Introduction to Application Monitoring with AWS CloudWatch Alarms

AWS CloudWatch provides multiple tools to set up monitoring for the application setup in AWS infrastructure. CloudWatch is best known as a log service that divides logs into log groups and streams. It also allows querying structured logs using fields automatically discovered in them.

It further provides alarm capabilities that can be triggered using log events or AWS service metrics. These are the focus of this article that allows dev-ops to minimize mean time to repair (MTTR) providing a better user experience to end users.

In addition, it also provides advanced capabilities to create dashboards for logs and service metrics, carry on synthetic e-2-e tests and much more. They will be discussed in the coming articles. Stay tuned!

CloudWatch Alarm Triggers

CloudWatch alarms have integrations with a multitude of AWS services to provide monitoring capabilities over them. The following list provides the most common triggers for alarms from information from those services.

Metric Thresholds: This is the most common way to trigger alarms. You can set thresholds on metrics such as CPU utilization, disk space, network traffic, etc. When the metric breaches the threshold you’ve defined, CloudWatch triggers the alarm.

Logs Metric Filters: You can create metric filters on your CloudWatch Logs to extract data and create custom metrics. Alarms can then be triggered based on these custom metrics.

Anomaly Detection: CloudWatch Anomaly Detection analyzes the historical values of a metric to create a model for normal behaviour. An alarm is triggered when the current metric value deviates significantly from the expected behaviour.

Composite Alarms: These alarms combine multiple alarms using logical operators (AND, OR) to create a single alarm state based on the status of multiple alarms.

AWS Health Events: You can create alarms based on AWS Health events, which notify you of changes in the health of AWS resources.

AWS CloudTrail Events: CloudTrail logs events about API activity in your AWS account. You can create alarms based on specific CloudTrail events.

AWS Budgets: While not directly related to CloudWatch alarms, AWS Budgets can help you monitor your AWS usage and expenses. You can set up notifications when your actual usage or costs exceed your budgeted amount.

CloudWatch Alarm Responses

Cloudwatch alarms integrate with many services to provide fine-grain control over how to respond to a CloudWatch alarm. You can either automatically remediate issues or generate alerts for manual interventions.

For automatic remediation, you can integrate alarms with Lambda functions, Step functions, AWS System manager automation or auto-scaling groups.

To generate notifications, you have the option to deliver alarm notifications through an integration with AWS Simple Notification Service (SNS) or AWS Service Health Dashboard. With either of those integrations, you have a wide variety of options for the destination of those notifications such as email, SMS, or integrate with third-party incident management tools like PagerDuty or Slack.

Best practices

Define Alarm Thresholds Carefully: Define alarm thresholds based on your application’s performance and operational requirements. Avoid setting thresholds too high or too low, as this can lead to either missed alerts or unnecessary notifications.

Leverage Anomaly Detection: Utilize CloudWatch Anomaly Detection to automatically detect abnormal behaviour in your metrics. This can help identify issues that may not be captured by static threshold-based alarms and reduce false positives.

Set Up Hierarchical Alarms: Establish hierarchical alarm structures to prioritize alerts and responses based on severity levels. For example, configure critical alarms to trigger immediate responses, while less severe alarms may trigger notifications for further investigation.

Implement Playbooks and Runbooks: Develop standardized playbooks and runbooks outlining procedures for responding to specific types of alarms. Document step-by-step instructions, escalation paths, and contacts for different scenarios to ensure a consistent and efficient response.

Monitor and Review Alarms Regularly: Regularly review and update CloudWatch alarms based on changes in application behaviour, performance, or business requirements. Continuously monitor alarm metrics to ensure they remain effective in detecting and alerting about potential issues.

Test Alarms and Response Procedures: Regularly test CloudWatch alarms and response procedures through tabletop exercises, simulations, or automated testing frameworks. Validate that notifications are received promptly, and response actions are executed as expected.

Conclusion

AWS CloudWatch alarms provide a convenient way to notify developers or automatically remediate spontaneous issues in your system or AWS account. CloudWatch alarms have deep integrations with a lot of AWS services which allows it to be responsive to a wide variety of events from those services.

You should continuously iterate on your alarm configurations and response processes based on feedback, insights from incidents, and changes in your environment. Emphasizing a culture of continuous improvement will enhance the effectiveness of your monitoring and response capabilities over time.