Describe serverless

Describe cloud computing

📘Microsoft Certified: Azure Fundamentals (AZ-900)


Microsoft Certified: Azure Fundamentals (AZ-900)

Main Topic: Describe Cloud Computing

Sub Topic: Describe Serverless


1. What Is Serverless Computing?

Serverless computing is a cloud computing model where:

  • You do not manage servers
  • You do not manage operating systems
  • You do not manage infrastructure
  • You only focus on your code and application logic

Even though the name says “serverless”, servers still exist.
The difference is:

Microsoft Azure manages the servers, scaling, patching, and infrastructure for you.

You only upload your code, and Azure runs it automatically when needed.


2. Why Serverless Is Important in Cloud Computing

In traditional IT environments:

  • You must create virtual machines (VMs)
  • Install operating systems
  • Configure networking
  • Apply patches and updates
  • Monitor and scale servers manually

In serverless computing, Azure handles all of this automatically.

This means:

  • Less management work
  • Faster development
  • Automatic scaling
  • Pay only when your code runs

3. Key Characteristics of Serverless (Very Important for Exam)

For the AZ-900 exam, remember these core features:

1. No Infrastructure Management

You do not manage:

  • Virtual machines
  • Storage configuration
  • Network infrastructure
  • OS patching

Azure manages everything.


2. Event-Driven Execution

Serverless applications run when something happens (an event).

Examples of IT events:

  • A file is uploaded to Azure Storage
  • A user submits a web form
  • A message arrives in a queue
  • A timer triggers a scheduled task
  • An HTTP request is received

The code runs only when triggered.


3. Automatic Scaling

Azure automatically:

  • Increases resources when demand increases
  • Reduces resources when demand decreases
  • Scales down to zero when not in use

You do not configure scaling manually.


4. Consumption-Based Pricing

You pay:

  • Only when your code runs
  • Based on execution time and resources used

If your function does not run:

  • You pay nothing (in most cases)

This makes serverless cost-efficient for unpredictable workloads.


4. Azure Services That Use Serverless

For the AZ-900 exam, you must know these key Azure serverless services:


1️⃣ Azure Functions

What It Is:

A service that lets you run small pieces of code without managing infrastructure.

How It Works:

  • You upload code
  • The code runs when triggered
  • Azure automatically scales it

Common Triggers:

  • HTTP request
  • Timer schedule
  • Blob storage upload
  • Message in Azure Queue
  • Event Grid event

Example in IT:

  • Automatically process uploaded files
  • Send notifications when a database record is created
  • Resize images after upload
  • Run background jobs

Key Exam Point:

Azure Functions is the main serverless compute service in Azure.


2️⃣ Azure Logic Apps

What It Is:

A service to automate workflows and integrate systems without writing much code.

It is mostly:

  • Drag-and-drop workflow creation
  • Prebuilt connectors

Used For:

  • Automating business processes
  • Connecting different systems (like SharePoint, Outlook, SQL, etc.)
  • Triggering workflows when events occur

Example in IT:

  • When a file is uploaded → Send email → Update database
  • When a ticket is created → Notify support team

Key Difference:

  • Azure Functions = Write code
  • Logic Apps = Build workflows visually

3️⃣ Azure Event Grid (Serverless Event Routing)

Azure Event Grid:

  • Sends events from one service to another
  • Works well with Azure Functions
  • Enables event-driven architecture

It helps build loosely coupled systems.


5. Serverless vs Traditional Cloud Models

For AZ-900, understand the comparison.

Traditional Virtual Machines (IaaS)

You manage:

  • VM
  • OS
  • Runtime
  • Scaling
  • Patching

More control, more responsibility.


Platform as a Service (PaaS)

You manage:

  • Application code

Azure manages:

  • Infrastructure
  • OS
  • Runtime

Example: Azure App Service


Serverless

You manage:

  • Only the function code or workflow

Azure manages:

  • Infrastructure
  • Scaling
  • Runtime
  • Availability
  • Maintenance

Serverless is even more abstracted than PaaS.


6. Benefits of Serverless (Important for Exam)

1. Cost Efficiency

  • Pay per execution
  • No idle server costs
  • Good for unpredictable workloads

2. Automatic Scaling

  • No need to configure scaling rules
  • Handles traffic spikes automatically

3. Faster Development

  • Developers focus only on code
  • No infrastructure setup
  • Rapid deployment

4. High Availability

  • Built-in fault tolerance
  • Managed by Azure

7. Limitations of Serverless

You should also understand limitations:

1. Cold Start

If a function has not run for some time:

  • It may take slightly longer to start

2. Execution Time Limits

Functions may have maximum execution duration (depending on plan).


3. Less Infrastructure Control

You cannot:

  • Customize server-level settings
  • Access underlying OS

8. When to Use Serverless (IT-Based Examples)

Serverless works best when:

  • Applications are event-driven
  • Workloads are unpredictable
  • Tasks run occasionally
  • You need quick automation

Common IT use cases:

  • Data processing pipelines
  • Scheduled background jobs
  • API backends
  • Real-time notifications
  • Integration between cloud services

9. Serverless Pricing Model (AZ-900 Key Concept)

Azure Functions (Consumption Plan):

You are charged based on:

  • Number of executions
  • Execution time
  • Memory used

This is called:

Consumption-based pricing

Important:
If your function does not run, you generally do not pay.


10. Key Exam Points to Remember

For the AZ-900 exam, remember:

✔ Serverless does NOT mean no servers exist
✔ Azure manages infrastructure automatically
✔ It is event-driven
✔ It scales automatically
✔ You pay only when code runs
✔ Azure Functions is the main serverless compute service
✔ Logic Apps is serverless workflow automation
✔ It is more abstract than IaaS and PaaS


11. Simple Definition for Non-IT Students

Serverless is a cloud model where:

  • You write small pieces of code.
  • Azure runs them automatically when needed.
  • You do not manage servers.
  • You pay only when the code runs.

It removes infrastructure complexity and lets you focus only on application logic.


Final Summary

Serverless computing in Azure:

  • Is event-driven
  • Requires no infrastructure management
  • Scales automatically
  • Uses consumption-based pricing
  • Is ideal for small, independent, triggered workloads

Main Azure services to remember:

  • Azure Functions
  • Azure Logic Apps
  • Azure Event Grid
Buy Me a Coffee