AZ-900 Certification Notes

Chapter 2 - The Language of Cloud Computing

Terms

• High availability
  • Traditional:
    • You own the hardware
    • You have physical access
    • You can't "just add servers"
  • Cloud:
    • You don't own the hardware
    • Add more servers with a click
    • If hardware fails, replace it instantly
    • Use clusters to ensure high availability
• Scalability
  • Automatically adjust resources to meet demand
    • Example: Increase the number of VMs to handle peak traffic
  • Don't overpay for services
    • Automatically reduce resources when demand drops
  • Horizontal vs. Vertical Scaling
    • Horizontal = Adding additional VMs/containers
      • "Scaling out"
    • Vertical = Increasing power (e.g., CPU/RAM) of existing VMs
      • "Scaling up"
    • 'Typical' cloud model = Horizontal scaling
• Predictability
  • Predictable Performance and Costs
    • Performance
      • Consistent experience for customers regardless of traffic
      • Autoscaling, load balancing, and high availability provide a consistent experience
    • Costs
      • No unexpected surprises
      • Track and forecast resource usage (costs) in real time
      • Analytics provide patterns/trends to optimize usage
• Reliability
  • Resilience
    • The ability of a system to recover from failures and continue to function
  • Deploy in Multiple Locations
    • Global-scale computing
    • Protects against regional failure/disaster
  • No Single Point of Failure
    • Resources in multiple locations
    • If one computer goes down, others pick up the load
• Security
  • Full control of the security of your cloud environment. Patches, maintenance, network control, and more.
• Governance
  • Standardize environments
  • Regulatory requirements
  • Audit for compliance
• Manageability
  • Management of the cloud:
    • Autoscaling
    • Monitoring
    • Template-based deployments
  • Management in the cloud:
    • Portal
    • CLI
    • APIs

Exam Tips

Cloud computing has terms that are specific and critical to understanding it

• High availability means systems are always available -- even automatically.
• Reliability describes how Azure can tolerate failures or even disasters.
• Scalability refers to scaling out or scaling up while automatically providing resources as needed.
• Predictability is knowing your application will always perform as expected and knowing what it will cost.
• Security is having full control of your cloud security posture.
• Governance is standardizing cloud deployments to meet requirements/company standards.
• Manageability is management of cloud resources and how we interact with them.