Cloud Deployment Models

What is a Cloud Deployment Model?

Cloud deployment refers to:

How you distribute your cloud computing resources such as "compute", "storage", "database" etc in terms of ownership, accessibility, and management.
It also defines, how cloud services or infrastructure are deployed and made available to users or organizations

Three very popular cloud deployment models

Public Cloud (Cloud)
Private Cloud (On-Premise)
Hybrid Cloud (Public+Private)

Public Cloud

Definition:

A cloud-based application is fully deployed in the cloud and all parts of the application run in the cloud.
Applications are either created in the cloud or migrated from existing infrastructure to leverage cloud computing benefits.

Ownership:

All hardware, software, and supporting infrastructure are owned and managed by the cloud provider.
You share the same hardware, storage and network devices with other organizations or cloud “tenants”.

Accessibility:

Publicly accessible by multiple users and organizations over the Internet.

Scalability:

Highly scalable, resources can be easily scaled to meet your demanding needs.
Cloud resources such as compute (EC2) can be dynamically increased or decreased based on demand.

Cost:

Pay-as-you-go model: You pay for what you consume
Cost-efficient especially for start-ups and small businesses

Advantages:

Lower costs: no need to purchase hardware or software and you pay only for the service you use.
No maintenance: The cloud service provider provides the maintenance.
Near-unlimited scalability: on-demand resources are available to meet your business needs.
High reliability: a vast network of servers ensures against failure.

Examples:

Amazon Web Services (AWS), Microsoft Azure, Google Cloud

Private Cloud

Definition:

Cloud Offering that is created and owned by the same organization
Cloud offering that is dedicated to single/same organization.
The infrastructure is provisioned on the organization's premises but may be hosted in a third-party data center. In most cases, a private cloud infrastructure is implemented and hosted in an on-premise data center using a virtualization layer

Ownership:

Private Cloud is managed and owned by the organization itself

Accessibility:

Restricted access, limited to a specific organization

Scalability:

Scalability depends on the organization's infrastructure

Cost:

Higher upfront costs and maintenance expenses
Private Clouds are more expensive than Public Cloud due to the capital expenditure involved in building and maintaining the infrastructure.

Advantages:

Private cloud address the security and privacy concerns raised in public cloud offerings.

Examples:

Open Stack, Azure Stack

Hybrid Cloud

Definition:

Hybrid Clouds combine on-premises infrastructure, or Private Cloud, with Public Cloud
Its combination of public and private cloud infrastructure

Ownership:

Both Public and Private Clouds are used, Private Cloud ownership lies with organizations while Cloud Providers maintain the ownership of Public Cloud

Accessibility:

Accessible to multiple users and organizations

Scalability:

Scalability can be achieved by leveraging both environments

Cost:

Costs vary depending on the mix of public and private usage

Advantages:

Make the best of Public Cloud scalability and reliability features while maintaining security controls within the organization

Examples:

AWS Outposts, Microsoft Azure Hybrid Cloud, Google Anthos

Common Use Cases:

you might have legacy applications that are better-maintained on-premises, or government regulations require your business to keep certain records on premises
Data Center Extension: Extending an organization's infrastructure into the cloud while connecting cloud resources to the internal system.
VMware Cloud on AWS: is an integrated cloud offering delivering a scalable, secure and innovative service that allows organizations to seamlessly migrate and extend their on-premises VMware vSphere-based environments to the AWS Cloud running on next-generation Amazon Elastic Compute Cloud (Amazon EC2) bare metal infrastructure.

Let's Summarize

Attribute	Public Cloud	Private Cloud	Hybrid Cloud
Definition	A cloud-based application fully deployed in the cloud with shared resources among multiple users and organizations.	Cloud offering dedicated to a single organization, hosted on-premise or in a third-party data center using a virtualization layer.	Combination of public and private cloud infrastructure, offering both on-premises and cloud resources.
Ownership	All hardware, software, and supporting infrastructure are owned and managed by the cloud provider.	Managed and owned by the organization itself.	Public Cloud is owned by providers, and Private Cloud is owned by organizations.
Accessibility	Publicly accessible by multiple users and organizations over the Internet.	Restricted access, is limited to a specific organization.	Accessible to multiple users and organizations.
Scalability	Highly scalable, resources can be easily scaled based on demand.	Scalability depends on the organization's infrastructure.	Scalability is achieved by leveraging both environments.
Cost	Pay-as-you-go model, cost-efficient for start-ups and small businesses.	Higher upfront costs and maintenance expenses.	Costs vary depending on the mix of public and private usage.
Advantages	Lower costs, no maintenance, near-unlimited scalability, and high reliability.	Addresses security and privacy concerns, and more control over resources.	Utilizes best of public cloud scalability while maintaining security controls.
Examples	Amazon Web Services (AWS), Microsoft Azure, Google Cloud.	Open Stack, Azure Stack.	AWS Outposts, Microsoft Azure Hybrid Cloud, Google Anthos.
Common Use Cases	Applications fully in the cloud, cost-efficient scalability.	Legacy applications and regulatory compliance.	Data center extension, VMware Cloud on AWS.