloud security risks that come with your north-south and east-west network traffic. North-south traffic is any activity traveling from end-uses to data centers or cloud environments. East-west traffic is the data flowing between hybrid cloud components.

Hybrid cloud architecture security

Perimeter security is crucial to any hybrid cloud architecture with on-prem components. Whether you are running a bare-metal data center or a private cloud, ensure that the perimeter has:

Public cloud security is primarily the provider’s responsibility, but the client also plays a part. For example, if you have a Kubernetes worker with multiple services set up in the cloud, fine-tuning the component’s endpoint security and request authentication is the client’s responsibility.

Securing east-west traffic in a hybrid cloud architecture requires you to ensure safe communication between environments. Network segmentation is a good tactic for protecting east-west traffic. Create strict policies that limit what segments users, admins, and processes can access.

In a Kubernetes environment, micro-segmentation requires you to set up TLS certificates for requests going between microservices. Encrypt requests and data (both in-flight and at rest) as early in their lifecycle as possible. Another Kubernetes best practice is to set up an admission controller that adds further levels of verification after initial authentication.

Learn how to create an effective cloud security policy, a crucial aspect of protecting your cloud environments.

Types of Hybrid Cloud Architecture

As private clouds are one-of-a-kind, and every public cloud provider offers different services, there are no one-size-fits-all hybrid solutions. However, every hybrid cloud corresponds to one of two primary types: traditional and modern hybrid cloud architecture.

Types of hybrid cloud architecture

Traditional Hybrid Cloud Architecture

Traditional hybrid cloud architecture focuses on transforming data centers into private clouds. Once the on-prem setup is ready, the team designs a connection with a public cloud to create a seamless workload and data flow. This unified IT infrastructure is ideal if:

  • The organization needs to keep sensitive data in a private cloud due to regulatory concerns.
  • The company wishes to migrate to the cloud to enhance legacy apps and improve performance.
  • The team wants to lift and shift existing on-prem workloads to a public cloud to reduce the data center footprint.
  • The business wishes to migrate inconstant workloads to the public cloud.
  • The team wants to use the public cloud to quickly spin up development and testing resources (an ability vital to efficient DevOps teams).

Typically, traditional hybrid cloud architecture relies on a prepackaged solution or enterprise-grade middleware that integrates cloud resources across environments. A central console and unified cloud monitoring tools keep the setup in good health.

Modern Hybrid Cloud Architecture

Modern hybrid cloud architecture focuses less on connectivity between components and more on the portability of workloads. That way, the system can seamlessly use the best environment for any task.

This type of hybrid cloud architecture allows organizations to leverage cloud-native technologies and use microservices to break apps into smaller, reusable components. Microservices ensure consistent and reliable deployment, management, and performance across different clouds and vendors.

In modern hybrid cloud architecture, the lines between public and private clouds are less distinct. Many providers now offer public cloud services that run in the client’s on-premise data center. Private clouds, which traditionally run on-premises, can now operate:

  • In an off-premises data center.
  • On virtual private networks (VPNs).
  • As a virtual private cloud (VPC).

Infrastructure-as-code (IaC) is a significant aspect of modern hybrid cloud architecture. IaC allows developers to spin up new environments quickly and on-demand.

Designing and Building a Hybrid Cloud Architecture

Before designing a hybrid cloud architecture, consider the checklist below to ensure your plan does not run into any pitfalls.

Hybrid cloud architecture deciding factors

Consider Simpler, Less Expensive Deployment Models

A hybrid cloud relies on complex integration between different environments, making the setup an ideal fit for high-volume workloads and distributed systems. If your app does have intense workloads and does not need flow overlap, deploying a simpler cloud model might be a better option.

Once the app and its user base grow, start thinking about expanding to a hybrid cloud to maintain performance levels.

Our article about the different cloud deployment models helps identify the right option for your use case.

Make an In-Depth Plan for Your Workloads

Start designing the architecture by determining how and where each workload will run. This plan requires a delicate balance between:

  • In-house accessibility needs.
  • Compliance requirements.
  • Application needs.

Consider the following factors when planning which environment to use for each workload:

  • Security levels.
  • Legal obligations.
  • Service price.
  • Accessibility.
  • App requirements.
  • User locations.

If your company processes sensitive data, plan where you will store that info and what systems will have access to valuable data. Also, consider if some legacy systems will be unable to operate correctly in a cloud environment.

Be Wary of Vendor Lock-In

Building a hybrid cloud on a platform that cannot handle your workloads can create expensive problems in the future.

Teams looking for a SaaS partner have a bigger margin for error, but companies that want to build an app through a PaaS or IaaS provider must make the right choice from the start to avoid serious vendor lock-in issues. When choosing your cloud service provider, consider the following:

  • Service cost.
  • Used technologies.
  • Management tools.
  • Physical locations of data centers.
  • Service-level agreements (SLAs).
  • Support for bare-metal and private cloud environments.
  • Security, governance, and business policies.
  • Service dependencies.

Understand the difference between IaaS, PaaS, and SaaS, three of the most common types of cloud services.

Pick the Right Cloud OS

A cloud operating system enables a team to monitor and manage a hybrid environment through a single set of tools. Cloud OS should simplify management and grant agility, so choose the software that fits your developers’ needs. Some of the most popular options are:

Choose the cloud OS based on what tool offers the right data management approach. Ideally, the OS should not require you to retrain the entire IT staff.

Build Security into Your Hybrid Cloud Architecture

Treat security controls and policies as a fundamental piece of your hybrid cloud architecture. Security should not be an afterthought, so ensure proper protection levels are a building block for every environment.

Start thinking about cybersecurity risks as early in the design process as possible. DevSecOps is a good approach when building cloud systems if you wish to think about security from the ground up.

An Ideal Cloud Option for Application Modernization

Hybrid cloud architecture allows a company to modernize its apps by connecting clouds to existing IT infrastructure. This approach makes hybrid clouds an ideal option for any company that wishes to use cloud computing while keeping tight control over its IT setup.