Why did my CloudWatch alarm send me a notification after a single breached data point?

Short description

Your CloudWatch alarm might be configured to treat a missing data point the same way as a breaching data point.

Your alarm might go into the ALARM state if the following are met: 

• All data points are missing except one breaching data point. This causes an ALARM state even if the total number of breaching data points is lower than the Datapoints to Alarm setting.
• The oldest available breaching data point in the alarm's evaluation range is as old as the value of Datapoints to Alarm.
• Missing data is treated as missing.

Resolution

To configure your alarm to not send notifications when a single data point is breached, you can edit your alarm.

Take one of the following actions:

• Change how missing data points are evaluated to NOT BREACHING.
• Use a longer period for a data point.
• Increase the number of evaluation periods before the alarm is activated.

Related information

describe-alarm-history

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