Create an Alert System

In this step, we will create an alert system using CloudWatch Alarm, a service that helps us detect and notify when metrics exceed thresholds.

1. Go to the CloudWatch Console

• Under the Alarms section, click on In alarm
• Then click Create alarm

2. In Step 1, click Select metric

3. In the Select metric interface:

• Choose Browse
• Click on the previously created service
• Then click Select metric

4. After selection, your chosen metric will appear along with related details

5. Configure the metric settings as shown:

6. Scroll down a bit:

• For Threshold type, select Static
• Under Whenever ProcessingTime is…, choose Greater
• Set the value to 350
• For Datapoints to alarm, set both min and max to 3

7. Scroll to the bottom and click Next

8. In Step 2 interface:

• Under Alarm state trigger, select In alarm
• Under Send a notification to the following SNS topic, choose Create new topic
• Name the new topic
• Enter your email under Email endpoints that will receive the notification (make sure to confirm when AWS sends the verification email)
• Click Create topic

9. Scroll down and click Next

10. In Step 3:

• Set Alarm name to HighProcessingLatency
• In Description, enter: Alert when Lambda ProcessingTime > 350ms avg in 1 min
• Click Next

11. The Overview screen will appear. Review your settings and click Create alarm

12. You will be redirected to the Alarms Management screen — click on the alarm you just created

13. Review the alarm details and important configuration metrics

14. Use Postman to send a high volume of test requests

15. Go back to the Alarms page and check the alarm status and metrics

16. Wait for an alert email from AWS

And that’s it — we’ve successfully created an alert system. In the next section, we’ll explore cost analysis and system optimization.