Amazon CloudWatch Composite Alarms adds threshold-based alerting

Amazon CloudWatch now enables you to create more flexible alerting policies by triggering notifications when a specific subset of your monitored resources need attention. Using CloudWatch composite alarms, you can create a rule to take action only when a certain combination of alarms is activated. This enhancement lets you choose to receive alerts only when a certain number of resources are impacted, helping you focus on meaningful incidents.

The new threshold function in composite alarms allows you to eliminate unnecessary alerts for minor issues while ensuring quick notification of significant problems. IT operations teams can configure alerts to trigger when, for instance, at least two out of four storage volumes are running low on capacity, or when 50% of hosts in a cluster show high CPU utilization. The feature supports both fixed numbers and percentages, making it easy to maintain effective monitoring even as your infrastructure grows or changes.

This capability is now available in all commercial AWS regions, the AWS GovCloud (US) Regions, and the China Regions.

To create a threshold-based condition in a composite alarm, simply use the AT_LEAST function in the alarm’s condition. Composite alarms’ pricing applies, see CloudWatch pricing for details. To learn more about the threshold function’s parameters, visit the Amazon CloudWatch documentation for composite alarms.