Cloud Deployment Models

Cloud Deployment Models

  • Cloud deployment models define where cloud resources are hosted and who has access to them
  • Four primary models exist, each with distinct ownership, location, and access characteristics
  • Choice depends on security requirements, compliance needs, cost considerations, and control preferences

Public Cloud

  • Cloud services delivered over the public internet by third-party providers (AWS, Azure, Google Cloud)
  • Resources are shared among multiple tenants but logically isolated
  • Provider owns and maintains all infrastructure, hardware, and software
  • Pay-as-you-use model reduces capital expenditure but increases operational costs
  • Best for: Development environments, web applications, backup storage, non-sensitive workloads
  • Security responsibility is shared between provider (infrastructure) and customer (data/applications)

Advantages:

  • Low upfront costs and rapid scalability
  • No hardware maintenance or facility management
  • Global availability and built-in redundancy

Disadvantages:

  • Limited customization and control
  • Potential compliance issues for regulated industries
  • Internet dependency for access

Private Cloud

  • Dedicated cloud infrastructure for a single organization
  • Can be hosted on-premises, by third-party provider, or in colocation facility
  • Organization maintains full control over security, compliance, and customization
  • Higher costs due to dedicated resources and management overhead
  • Best for: Financial services, healthcare, government agencies with strict compliance requirements
  • Complete control over data location, security policies, and resource allocation

On-Premises Private Cloud:

  • Located in organization’s own data center
  • Maximum control but highest cost and complexity
  • Requires dedicated IT staff for management

Hosted Private Cloud:

  • Third-party manages infrastructure at their facility
  • Reduces management burden while maintaining isolation
  • Example: Dedicated AWS instances or Azure dedicated hosts

Hybrid Cloud

  • Combines public and private cloud environments with orchestration between them
  • Allows data and applications to move between environments as needs change
  • Critical workloads remain in private cloud while less sensitive operations use public cloud
  • Requires robust connectivity (VPN, direct connections like AWS Direct Connect)
  • Best for: Organizations with varying security requirements, seasonal workloads, disaster recovery

Common Use Cases:

  • Cloud bursting: Handle peak loads by expanding to public cloud
  • Data sovereignty: Keep sensitive data private while using public cloud for processing
  • Gradual migration: Move workloads incrementally from private to public cloud

Technical Requirements:

  • Consistent networking and security policies across environments
  • Identity management integration (single sign-on)
  • API compatibility for workload portability

Community Cloud

  • Shared cloud infrastructure for organizations with common requirements
  • Multiple organizations share costs and resources while maintaining separation
  • Often industry-specific (healthcare, education, government)
  • Can be managed internally by community members or external third party
  • Best for: Industry consortiums, government agencies, research institutions
  • Compliance requirements are typically the driving factor for adoption

Examples:

  • Government community clouds (AWS GovCloud, Azure Government)
  • Healthcare clouds with HIPAA compliance
  • Financial services clouds with regulatory compliance

Comparison Table

Model Ownership Cost Control Security Scalability
Public Provider Low Limited Shared High
Private Organization High Full Organization Medium
Hybrid Mixed Medium Partial Mixed High
Community Shared Medium Shared Community Medium

Vocabulary

Multi-tenancy: Multiple customers sharing the same physical infrastructure while maintaining logical separation

Cloud Bursting: Automatically scaling from private to public cloud during peak demand periods

Data Sovereignty: Legal requirement that data remains within specific geographic boundaries

Orchestration: Automated coordination of cloud services and resources across multiple environments

Service Level Agreement (SLA): Contract defining expected service performance and availability metrics

Notes

  • Hybrid cloud is most complex to implement due to integration challenges between different environments
  • Public cloud appears cheaper but costs can escalate quickly without proper monitoring and governance
  • Private cloud doesn’t automatically mean more secure - security depends on implementation and management
  • Community clouds are less common but growing in regulated industries where shared compliance costs make sense
  • Consider data gravity - applications tend to move toward where the most data resides, affecting deployment decisions
  • Network connectivity becomes critical in hybrid deployments - plan for adequate bandwidth and redundancy
  • Cloud deployment model can change over time as business requirements evolve (cloud migration strategies)