A cloud administrator is tasked with reducing costs for a development environment that runs 24/7. The environment consists of several virtual machines and a load balancer. Which action would most effectively reduce costs without affecting developer access during business hours?
Correct. Shutting down VMs eliminates compute costs during idle periods, directly reducing expenses.
Why this answer
Scheduling VMs to shut down during nights and weekends directly reduces compute costs by eliminating runtime charges when the development environment is not needed. This approach preserves full availability during business hours without requiring architectural changes, and it is the most straightforward way to cut costs for a 24/7-running environment that only needs daytime access.
Exam trap
The trap here is that candidates often choose auto-scaling or burstable instances because they focus on reducing per-unit cost rather than eliminating runtime, missing the fact that shutting down VMs entirely during off-hours yields the greatest savings for a development environment with predictable idle periods.
How to eliminate wrong answers
Option A is wrong because auto-scaling to run only one instance during off-hours still keeps that instance running and incurring costs, and it does not address the load balancer's cost; moreover, auto-scaling is designed for variable demand, not for eliminating runtime entirely. Option C is wrong because reserved instances require a 1- or 3-year commitment and are intended for steady-state workloads, not for a development environment that can be shut down; they would lock in costs rather than reduce them for intermittent usage. Option D is wrong because changing to burstable instance types (e.g., AWS T-series) reduces per-hour cost but still charges for every hour the VMs run, so it does not eliminate the cost of running 24/7; it only lowers the rate, not the runtime.