Alerting policies in GCP - Step-by-Step Execution

Process Flow - Alerting policies

Start

↓

Define Metric & Condition

↓

Set Threshold & Duration

↓

Configure Notification Channels

↓

Activate Policy

↓

Monitor Metric

↓

Condition Met?

No→Continue Monitoring

Yes↓

Send Alert Notification

↓

User Responds

↓

End

This flow shows how an alerting policy is created, activated, and triggers notifications when conditions are met.

Execution Sample

GCP

Create alert policy:
- Metric: CPU usage
- Condition: > 80% for 5 min
- Notify: Email
Activate policy
Monitor CPU
If CPU > 80% for 5 min, send email alert

This example sets an alert for CPU usage above 80% sustained for 5 minutes, sending an email notification.

Process Table

Step	Action	Metric Value	Condition Check	Notification Sent
1	Policy created with CPU > 80% for 5 min	-	-	No
2	Policy activated	-	-	No
3	CPU usage monitored: 75%	75%	75% > 80%? No	No
4	CPU usage monitored: 82%	82%	82% > 80%? Yes, duration < 5 min	No
5	CPU usage monitored: 85% (5 min elapsed)	85%	85% > 80%? Yes, duration >= 5 min	Yes, email sent
6	User receives alert and responds	-	-	Yes
7	CPU usage monitored: 70%	70%	70% > 80%? No	No

💡 Monitoring continues until condition is met; alert sent when CPU > 80% for 5 minutes.

Status Tracker

Variable	Start	After Step 3	After Step 4	After Step 5	After Step 7
CPU Usage (%)	-	75	82	85	70
Condition Met Duration (min)	0	0	less than 5	5	0
Alert Sent	No	No	No	Yes	No

Key Moments - 2 Insights

Why is no alert sent immediately when CPU usage first goes above 80%?

Because the condition requires CPU usage to be above 80% continuously for 5 minutes (see steps 4 and 5 in execution_table). The alert triggers only after this duration.

What happens if CPU usage drops below 80% before 5 minutes?

The duration counter resets, so the condition is not met and no alert is sent (refer to step 7 where CPU drops to 70%).

Visual Quiz - 3 Questions

Look at the execution_table, at which step is the alert notification sent?

A Step 4

B Step 5

C Step 3

D Step 7

💡 Hint

Check the 'Notification Sent' column in execution_table rows.

According to variable_tracker, what is the CPU usage after step 4?

A 82%

B 75%

C 85%

D 70%

💡 Hint

Look at the 'CPU Usage (%)' row under 'After Step 4' column.

If the threshold was changed to 90%, how would the alert timing change?

A Alert would trigger earlier

B Alert timing stays the same

C Alert would never trigger in this example

D Alert triggers immediately

💡 Hint

Refer to execution_table CPU values and threshold condition.

Concept Snapshot

Alerting policies monitor metrics and trigger notifications.
Define metric, condition, threshold, and duration.
Configure notification channels (email, SMS, etc.).
Activate policy to start monitoring.
Alert triggers only if condition holds for set duration.
User receives notification to respond.

Full Transcript

An alerting policy in cloud monitoring watches a metric like CPU usage. You set a condition, for example, CPU usage above 80% for 5 minutes. You also set who to notify, such as an email address. When the policy is active, the system checks the metric regularly. If the CPU usage goes above 80% but not for 5 minutes yet, no alert is sent. Once the CPU stays above 80% for 5 minutes, the alert notification is sent. If the CPU drops below 80% before 5 minutes, the timer resets and no alert is sent. This helps avoid false alarms from short spikes. The user then receives the alert and can take action.