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Serverless vs PaaS vs IaaS decision in Azure - Quick Revision & Key Differences

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Recall & Review
beginner
What is Serverless computing in Azure?
Serverless computing means you write code and Azure runs it without you managing servers. You pay only for the time your code runs. Azure handles scaling automatically.
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beginner
Define PaaS (Platform as a Service) in Azure.
PaaS provides a ready environment to build and run apps. Azure manages servers, storage, and networking. You focus on your app code and data.
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beginner
What does IaaS (Infrastructure as a Service) offer in Azure?
IaaS gives you virtual machines and storage in Azure. You manage the OS, apps, and data. Azure manages the physical hardware.
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intermediate
When to choose Serverless over PaaS or IaaS?
Choose Serverless if you want to run small pieces of code on demand, with automatic scaling and no server management. Good for event-driven apps and unpredictable workloads.
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intermediate
What factors influence choosing between Serverless, PaaS, and IaaS?
Consider control level, management effort, scalability needs, cost model, and app complexity. Serverless is least management, IaaS most control, PaaS in between.
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Which Azure service model requires you to manage the operating system?
AServerless
BPaaS
CIaaS
DSaaS
Which model automatically scales your code without server management?
AServerless
BPaaS
COn-premises
DIaaS
If you want to focus only on app code and not infrastructure, which Azure model fits best?
AIaaS
BBare metal
CServerless
DPaaS
Which model is best for unpredictable workloads with event-driven triggers?
APaaS
BServerless
CIaaS
DDedicated servers
Which model gives you the most control over the environment?
AIaaS
BPaaS
CServerless
DSaaS
Explain the main differences between Serverless, PaaS, and IaaS in Azure.
Think about who manages what and how much control you have.
You got /3 concepts.
    Describe scenarios when you would choose Serverless, PaaS, or IaaS.
    Consider workload type and management preferences.
    You got /3 concepts.

      Practice

      (1/5)
      1. Which Azure service model lets you run your code without worrying about managing servers and charges you only when your code runs?
      easy
      A. Serverless
      B. PaaS
      C. IaaS
      D. On-premises servers

      Solution

      1. Step 1: Understand Serverless model

        Serverless runs your code without managing servers and charges based on usage.

      2. Step 2: Compare with PaaS and IaaS

        PaaS provides a platform but you still deploy apps; IaaS requires managing virtual machines.

      3. Final Answer:

        Serverless -> Option A

      4. Quick Check:

        Serverless = code runs without server management [OK]
      Hint: Serverless = no server management, pay per execution [OK]
      Common Mistakes:
      • Confusing PaaS with Serverless
      • Thinking IaaS is serverless
      • Assuming on-premises is cloud
      2. Which Azure service model requires you to manage virtual machines and network settings yourself?
      easy
      A. Serverless
      B. SaaS
      C. PaaS
      D. IaaS

      Solution

      1. Step 1: Identify IaaS responsibilities

        IaaS gives full control over virtual machines and network settings, so you manage them.

      2. Step 2: Contrast with other models

        Serverless and PaaS abstract server management; SaaS is software delivered fully managed.

      3. Final Answer:

        IaaS -> Option D

      4. Quick Check:

        IaaS = manage VMs and network [OK]
      Hint: IaaS means managing your own virtual machines [OK]
      Common Mistakes:
      • Mixing PaaS with IaaS management level
      • Thinking Serverless requires VM management
      • Confusing SaaS with IaaS
      3. You want to deploy a web app quickly without managing servers but need some control over the environment. Which Azure model fits best?
      medium
      A. Serverless
      B. PaaS
      C. IaaS
      D. On-premises

      Solution

      1. Step 1: Analyze deployment needs

        Quick deployment without server management suggests Serverless or PaaS.

      2. Step 2: Consider control over environment

        Serverless offers less control; PaaS provides a ready platform with some environment control.

      3. Final Answer:

        PaaS -> Option B

      4. Quick Check:

        PaaS = quick deploy + some control [OK]
      Hint: PaaS balances ease and control for app deployment [OK]
      Common Mistakes:
      • Choosing Serverless when environment control is needed
      • Picking IaaS for quick deployment
      • Confusing on-premises with cloud models
      4. A developer deployed an app on Azure IaaS but forgot to configure the network security group. What is the likely issue?
      medium
      A. App is exposed to the internet without protection
      B. App will not run because code is missing
      C. Azure automatically secures the app by default
      D. App will run serverless without VMs

      Solution

      1. Step 1: Understand IaaS network responsibility

        In IaaS, you must configure network security groups to protect VMs and apps.

      2. Step 2: Consequence of missing security group

        Without it, the app is exposed to the internet without firewall protection.

      3. Final Answer:

        App is exposed to the internet without protection -> Option A

      4. Quick Check:

        IaaS needs manual network security setup [OK]
      Hint: IaaS needs manual network security setup [OK]
      Common Mistakes:
      • Assuming Azure auto-secures IaaS apps
      • Thinking app won't run without code
      • Confusing serverless with IaaS
      5. Your company needs to run a batch job that runs only a few minutes every day, with minimal management and cost. Which Azure model should you choose?
      hard
      A. IaaS with dedicated VMs running 24/7
      B. PaaS with always-on app service
      C. Serverless functions triggered by schedule
      D. On-premises servers scheduled manually

      Solution

      1. Step 1: Analyze job characteristics

        The batch job runs briefly daily, so paying for always-on resources wastes money.

      2. Step 2: Match model to cost and management needs

        Serverless functions run only when triggered, minimizing cost and management.

      3. Step 3: Eliminate other options

        IaaS and PaaS keep resources running continuously, increasing cost; on-premises adds manual overhead.

      4. Final Answer:

        Serverless functions triggered by schedule -> Option C

      5. Quick Check:

        Short, infrequent jobs = Serverless [OK]
      Hint: Use serverless for short, infrequent tasks to save cost [OK]
      Common Mistakes:
      • Choosing always-on VMs for short jobs
      • Picking PaaS without considering cost
      • Ignoring serverless scheduling options