Table of Contents
Introduction to Cloud Computing for AZ-900
There are different cloud computing concepts are required for AZ 900 Certification. The overall weightage of this is about 20%
Core Characteristics of Cloud Computing
Scalability
Scalability in cloud computing refers to the ability to increase or decrease resources based on demand.
- Vertical Scaling: Adding more power (CPU, memory) to an existing machine.
- Horizontal Scaling: Adding more instances of machines to handle load.
Elasticity
Elasticity is the capability to automatically scale resources up or down based on usage patterns. It ensures optimal performance without manual intervention.
Agility
Cloud agility allows businesses to respond quickly to changes. Resources can be provisioned or de-provisioned in seconds, unlike traditional systems that take days or weeks.
Agility is the ability to allocate and deallocate(Scale) resources quickly
| Cloud | On-Prem |
| Seconds | Days |
| Minutes | Weeks |
| Hours | Months |
Fault Tolerance
A fault-tolerant cloud system continues to operate even when components fail. This ensures continuous availability and minimal service disruption.
Disaster Recovery
Disaster recovery is the process of restoring services after an outage or disaster, whether due to hardware failure, human error, or natural calamities.
High Availability
High availability ensures maximum uptime.
Formula: Availability = Uptime / (Uptime + Downtime)
Cloud systems are designed for redundancy and failover to keep services accessible.
Understanding Cloud Economics: CapEx vs OpEx
Capital Expenditure (CapEx)
Key Characteristics
- Invests in physical infrastructure
- Requires significant upfront costs
- High maintenance and staffing requirements
Operational Expenditure (OpEx)
Key Characteristics
- Pay-as-you-go model
- Minimal upfront investment
- Reduced maintenance and support needs
Differences
| Characteristics | CapEx | OpEx |
| Upfront cost | Significant | None |
| Ongoing Cost | Low | Based on Usage |
| Tax Deduction | Over time | Same year |
| Early Termination | No | Anytime |
| Maintenance | Significant | Low |
| Value over time | Lowers | No change |
Consumption-Based Pricing Model
Key Characteristics
- No upfront investment
- Charges based on actual usage
- Services billed per compute, storage, and network usage
- Highly granular billing metrics
Cloud Service Models: IaaS, PaaS, and SaaS
Infrastructure as a Service (IaaS)
You manage: OS, middleware, runtime, data, applications
Provider manages: Networking, storage, servers, virtualization
Use Cases: VM hosting, test environments, backups
Platform as a Service (PaaS)
You manage: Applications and data
Provider manages: Infrastructure and platform
Use Cases: App development, analytics, BI tools
Software as a Service (SaaS)
Provider manages everything – from hardware to application
Use Cases: Email, CRM, productivity tools
Infrastructure → Storage – Networking – Server – Virtualization
Cloud Deployment Models
Public Cloud
Key Characteristics
- Everything runs in the cloud provider hardware.
- No local hardware
- Some Services share hardware with other customers
Advantages and Disadvantages
| Advantages | Disadvantages |
| No Capex | Security & Compliance |
| High availability & agility | Ownership |
| Security & Compliance | Specific scenarios with unique business requirements |
| No hardware maintenance | |
| No deep technical skills required |
Private Cloud
Key Characteristics
- Everything runs on your data center.
- Self-service should be provided
- You maintain the hardware
| Advantages | Disadvantages |
| Can support any scenario | Initial Capex |
| Control over security | Limited Agility |
| Can meet any security & compliance & requirements | IT skills expertise are mandatory |
Hybrid Cloud
Key Characteristics
- Combines public & private clouds
- Great Flexibility
| Advantages | Disadvantages |
| Great flexibility | Can be more expensive |
| Run legacy apps in a private cloud | Complicated to manage |
| Utilize existing infrastructure | IT Skills & Expertise are mandatory |
| Meet any security requirements |
Azure Geographies, Regions, and Availability Zones
Data Centers
Key characteristics
- Physical facility
- Hosting for a group of networked servers
- Own power, cooling & networking infrastructure.
Azure Regions
Key characteristics
- Geographical area on the planet
- One or usually more data centers connected with a low-latency network(< 2 milliseconds)
- Location for your services
- Some Services are available only in certain regions
- Some services are global and, as such, are not assigned/deployed in a specific region
- Globally available with 50+ regions
- Special government regions(US DOD Central, US Gov Virginia, etc)
- Special partnered regions(China East, China North)
Availability Zones
Key Characteristics
- Regional feature
- Grouping of physically separate facilities
- Designed to protect from data center failures
- If the zone goes down, others continue working
- Zonal Services (Virtual Machines Disks, etc)
- Not all regions are supported
- The supported region has three or more zones
- A zone is one or more data centers
Region Pairs
Key Characteristics
- Each region is paired with another region, making it a region pair
- Region pairs are static and cannot be chosen
- Each pair resides within the same Geography
- The exception is Brazil’s South
- Physical isolation with at least 300 miles distance(when possible)
- Some Services have platform-provided replication
- Planned updates across the pairs
- Data residency is maintained for disaster recovery
| Region Pair A | Region Pair B |
| East US | West US |
| UK West | UK South |
| North Europe(Ireland) | West Europe(Netherlands) |
| East Asia(Hong Kong) | Southeast Asia(Singapore) |
Geographies
Key Characteristics
- Discrete market
- Typically contains two or more regions
- Ensures data residency, sovereignty, resiliency, and compliance requirements are met
- Fault-tolerant to protect from region-wide failures
- Broken up into areas
- Americas,
- Europe
- Asia Pacific
- Middle East and Africa
- Each region belongs only to one Geography
Azure Resource Structure
Resources
Key Characteristics
- Objects used to manage services in Azure
- Represents the service lifecycle
- Every resource is a JSON Template
- Saved as JSON Definition
Resource Groups
Key Characteristics
- Grouping of resources
- Holds logically related resources
- Organizing by –
- Type
- Lifecycle(app,environment)
- Department
- Billing, Location, or a combination of those
- Each resource must be and only one resource group
- Resource groups have their location assigned
- Resources in the resource groups can reside in different locations
- Resources can be moved between the resource groups
- Resource groups can’t be nested
- Organize based on your organization’s needs, but consider
- Billing
- Security and access management
- Application Lifecycle
Azure Resource Manager
Key Characteristics
- Management Layer for all resources and resource groups
- Unified language
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