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.

Practice

1. What is the main purpose of an alerting policy in Google Cloud Monitoring?

easy

A. To watch cloud metrics and notify when something needs attention

B. To deploy virtual machines automatically

C. To store data backups securely

D. To manage user access permissions

Solution

1. Step 1: Understand the role of alerting policies

   An alerting policy monitors cloud metrics continuously to detect issues.

2. Step 2: Identify the main function

   When a condition is met, it sends notifications to inform the team.

3. Final Answer:

   To watch cloud metrics and notify when something needs attention -> Option A

4. Quick Check:

   Alerting policy = notify on metric issues [OK]

Hint: Alerting policies notify on metric changes [OK]

Common Mistakes:

• Confusing alerting with deployment
• Thinking alerting manages backups
• Mixing alerting with access control

2. Which of the following is the correct way to specify a notification channel in a Google Cloud alerting policy configuration?

easy

A. "channels": "my-project/notification/12345"

B. "notifyChannel": "12345"

C. "notification": "channel-12345"

D. "notificationChannels": ["projects/my-project/notificationChannels/12345"]

Solution

1. Step 1: Recall notification channel format

   Google Cloud expects notification channels as full resource names in an array.

2. Step 2: Match correct syntax

   "notificationChannels": ["projects/my-project/notificationChannels/12345"] uses the correct JSON key and full resource path format.

3. Final Answer:

   "notificationChannels": ["projects/my-project/notificationChannels/12345"] -> Option D

4. Quick Check:

   Notification channels use full resource names in array [OK]

Hint: Use full resource names in an array for notificationChannels [OK]

Common Mistakes:

• Using wrong key names like notifyChannel
• Providing notification channel as a string, not array
• Omitting project prefix in resource name

3. Given this alerting policy condition snippet:

{"conditionThreshold": {"filter": "metric.type=\"compute.googleapis.com/instance/cpu/utilization\"", "comparison": "COMPARISON_GT", "thresholdValue": 0.8, "duration": "300s"}}

What triggers this alert?

medium

A. CPU utilization is less than 80% for 5 minutes

B. CPU utilization is greater than 80% for 5 minutes

C. CPU utilization is exactly 80% at any time

D. CPU utilization is greater than 80% for 30 seconds

Solution

1. Step 1: Interpret the condition filter and comparison

   The filter targets CPU utilization metric, and comparison is greater than 0.8 (80%).

2. Step 2: Understand the duration

   The duration is 300 seconds, meaning the condition must hold for 5 minutes continuously.

3. Final Answer:

   CPU utilization is greater than 80% for 5 minutes -> Option B

4. Quick Check:

   Threshold > 0.8 for 300s = alert [OK]

Hint: Check comparison and duration for alert trigger [OK]

Common Mistakes:

• Confusing greater than with less than
• Ignoring duration requirement
• Assuming exact equality triggers alert

4. You created an alerting policy but no notifications are sent when the condition is met. What is the most likely cause?

medium

A. Notification channels are not configured or linked properly

B. The metric filter is too broad

C. The alerting policy is disabled by default

D. The project has no billing account

Solution

1. Step 1: Check notification channel setup

   If no notifications arrive, the most common cause is missing or incorrect notification channels.

2. Step 2: Verify alerting policy status and billing

   Alerting policies are enabled by default and billing issues usually don't block notifications.

3. Final Answer:

   Notification channels are not configured or linked properly -> Option A

4. Quick Check:

   No notifications usually mean missing channels [OK]

Hint: Verify notification channels linked to policy [OK]

Common Mistakes:

• Assuming alerting policies are disabled by default
• Blaming billing for notification failure
• Ignoring notification channel configuration

5. You want to create an alerting policy that notifies your team only if CPU usage is above 70% for 10 minutes, but only during business hours (9 AM to 5 PM). Which approach best achieves this?

hard

A. Set the alert threshold to 70% and rely on team to ignore alerts outside business hours

B. Create an alerting policy without conditions and manually check CPU usage during business hours

C. Use an alerting policy with a condition on CPU usage and add a time window using an uptime check or schedule-based notification channel

D. Configure the alerting policy to notify continuously regardless of time

Solution

1. Step 1: Define CPU usage condition with duration

   Set condition threshold to >70% CPU usage sustained for 10 minutes.

2. Step 2: Limit notifications to business hours

   Use scheduling features like uptime checks or notification channel schedules to restrict alerts to 9 AM-5 PM.

3. Final Answer:

   Use an alerting policy with a condition on CPU usage and add a time window using an uptime check or schedule-based notification channel -> Option C

4. Quick Check:

   Combine metric condition + time window for precise alerts [OK]

Hint: Combine metric condition with time-based notification [OK]

Common Mistakes:

• Ignoring time restrictions in alerting policy
• Relying on manual checks instead of automation
• Not setting duration for CPU usage condition