Posted On: Mar 3, 2020

With Amazon CloudWatch composite alarms, you can now combine multiple alarms to reduce alarm noise and focus on critical operational issues. You can easily combine multiple alarms together into alarm hierarchies that only trigger once when multiple alarms fire at the same time. This helps you stay focused on finding the root cause of operational issues to reduce system and application downtime. 

CloudWatch composite alarms can provide an overall state for a grouping of resources like an application, AWS Region, or Availability Zone. This helps you focus on a smaller number of alarm signals which aggregate impact from all parts of your system or application. If an application issue affects several resources in the application, you will receive a single alarm notification for the entire application instead of one for each affected service component or resource. For example, say you deploy various devices into the homes of your customers. If a software deployment causes issues with a specific device model, operators may end up spending more time managing alarms firing off multiple devices, rather than troubleshooting and fixing the underlying issue for that model. With composite alarms, you can configure a condition for each device model in minutes so that you get only one alarm, and your operators can quickly deal with the root cause.  

Composite alarms publish to Amazon Simple Notification Service (Amazon SNS) topics, enabling you to do things such as trigger auto-scaling based on the state of multiple alarms. For example, correctly identifying application issues sometimes requires that you have multiple alarms in place. Say you have a batch job running at night. It is normal and expected to see 100% CPU utilization since all spare capacity during off hours is being used. However, if at the same time IO utilization is at 80%, that may indicate an application problem. Composite alarms allow you to alarm on only the combination of both. 

CloudWatch composite alarms are now available in all standard AWS Regions. See the CloudWatch pricing page for pricing details. Learn more about how to create composite alarms using the CloudWatch console, CLI, SDK, and CloudFormation.