A public website runs on four identical virtual machines behind a load balancer. Traffic triples while a television advert airs and falls back an hour later. The team wants instances added and removed automatically against CPU, all built from one image, with nobody clicking. Which option is designed for that?
Microsoft Certified: Azure Fundamentals (AZ-900), objective architecture-and-services. Azure architecture and services medium
Machine-checked — no person has signed for it. This question was read against the source cited below by an automated pass, which found no contradiction. That is a weaker claim than it sounds: the same kind of process wrote the question, so it can confirm its own mistake.
Treat it as a good draft rather than as settled fact, and read the source below before you rely on it. It is not used in mock exams here — only questions a person has signed for are.
The options
Correct Virtual Machine Scale Sets
Correct. A scale set creates and removes identical virtual machines from a common configuration, driven by autoscale rules or a schedule, and load balances across them.
Not correct An availability set holding the four machines
Wrong. An availability set improves the availability of a fixed number of machines by spreading them across fault and update domains. Nothing in it creates or removes an instance in response to load.
Not correct Resizing to a larger virtual machine before each advert
Wrong. Scaling up requires a resize, usually with a restart, has a hard ceiling at the largest size, and leaves you paying peak prices around the clock unless somebody remembers to shrink it again.
Not correct Azure Virtual Desktop
Wrong service entirely. Virtual Desktop delivers desktops and applications to end users; it is not a way to scale a website's web tier.
Why
Scaling up (a bigger machine) and scaling out (more machines) solve different problems, and the cloud's economic advantage lives in scaling out and back in again. Scale sets are the virtual machine expression of that: one image, many identical instances, a rule that adds and removes them, and instances that can be spread across availability zones for good measure.
Where this comes from
- Cited
- Microsoft AZ-900 study guide skill area architecture-and-services.compute-and-networking
Practise this
Reading one question is not practice. The trainer will draw a set from objective architecture-and-services and space the ones you get wrong.
Practise Microsoft Certified: Azure Fundamentals (AZ-900)
More questions on this objective
- An image-resizing routine runs for about two seconds whenever a file lands in a storage container — perhaps two hundred times on a busy day, and not at all on a quiet one. The team wants to pay for the work done and maintain no servers. Which compute option fits? machine-checked
- A fifteen-year-old accounting application needs a kernel-level driver, a scheduled task that edits the registry, and a runtime version nobody supports any more. The business wants it running in Azure this quarter with as few code changes as possible. Where does it go? machine-checked
- A team runs nine small services, each with its own conflicting library versions. They want each one packaged with its dependencies, starting in seconds, several to a host, without a separate operating system per service. Which compute type are they describing? machine-checked
- Which TWO of these statements about Azure compute types are true? machine-checked
- Three virtual machines form a quorum-based cluster in a region that has no availability zones. You want them placed so that neither a single rack losing power nor a single batch of planned host maintenance can take all three at once. What do you configure? machine-checked
- You are creating your first Azure virtual machine and want to know what it genuinely requires alongside it. Which statement is correct? machine-checked