Prometheus/Alertmanager inhibit rules - devops

Question

I have the following inhibit rule:
inhibit_rules:
- source_match:
severity: 'critical'
target_match:
severity: 'high'
equal: ['alertname]
and also two alerts accordingly with severity high and critical.
Alert 1
- alert: ContainerCpuUsage
expr: ContainerCpuUsage > 90
for: 30m
labels:
severity: high
topic: container
annotations:
summary: "Container CPU usage for pod '{{ $labels.pod }}' is above 90% for the last 30 minutes."
description: "Container CPU usage (name {{ $labels.pod }})\nMeasuredValue={{ printf \"%.2f\" $value }}%"
Alert 2
- alert: ContainerCpuUsage
expr: ContainerCpuUsage > 98
for: 30m
labels:
severity: critical
topic: container
annotations:
summary: "Container CPU usage for pod '{{ $labels.pod }}' is above 98% for the last 30 minutes."
description: "Container CPU usage (name {{ $labels.pod }})\nMeasuredValue={{ printf \"%.2f\" $value }}%"
The idea is when the CPU usage goes suddenly from 20%, let say, to 99% a critical alert should be fired and also a high alert should not be fired.With inhibit rules above it works perfectly.
But when the CPU usage goes suddenly from 20%, let say, to 91% a high alert is fired and this is correct.After some min if CPU usage goes further to 99% a second alert,a critical one is also fired.So i have in total 2 alerts open,high and critical.
What i want is that if CPU usage >98% high alert should be closed and only critical remains open.Why high alert is not closed/inhibit?
If an alert is already fired,can inhibit rules close it?

Answer 1

The "inhibit_rules" just mutes the alerts, in other words, it prevents sending new notifications (emails, messages, etc) to recipients about the alerts, but does not inactive them.