🧠 Compute Demystified: Powering the Cloud, One VM at a Time

Hey there, cloud cadet!
I'm currently preparing for the AZ-900: Microsoft Azure Fundamentals exam, and as part of my learning journey, I’ve decided to share my notes with you in a simple, no-fluff format.

Today, we’re diving into one of the core building blocks of the cloud: Compute services.

✅ Core Azure Compute Services

💻 Azure Virtual Machines (VMs) – IaaS

• You manage: OS, apps, patches, security.

• Great for legacy apps, custom software, or lift-and-shift scenarios.

• Pricing based on VM size, OS, storage, and region.

• Supports availability sets, zones, and scale sets.

VM Series (What to Remember):

• B-series: Burstable workloads.

• D-series: General purpose (web servers, databases).

• E-series: Memory optimized (SQL, cache).

• F-series: Compute optimized (CPU-heavy).

• Lsv2-series: Storage optimized (high IOPS).

• N-series: GPU (AI, ML, rendering).

• M-series: High memory (SAP).

🌐 Azure App Service – PaaS

• Host web apps and APIs.

• Supports .NET, Node.js, Java, Python, PHP, and more.

• App Service Plan determines:

  • Region

  • Pricing tier

  • Scaling (manual/auto)

• Multiple apps can share the same App Service Plan.

App Service Plan Tiers:

• Free/Shared – Dev/test only

• Basic – Manual scale

• Standard – Auto-scale + staging

• Premium – Faster & more scalable

• Isolated – Secure, in VNet

📦 Azure Container Instances (ACI)

• Run containers without managing servers.

• No orchestration (single container or simple groups).

• Best for quick tasks, jobs, or APIs.

• Pay per second of CPU/memory used.

🚢 Azure Kubernetes Service (AKS)

• Managed Kubernetes to run containerized microservices.

• Azure manages the master nodes.

• Supports auto-scaling, updates, and RBAC.

• Best for complex, production-grade container workloads.

⚡ Azure Functions – Serverless

• Event-driven code execution (e.g. timers, HTTP triggers).

• Scales automatically based on events.

• Billing: Pay only for executions and runtime.

Max Execution Time:

• Consumption plan: 5 minutes (extendable to 10)

• Premium/Dedicated: Unlimited

🧑‍💻 Azure Virtual Desktop (AVD)

• Host Windows desktops in the cloud.

• Accessible from anywhere.

• Integrates with Microsoft 365 and Azure AD.

• Useful for secure remote access or centralized desktops.

🧮 Azure Batch

• Run large-scale batch or parallel jobs.

• Automatically provisions and manages compute.

• Ideal for rendering, modeling, simulations.

• Works with custom scripts, containers, and apps.

🛡️ High Availability & SLAs

📊 Scaling Options

💰 Compute Pricing Models

• VMs: Per second; price varies by region and specs.

• App Service: Based on App Service Plan.

• ACI / Functions: Per execution (true pay-per-use).

• AVD: Per user and VM usage.

• AKS: Pay for agent nodes (control plane is free).

• Batch: Depends on the VM resources used.

🔐 Security & Identity

• Use Azure AD + RBAC to control access to compute resources.

• Apply NSGs (Network Security Groups) to protect VMs.

• App Service and Functions support managed identities.

🌍 Hybrid & Management Tools

• Azure Arc: Manage on-prem VMs & Kubernetes like Azure resources.

• Management Tools:

  • Azure Portal (GUI)

  • Azure CLI / PowerShell

  • ARM Templates or Bicep (Infrastructure as Code)

📌 Exam Tips (AZ-900 Specific)

• Know the difference between IaaS, PaaS, Serverless.

• Expect scenario-based questions: “Which service should you choose if…”

• Memorize SLA levels and scaling capabilities.

• Understand when to use each compute service and its pricing implications.