What is Hybrid Cloud? A Complete Guide to Models, Architecture and Future Trends

Hybrid cloud refers to an integrated cloud computing environment that connects infrastructure and services between cloud providers and on-premises data centers. Organizations adopt hybrid cloud strategies to optimize efficiency, costs, security and performance by blending the advantages of private and public clouds.

This comprehensive guide provides an overview of hybrid cloud fundamentals, architectural considerations, use cases, management best practices and an outlook on the future of this increasingly popular model.

What is Hybrid Cloud?

A hybrid cloud environment comprises:

  • Private cloud platforms like VMWare or OpenStack providing dedicated infrastructure for internal workloads
  • Public cloud services like AWS, Azure and GCP for scalable computing and storage
  • On-premises legacy infrastructure for performance-sensitive systems and regulated data
  • Orchestration between environments to enable workload mobility and flexibility

Hybrid cloud provides the most agile and optimized IT infrastructure by converging services from multiple cloud platforms and models.

Organizations choose hybrid cloud to benefit from both public and private environments while balancing critical considerations around security, compliance, costs and capability.

According to Flexera‘s 2021 State of The Cloud Report, 87% of enterprises now have a multi-cloud strategy with most utilizing a hybrid model.

Cloud Computing Models Compared

Fundamentally, there are three types of cloud computing models in use today:

Public Cloud

Cloud platforms that provide servers, storage, networking, middleware and services over the internet. Public cloud providers include AWS, Microsoft Azure, Google Cloud, IBM Cloud etc.

Pros – Extreme scalability and flexibility, consumption-based pricing, self-service capabilities

Cons – Lower control and visibility compared to private cloud, higher security risks

Private Cloud

Dedicated compute infrastructure provisioned for exclusive use by a single organization, located either on-premises or externally hosted.

Pros – Enhanced customization, security and control

Cons – Higher capital expenditure costs, limited flexibility due to fixed resources

Hybrid Cloud

As the name suggests, a hybrid approach combines public and private models together. Organizations can extend or shift workloads between environments to achieve optimal economy, scale and performance.

Pros – Balance of cost efficiency and tight control, flexibility to move workloads, disaster recovery benefits

Cons – Increased complexity to manage heterogeneous resources and connectivity

Types of Hybrid Cloud Setups

There are two primary types of hybrid cloud architectures:

Heterogenous Model

This setup integrates apps, data and cloud services between various public cloud platforms (Azure, AWS etc.) and disparate on-premises private cloud software/hardware combinations.

It provides maximum choice and flexibility to leverage specialized capabilities from different vendors. But also increases complexity of unified management.

Homogenous Model

This architecture adopts private/public cloud infrastructure from the same vendor or based on consistent standards. Examples include AWS Outposts, Azure Stack or VMware Cloud.

While simpler to manage, it reduces flexibility to choose best-of-breed platforms and limits integration with legacy non-compatible on-prem systems.

Additionally, there are three common hybrid design patterns in terms of application architectures:

Partially Integrated – Some workloads hosted on-premises, others migrated to the public cloud. Enables leveraging specialized capabilities of each environment.

Staged Migration – Smooth transition from private cloud and data centers to the public cloud over time. Gradual shift reduces risk and cost.

Fully Integrated – Apps distributed across public and private clouds but interoperating as a unified environment via middleware integrations. Best leverage of combined resources.

Hybrid Cloud Architecture and Interconnectivity

The key technical challenge in hybrid cloud is establishing seamless orchestration between disparate environments. This requires:

Integrated Networking – Private clouds, like Azure Stack or AWS Outposts, connect to public cloud data centers through dedicated high-speed links like AWS Direct Connect for robust interconnectivity.

APIs and Management Tools – Platform consistent APIs (like VMware hybridity toolsets) simplify control and monitoring of infrastructure across environments, on-prem and the public cloud.

Data Access Controls – Applying fine-grained permissions and security protocols onto communication interfaces between all connected cloud components and legacy systems.

Service Mesh – Middleware integrations using containerization/microservices enable uniform policy controls, observability and traffic routing regardless of where application elements are hosted.

Here is an overview of a common hybrid infrastructure spanning private cloud, virtualized on-premises systems and IaaS as well as PaaS public cloud services:

Hybrid Cloud Architecture

And this is what a real-world deployment can look like connecting AWS VPCs and Direct Connect with an on-premises VMWare private cloud data center:

AWS Hybrid Cloud

Managing Hybrid Cloud Environments

While the flexibility of hybrid cloud delivers substantial business value, it significantly ramps up infrastructure complexity that IT teams must cope with.

Some key challenges include:

  • Maintaining consistent visibility, controls and governance across diverse resources
  • No unified view of asset inventory, utilization and spend analysis
  • Platform inconsistencies hampering workload mobility
  • Integrating siloed monitoring/alerting leading to tool sprawl
  • Lack of common automation and provisioning procedures

Establishing robust management practices is essential to smooth hybrid cloud operations:

  • Define policies, roles and approval workflows upfront aligned to compliance needs
  • Implement access controls, identity management and auditing consistently across environments
  • Standardize configurations using version controlled templates and infrastructure-as-code
  • Streamline monitoring by aggregating metrics/logs into unified dashboards
  • Integrate service desk and change control processes between ops teams
  • Leverage automation and orchestration to simplify deployment and scaling

Additionally, adopting cloud management platforms (CMPs) can provide turnkey hybrid infrastructure visibility, governance and automation. Example CMP solutions include VMware vRealize Suite, Cisco Intersight and RedHat CloudForms.

Hybrid Cloud Use Cases and Examples

Hybrid environments uniquely cater to a diverse range of applications and workloads. Some examples include:

Cloud Bursting – Web properties like e-commerce sites rely on private cloud and data centers to manage traffic spikes by temporarily offloading excess demand onto the public cloud.

Data Gravity Migration – Slowly transitioning enterprise apps with terabytes of associated data from on-premises to public cloud without business disruption.

IoT Data Processing – Streaming high-velocity sensor data into the cloud while localized analytics and message queuing happens on-premises.

DevOps – Developer sandbox and test environments leveraging public cloud while tightly coupled line-of-business systems remain on legacy infra.

Disaster Recovery – Replicating performance sensitive databases into the public cloud to retain high availability during outages.

Regulated Workloads – Data sovereignty and compliance requirements dictate keeping customer PII, financial data within a private infrastructure while the public cloud handles backups, archives and analytics.

Every industry leverages hybrid advantages based on specific needs:

Healthcare – Patient records on-premises, imaging and diagnostics in the cloud

Financial Services – Transaction systems private, trade analytics and AI in the public cloud

Energy – Sensor data processing on-premises, exploration analytics in the cloud

Retail – Inventory private, web and mobile channels leveraging public cloud

Government – Citizen data repositories on-prem, elastic case management solutions in the public cloud

Securing The Hybrid Cloud

While hybrid infrastructure provides greater flexibility, it also escalates security risks across expanded perimeters and interfaces:

  • More exposure points between public cloud, private cloud and legacy systems
  • Users possibly bypassing security controls when accessing cloud SaaS apps
  • Inconsistent identity, access and compliance policies across environments
  • Limited visibility into abnormal behavior and threats across cloud and on-prem

Some best practices to lock down hybrid cloud include:

  • Unified identity, access and key management spanning all ecosystems
  • Fine-grained role-based access control (RBAC) aligned to zero-trust models
  • API and endpoint security plus data protection wherever hosted
  • Collective behavioral analytics identifying threats across cloud types
  • Automation to enforce standardized configurations continuously

Additionally, adopting cloud-delivered security platforms (CSPs) can simplify safeguarding heterogeneous hybrid environments via as-a-Service models:

Hybrid Cloud Security

Optimizing Hybrid Cloud Economics

A core driver for hybrid cloud adoption is achieving substantial cost savings and efficiency gains. Strategies to optimize spending include:

Tiered Storage – Automate placement of data across hot, warm and cold tiers based on access patterns

Reserved Instances – Up to 70% discounted compute capacity reservations in AWS/Azure

Spot/Preemptible Instances – Leverage transient serverless capacity up to 90% cheaper

Resource Scheduling – Shut down dev/test capacity overnight and weekends

Automated Rightsizing – Scale capacity up/down based on actuals with auto-scaling tools

Utilization Monitoring – Identify and eliminate waste from low efficiency resources

FinOps Frameworks – Platforms providing spend visibility, showback reporting and budget alerts

Challenges with Hybrid Cloud

While interest and adoption of hybrid cloud continues to steadily grow, some constraints remain around:

Data Gravity – "Stickiness" of data once accumulated in cloud storage makes transferring large volumes expensive and time-consuming

Vendor Lock-in – Platform inconsistencies hamper workload portability between different public clouds

Talent Shortages – 83% of organizations face hybrid cloud skills gaps around security, analytics and multi-cloud

Management Overhead – The overhead of integrating tools and processes across disparate platforms persists

Regulatory Barriers – Data sovereignty and privacy regulations applicable to local geographies can restrict storage flexibility

However, ongoing technology advancements by cloud providers like AWS and Azure continue to smoothen these rough edges through solutions like Outposts (bringing AWS on-prem) and consistency certifications enabling easier migration across cloud types.

The Future of Hybrid Cloud

Gartner predicts that by 2025, 90% of organizations will be relying on hybrid infrastructure to accelerate their digital business transformation.

Several trends are poised to shape the next generation hybrid cloud landscape:

Multi-Cloud – Using specialized combinations of niche clouds for AI, analytics and edge delivery coordinated via cloud-agnostic CMPs

Everything-as-a-Service – Consuming modular SaaS pieces like security, databases and app dev tools across environments

Edge Computing – Distributed micro data centers embedded at cellular towers, retail spaces etc. managed consistent with cloud resources

Automation Everywhere – AIOPS driving smarter insights and predictive issue resolution across cloud types

Containers and Microservices – Encapsulated app components enabling seamless portability across cloud types

In summary, a well-architected hybrid technology framework provides the most agile foundation to deliver efficiency alongside differentiation. Consistently evolving innovations will continue to smooth management overhead as hybrid becomes the dominant emergent enterprise architecture over the next decade.