☁️ Microsoft Azure Fundamentals (AZ-900)
1️⃣ Cloud Concepts & Shared Responsibility Model
Definition: Cloud Computing internet ke through on-demand computing services (servers, storage, databases, networking, software) provide karne ka delivery model hai jisme Pay-As-You-Go pricing hoti hai.
| Cloud Service Category | Managed by Customer | Managed by Cloud Provider (Microsoft) | Real-World Example |
|---|---|---|---|
| IaaS (Infrastructure as a Service) | OS, Runtime, Middleware, Apps, Data | Physical Hardware, Virtualization, Data Center | Azure Virtual Machines |
| PaaS (Platform as a Service) | Application Code aur Data sirf | OS patches, Scaling, Hardware, Runtime | Azure App Services, Azure SQL |
| SaaS (Software as a Service) | User access & Configuration data | Entire software stack, infrastructure & updates | Microsoft 365, OneDrive |
CapEx vs OpEx:
• CapEx (Capital Expenditure): Physical on-premise servers khareedne me massive upfront investment lagti hai.
• OpEx (Operational Expenditure): Sirf utna hi pay karna jitne resources actual me use kiye ja rahe hain (Zero upfront server cost).
• CapEx (Capital Expenditure): Physical on-premise servers khareedne me massive upfront investment lagti hai.
• OpEx (Operational Expenditure): Sirf utna hi pay karna jitne resources actual me use kiye ja rahe hain (Zero upfront server cost).
2️⃣ Cloud Deployment Models
| Model | Ownership & Location | Primary Benefit |
|---|---|---|
| Public Cloud | Third-party provider (Azure) sabhi organizations ke liye shared infrastructure host karta hai. | High scalability, zero hardware maintenance, pay-as-you-go. |
| Private Cloud | Single organization ka dedicated private data center. | Strict regulatory compliance aur complete physical control. |
| Hybrid Cloud | Public cloud aur on-premise private data center ka encrypted connection. | Sensitive data on-premise rahega, bursting workload public cloud par chalega. |
3️⃣ Azure Global Infrastructure Deep Dive
Azure high availability ensure karne ke liye hierarchical physical infrastructure use karta hai:
- Geographies: Discrete markets (e.g. India, Europe, US) jo data residency aur compliance boundary preserve karte hain.
- Regions: Geographies ke andar specific locations (e.g. Central India - Pune, South India - Chennai) jahan latency-defined network se interconnected data centers hote hain.
- Availability Zones (AZs): Single region ke andar physically separate data centers jinke paas independent power, cooling aur networking hoti hai (Minimum 3 zones per supported region).
- Region Pairs: Har region kam se kam 300+ miles door kisi doosre paired region se link hota hai natural disaster recovery ke liye (e.g. Central India ↔ South India).
4️⃣ Core Compute Services (VMs vs Serverless)
| Compute Service | Type | Scaling Nature | Best Use-Case |
|---|---|---|---|
| Azure VM | IaaS | Manual or VM Scale Sets (VMSS) | Custom legacy software migrations requiring OS full control. |
| Azure App Service | PaaS | Automated horizontal/vertical scaling | Web applications (Node.js, Python, .NET) deploy karna bina OS manage kiye. |
| Azure Functions | Serverless (FaaS) | Event-driven instant micro-billing | Image resizing on upload, IoT background telemetry processing. |
| Azure Kubernetes Service (AKS) | Managed K8s | Cluster auto-scaler | Enterprise microservices orchestration. |
Live Azure Availability SLA & Redundancy Simulator
[Azure Resource Manager]: Ready. Select an infrastructure architecture to calculate uptime SLA and fault tolerance...
5️⃣ Storage Services & Redundancy Options
1. Azure Storage Types
- Blob Storage: Unstructured data store (images, videos, backups, logs).
- Azure Files: SMB/NFS protocol par based cloud network file shares.
- Azure Disks: Virtual machines ke liye block-level persistent storage.
2. Data Redundancy Strategies
| Strategy | Replication Scope | Durability Target |
|---|---|---|
| LRS (Locally Redundant Storage) | Single data center ke andar 3 copies replicate hoti hain. | 99.999999999% (11 nines) |
| ZRS (Zone-Redundant Storage) | Same region ke 3 alag-alag Availability Zones me replicate hoti hain. | 99.9999999999% (12 nines) |
| GRS (Geo-Redundant Storage) | Primary region (LRS) + Secondary Paired Region (LRS) me 6 copies. | 99.99999999999999% (16 nines) |
6️⃣ Azure Virtual Networks (VNet) & Security
Azure me isolated private network space banana:
# Basic Azure CLI command to provision resource group and VNet
az group create --name RG-Production --location centralindia
az network vnet create \
--name VNet-Prod \
--resource-group RG-Production \
--address-prefix 10.0.0.0/16 \
--subnet-name Subnet-Web \
--subnet-prefix 10.0.1.0/24
Network Security Group (NSG): Virtual firewall jo subnet ya NIC level par inbound aur outbound IP traffic ko allow ya deny karta hai (5-tuple rules: Source, Source Port, Destination, Destination Port, Protocol).
7️⃣ Identity, Governance & Security
1. Microsoft Entra ID (Formerly Azure AD)
Cloud-based Identity & Access Management (IAM) service jo single sign-on (SSO), Multi-Factor Authentication (MFA) aur Conditional Access provide karti hai.
2. Role-Based Access Control (RBAC)
Built-in primary roles: Owner (Full access + manage permissions), Contributor (Manage resources, cannot delegate permissions), Reader (View only).
3. Azure Policy vs Resource Locks
- Azure Policy: Guardrails enforce karta hai (e.g. "Only Central India region allow karo", "Require tags on resources").
- Resource Locks: Accidental deletion prevent karne ke liye:
CanNotDeleteaurReadOnly.
