Maintenance And Monitoring » Week 2 » Reliable Google Cloud Infrastructure: Design And Process

Q: Your service has an availability SLO of 99%. What could you use to monitor whether you are meeting it?

This answer is correct. Availability is the percentage of time a system is running and able to process requests. Monitoring this metric will enable the derivation of the SLO metric.

Q: You're deploying test environments using Compute Engine VMs. Some downtime is acceptable, and it is very important to deploy them as inexpensively as possible. What single thing below could save you the most money?

This answer is correct. These are the most cost-effective solution as required in the question(up to 80% lower than equivalent non-preemptible machines) and the fact that some downtime is acceptable means that the requirement can be met with preemptible machines.

Q: You made a minor update to a service and would like to test it in production by sending a small portion of requests to the new version. Which would you choose?

This answer is correct. Canary deployment aims to eliminate/reduce risks by applying the update to a small subset of users to test out a new feature and best fits the requirements of the question.

Q: You've made a minor fix to one of your services. You want to deploy the new version with no downtime. Which would you choose?

This answer is correct. A rolling update will update instances incrementally until all have been updated. This strategy can be controlled, for example, by using a managed instance group with Compute Engine or with GKE.