PCA (Prometheus Certified Associate) sample exam question with answer 104

Question:
As a best practice, which of the following is a poor use of Alertmanager silencing?

1. Silence alerts from a server for brief period while it is being initialized
2. Silence alerts from a server that is being deprovisioned
3. Silence alerts from a set of servers which are undergoing routine maintenance
4. Silence a specific alert for which notifications are no longer desired

Answer:
D - is the correct answer. If a particular alert is no longer desired on a permanent basis, the alerting rule should be adjusted or removed.
A - this is a good use of Alertmanager silencing. Servers often can take a bit of time to fully initialize and run their exporters. If Prometheus discovers and scrapes the server during this time it could generate a false positive alert. Silencing can be a good way to prevent noise caused by this type of activity.
B - this is a good use of Alertmanager silencing. Many times Prometheus service discovery configurations will ensure that deprovisioned targets get dropped from monitoring and thus are not alerted on. Sometimes however, the alerting rule will evaluate before the target has been dropped and thus generate an unneeded alert. Silencing can help prevent this scenario.
C - this is an ideal use of Alertmanager silencing