Cloud Deployment Models

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A cloud deployment model classifies how a cloud service is owned and provisioned.

• define the specific architecture of cloud-based services
• models describe the technology, resources, locations of data, applications, and services a cloud provides

Models

Private Cloud

Private cloud is cloud infrastructure that is completely private to and owned by the organization.

• one business unit dedicated to managing the cloud,
  • other business units make use of it
• geared more toward banking and governmental services that require strict access control in their operations
• could be on-premises or off-site relative to the other business units
  • on-site link
    • can deliver better performance
    • is less likely to be subject to outages
  • dedicated off-site facility may provide better shared access for multiple users in different locations
• Benefits
  • greater control over the privacy and security of services
  • greater flexibility, scalability, agility
  • gain cost effectiveness of cloud without sharing resources
• Cons
  • require more up-front capital and ongoing maintenance than a public cloud

Hosted private is cloud infrastructure hosted by a third party for the exclusive use of one organization.

• aka single tenant
• more secure and can guarantee a better level of performance
  • more expensive

Public Cloud

Public cloud is deployed for shared use by multiple independent tenants.

• aka multitenant
• is a service offered by cloud service providers (CPSs) to cloud consumers (tenants)
• designed for public access
• As a shared resource, there are risks regarding performance and security
• services are hosted on a third-party infrastructure and accessed via the Internet
• e.g., Amazon AWS, Microsoft Azure, Google Cloud, Linode, IBM Cloud, Oracle Cloud, etc.

Cloud service provider (CSP) is an organization providing infrastructure, application, and/or storage services via an “as a service” subscription-based, cloud-centric offering

• can offer:
  • subscriptions
  • pay-as-you-go financing
  • lower-tier services free of charge
• oversubscription means that a cloud provider can sell customers a total capacity that exceeds the actual physical capacity of the infrastructure
  • customers will rarely use all the capacity simultaneously
    • if it does happen, causes performance slowdowns and outages

Multi-Cloud

Multi-cloud architectures are where the consumer organization uses services from more than one CSP.

• Benefits
  • can take advantage of service and price differences
  • reduced risk of reliance on sole provider
• Cons
  • added complexity

Community Cloud

Community cloud is where several organizations share the costs of either a hosted private or fully private cloud.

• done to pool resources for a common concern, such as standardization and security policies
• not open to public
• can be provisioned by a third party on behalf of members of a community
  • e.g., CSP offering FedRAMP cloud service for use only by U.S. federal gov customers

Hybrid

Hybrid cloud deployment uses elements of both public and private models.

• implements some sort of hybrid public/private/community
• E.g.,
  • travel organization may run a sales website for most of the year using a private cloud but “break out” the solution to a public cloud at times when much higher utilization is forecast
• may be used to provide some functions via a public cloud
  • but keep sensitive or regulated infrastructure, applications, and data on-premises
• companies can store data in a private cloud
  • but also leverage the resources of a public cloud when needed

Benefits

• greater flexibility and scalability
• cost savings
• allows for a smoother transition to the cloud for companies that may need more time to migrate all of their data
• can provide data redundancy features
  • e.g., replicating data across on-premises and cloud infrastructure
  • can achieve data protection
  • can also lead to issues with data consistency stemming from synchronization problems among multiple locations

Cons/Challenges

• presents security challenges
  • managing multiple cloud environments
    • complex
    • integrating them with on-premises infrastructure
      • can create security gaps
      • increase the risk of data breaches
  • enforcing consistent security policies across all environments
  • potential for unauthorized access to data and applications,
    • particularly when sensitive information is stored in the public cloud
  • often mistakes caused by confusion over the boundary between on-premises and public cloud infrastructure
• adds additional complexity to data governance and security operations
  • compliance applies to both environments
• challenging to establish SLAs
  • due to integration of different cloud and on-premises systems
• concerns related to the hybrid cloud include:
  • potential for increased network latency
    • due to large data transfer volumes between on-premises and cloud environments that impact application performance
  • monitoring the hybrid environment can be more complex
    • due to the requirement for specialized expertise and tools

Security Considerations

Different cloud architecture models have varying security implications to consider when deciding which one to use.

• Single-tenant architecture
  • provides dedicated infrastructure to a single customer, ensuring that only that customer can access the infrastructure
  • offers the highest level of security
    • customer has complete control over the infrastructure
  • can be more expensive than multi-tenant architecture
  • customer is responsible for managing and securing the infrastructure
• Multi-tenant architecture
  • multiple customers share the same infrastructure, with each customer’s data and applications separated logically from other customers
  • cost-effective
  • can increase the risk of unauthorized access or data leakage if not properly secured
• Hybrid architecture
  • uses public and private cloud infrastructure
  • provides greater flexibility and control over sensitive data and applications
    • by allowing customers to
      • store sensitive data on private cloud infrastructure
      • while using public cloud infrastructure for less sensitive workloads
  • requires careful management to ensure proper integration and security between the public and private clouds
• Serverless architecture
  • cloud provider manages the infrastructure and automatically scales resources up or down based on demand
  • can be more secure than traditional architectures
    • cloud provider manages and secures the infrastructure
  • customers must secure access to their applications and data