Exam Professional Cloud Architect topic 1 question 111 discussion

B is the answer. https://cloud.google.com/blog/products/it-ops/best-practices-for-optimizing-your-cloud-costs Schedule VMs to auto start and stop: The benefit of a platform like Compute Engine is that you only pay for the compute resources that you use. Production systems tend to run 24/7; however, VMs in development, test or personal environments tend to only be used during business hours, and turning them off can save you a lot of money! https://cloud.google.com/blog/products/storage-data-transfer/save-money-by-stopping-and-starting-compute-engine-instances-on-schedule Cloud Scheduler, GCP’s fully managed cron job scheduler, provides a straightforward solution for automatically stopping and starting VMs. By employing Cloud Scheduler with Cloud Pub/Sub to trigger Cloud Functions on schedule, you can stop and start groups of VMs identified with labels of your choice (created in Compute Engine). Here you can see an example schedule that stops all VMs labeled "dev" at 5pm and restarts them at 9am, while leaving VMs labeled "prod" untouched

Ans ) B , assuming VM doesn't need to be up after office hours .

Cloud scheduler considering the requisites.

By utilizing preemptible VMs for the acceptance and development environments, you can significantly reduce costs without compromising the availability and performance of your critical production environment.

Stop the dev and acceptance envs is super weird. Any critical problems or overtimes will be an issue with this approach. Simple auto scaling environment is a good solution IMHO

B is right answer

Agree with B

Answer D A: too complex and maybe small or zero saving if you can't find a valid smaller machine type B: Not valid. Question says that PRE environments are not critical after office hours. But it doesn't say no service at all C: Some risk is introduced if you have different architecture on PRE than PRO envs D: It's the only valid and realiable option. Simple and effective. It's my choice. In a real scenario I will first start with this and then review if the savings are enough before more complicated choices

MIG's with autoscaling will scale to Zero if not needed

B for sure

Also managed instance group reduces instances in case of low/no-traffic incurring lesser charges. Ideally, its a cleaner approach considering the ask is to optimize during "idle time". Incase people are working in different time zones, late shifts it doesnt make sense to trigger shutdown at a predefined times.

B is the answer. But today, you don't need complicated CRON + CF. Auto shutdown by cron expression it's a feature built in: https://cloud.google.com/compute/docs/instances/schedule-instance-start-stop

really wondering why not C...Not critical is not equivalent with not running at all....

"are only critical during office hours" does not mean it could be completely stopped. So may the option C correct?

In my opinion B is over-engineered: Why not just add an "instance schedule" for start/stop the Compute Engines? Why creating a scheduler and writing a Cloud Function...

https://cloud.google.com/compute/docs/instances/viewing-and-applying-idle-vm-recommendations B seems close to this Google provided service option, the extra step should be using idle VM recommendations to find and stop idle VM instances to reduce waste of resources

Since the price of preemptibles is 1/4 the price of a standard machine D costs far less than B since office hours are 1/3 of whole day. It costs less to keep them running 24h as preemptibles.