Create alarms on log anomaly detectors - Amazon CloudWatch Logs
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Create alarms on log anomaly detectors

You can create an alarm for a log anomaly detector in a log group. You can specify for the alarm to go into ALARM state when a specified number of anomalies are found in the log group during a specified period of time. You can also use filters so that only anomalies of specified priorities are counted by the alarm.

To create an alarm for a log anomaly detector
  1. Open the CloudWatch console at

  2. In the navigation pane, choose Logs, Log Anomalies.

    The table of log anomaly detectors appears.

  3. Choose the radio button for the anomaly detector that you want to set the alarm for, and choose Create alarm.

    The CloudWatch alarm creation wizard appears. The LogAnomalyDetector field displays the name of the anomaly detector that you chose. The Metric name field displays AnomalyCount.

  4. (Optional) To filter this alarm for anomaly priority, do one of the following:

    • To have the alarm count only high-priority anomalies, enter HIGH for LogAnomalyPriority.

    • To have the alarm count only high- and medium-priority anomalies, enter MEDIUM for LogAnomalyPriority.

    For more information about priority levels, see Severity and priority of anomalies and patterns.

  5. Choose to use a static or metric anomaly detection threshold for the alarm. This selection determines how the alarm threshold is set. A Static threshold means that the alarm threshold is a static, constant number that you choose. An Anomaly detection threshold means that CloudWatch determines a range of usual values, and the alarm triggers if the actual count crosses the threshold of this band. You don't have to choose Anomaly detection for a log anomaly detection alarm. For more information about metric anomaly detection, see Using CloudWatch anomaly detection.

  6. For Whenever your-metric-name is . . ., choose Greater, Greater/Equal, Lower/Equal, or Lower. Then for than . . ., specify a number for your threshold value. The alarm goes into ALARM state if the anomaly detector finds more than this number of alarms during a time specified by Period.

  7. Choose Additional configuration. For Datapoints to alarm, specify how many evaluation periods (data points) must be in the ALARM state to trigger the alarm. If the two values here match, you create an alarm that goes to ALARM state if that many consecutive periods are breaching.

    To create an M out of N alarm, specify a number for the first value that is lower than the number for the second value. For more information, see Evaluating an alarm.

  8. For Missing data treatment, choose how the alarm behaves when some data points are missing. For more information, see Configuring how CloudWatch alarms treat missing data.

  9. Choose Next.

  10. For Notification, choose Add notification, and then specify an Amazon SNS topic to notify when your alarm transitions to the ALARM, OK, or INSUFFICIENT_DATA state.

    1. (Optional) To send multiple notifications for the same alarm state or for different alarm states, choose Add notification.


      We recommend that you set the alarm to take actions when it goes into Insufficient data state in addition to when it goes into Alarm state. This is because many issues with the Lambda function that connects to the data source can cause the alarm to transition to Insufficient data.

    2. (Optional) To not send Amazon SNS notifications, choose Remove.

  11. (Optional) If you want your alarm to perform actions for Amazon EC2 Auto Scaling, Amazon EC2, tickets, or Amazon Systems Manager, choose the appropriate button, and specify the alarm state and action.


    Your alarm can perform Systems Manager actions only when it's in the ALARM state. For information about Systems Manager actions, see Configuring CloudWatch to create OpsItems and Incident creation.

  12. Choose Next.

  13. Under Name and description, enter a name and description for your alarm, and choose Next. The name must contain only UTF-8 characters, and can't contain ASCII control characters. The description can include markdown formatting, which is displayed only in the alarm Details tab in the CloudWatch console. The markdown can be useful to add links to runbooks or other internal resources.


    The alarm name must contain only UTF-8 characters. It can't contain ASCII control characters.

  14. Under Preview and create, confirm that your alarm's information and conditions are correct, and choose Create alarm.