Cloud Computing mainly has three deployment models namely Private, Public, and Hybrid cloud. A public cloud is a cloud deployment model in which cloud resources are offered over the internet and open to all users and organizations. The public cloud is a major deployment model used today. Adopting the public cloud is more cost-effective as third-party providers manage the resources. Let us understand the public cloud in detail in this article.
Public Cloud Architecture & Global Infrastructure
Top-tier providers like AWS, Azure, and Google Cloud do not rely on a single server. Their architecture is built for Fault Tolerance:
- Regions: Geographic areas (e.g., US-East, Europe-West) containing multiple data centers.
- Availability Zones (AZs): Isolated locations within a region. If one data center catches fire, your data instantly flips to another AZ in the same region.
- Edge Locations: Small cache sites located near users to deliver content (like Netflix videos) faster.
Working Of Public Cloud
A public cloud is a widely used cloud computing model where companies and individuals can access services like storage, applications, and virtual machines over the internet. These services are provided by third-party companies and are available to anyone who subscribes or pays for them. Here's an easy breakdown of how it works:
1. Infrastructure and Ownership
- Provider-Owned Systems: Companies like Amazon Web Services (AWS), Microsoft Azure, and Google Cloud own and manage the entire setup, which includes data centers, servers, networking equipment, and software.
- Shared Resources: Users share the infrastructure (like servers and storage) with others, but their data and activities are securely separated. This shared setup, called multi-tenancy, ensures cost efficiency while maintaining privacy.
2. Service Delivery
Public cloud services are delivered via the Internet and fall into three main categories:
- Infrastructure as a Service (IaaS): Offers basic computing resources like virtual machines, storage, and networks. Users control the software they install on these virtual systems (e.g., AWS EC2, Google Compute Engine).
- Platform as a Service (PaaS): Provides tools for developers to build and deploy apps without worrying about managing the underlying hardware or operating systems (e.g., Google App Engine, Azure App Service).
- Software as a Service (SaaS): Ready-to-use software applications that are accessible online, like Google Workspace, Microsoft 365 or Salesforce.
The Shared Responsibility Model (Security)
A common misconception is that the "Cloud Provider handles all security." In reality, it is a partnership:
- Security OF the Cloud (Provider’s Job): Protecting the physical servers, cables, and the software that runs the virtualization.
- Security IN the Cloud (Your Job): Managing your passwords (IAM), encrypting your data, and configuring firewalls (Security Groups).
Pro-Tip: Always implement IAM (Identity and Access Management). It ensures that only the right people have the "keys" to specific parts of your cloud infrastructure.
Difference between Private, Public and Hybrid cloud
Private Cloud | Public Cloud | Hybrid Cloud |
|---|---|---|
Private cloud infrastructure is hosted by organization and it is isolated for outside access. | Public cloud infrastructure is hosted by third party service provider which can be access by any public user. | Hybrid cloud consists of infrastructure which is hosted in public and private cloud model. |
Infrastructure is completely managed by organization recurring cost. | Infrastructure is managed by third party provider making users only pay for the resource usage. | Infrastructure is maintained by both organization and provider making flexible cost. |
More security and control over data as infrastructure is isolated to organization. | Security is managed by third party provider and less control over data as data is stored as providers infrastructure. | Flexible for storing data and managing security. |
More usage cost as resources has to be managed on own. | Less usage cost as users have to only pay for what they use. | Cost occurs for private infrastructure while public infrastructure is less costly. |
Limited in terms of scalability as limited infrastructure. | Highly scalable as more resources are available. | Scalable due to implementation of both models. |
Availability depends on infrastructure locality | More availability as infrastructure is mostly spread across various regions. | Allows high availability because of private and public infrastructure. |
Security Considerations in Public Cloud
Security in public cloud is shared responsibility for user and provider. To maintain the best security of data and infrastructure following methods can be used :
- Data can be segregated and isolated with the help of security policies to avoid unauthorized access.
- IAM can be implemented for roles, permissions and authorization is public cloud which provides granular security over infrastructure.
- Ensure Cloud service provider has good patch management and updating of cloud infrastructure allowing security from latest malware and viruses.
- Network security can be maintained by both CSP and User with the help of Security Groups, Firewalls and NACLs.
How can AWS supports public cloud requirements ?
AWS is one of the major cloud service provider which offers public cloud environments with high availability and scalability.
- Aws offers global infrastructure which is spread across globe. It is divided by regions which have multiple datacenters.
- AWS offers cost effective pricing for usage and allows nearly zero downtime infrastructure.
- It offers various Infrastructure services like Compute, Storage , Database , Networking and Other Services which can be used by user.
- It offers best security and fault tolerance by implementation of latest security standards and protocols within infrastructure.
Advantages of Public Cloud
- No Maintenance: You never have to swap a broken hard drive or pay for electricity for a server room.
- Agility: You can launch 1,000 servers in 5 minutes and turn them off 10 minutes later.
- Reliability: Providers offer 99.99% (the "Four Nines") uptime guarantees.
Disadvantages of Public Cloud
- Vendor Lock-in: Moving a massive database from AWS to Azure can be difficult and expensive.
- Internet Dependency: If your internet goes down, your access to the "office" goes down.
- Strict Regulation: Some industries (like high-level government) are legally forbidden from storing data on public hardware.
Common Use Cases
- Software Development: Spinning up "disposable" environments for testing code.
- Big Data Analytics: Using the cloud’s massive CPU power to analyze millions of records in seconds.
- Backup & Disaster Recovery: Keeping a cheap copy of your data in a different geographic region.
- Web Hosting: Running websites that can handle sudden spikes in traffic (like Black Friday sales).