Cloud Services Lecture Notes

Key Objectives

• Understand the Shared Responsibility Model
• Describe different categories of cloud services:
  • Infrastructure as a Service (IaaS)
  • Platform as a Service (PaaS)
  • Serverless Computing
  • Software as a Service (SaaS)

Shared Responsibility Model

• Customer vs. Provider Responsibilities
  • Responsibilities vary depending on the service type.
  • Different service layers: storage, networking, compute, hypervisor, operating system, runtime, application, data.
  • Differentiation and innovation focus on application and data.

Infrastructure as a Service (IaaS)

• Description: VM in the cloud.
• Provider Responsibilities: Physical fabric, storage, network, compute, hypervisor.
• Customer Responsibilities: Operating system, runtimes, application, data.
• Benefits: High flexibility and control.
• Challenges: High responsibility including patching, antivirus, backups.

Platform as a Service (PaaS)

• Description: Focus on app and data without managing VMs.
• Provider Responsibilities: All infrastructure including operating systems and runtimes.
• Customer Focus: Application and data.
• Benefits: Reduced responsibility, but less flexibility.
• Examples: Azure Kubernetes Services, Azure App Services.

Serverless Computing

• Description: No visible infrastructure; pay for work done.
• Characteristics:
  • Event-driven execution.
  • Pay-per-execution model.
• Examples: Azure Functions, Logic Apps.
• Benefits: Maximizes efficiency by only paying for execution cycles and memory used.

Software as a Service (SaaS)

• Description: Complete business solution delivered.
• Provider Responsibilities: Entire application management and maintenance.
• Customer Responsibilities: Minimal, often only basic admin tasks.
• Examples: Microsoft 365, Salesforce.
• Benefits: Provides business value with no infrastructure management.

Choosing a Cloud Service Strategy

• Maximize Efficiency: Prefer SaaS > PaaS > IaaS based on needs.
• Considerations:
  • Use SaaS if available and sufficient.
  • Opt for serverless or PaaS to minimize operational responsibilities.
  • Use IaaS for legacy or specific control needs.
• Goal: Minimize operational burden while focusing on application and data value.