Fix CPU Usage Issues
On this page
System CPU alerts indicate that the CPU usage of the MongoDB
process has reached a specified threshold. This threshold is specified
when the alert is created.
Alert Conditions
You can configure the following alert conditions in the project-level alert settings page to trigger alerts.
System: CPU (Steal) % is occurs when the CPU usage exceeds the
guaranteed baseline CPU credit accumulation rate by the specified
threshold. For more information on CPU credit accumulation, refer to
the AWS documentation for Burstable Performance Instances.
Note
The System: CPU (Steal) % is alert is applicable when
the EC2 instance credit balance is exhausted. Atlas triggers
this alert only for AWS EC2 instances that support Burstable
Performance Instances.
Currently, these are M10 and M20 cluster types.
System: CPU (User) % is occurs when the CPU usage of the
MongoDB process, as normalized by the number of CPUs, exceeds the
specified threshold.
Common Triggers
Unoptimized queries might lead to
System CPU alerts. Also, your current cluster tier might not
support the current workload.
Fix the Immediate Problem
Consider adding one or more indexes to improve query performance.
Implement a Long-Term Solution
Consider upgrading your cluster to a higher tier to reduce the CPU usage percentage utilized by the current workload. For more information on upgrading a cluster, see Modify a Cluster.
Monitor Your Progress
View the Normalized System CPU chart to monitor CPU usage of all processes on the node, scaled to a range of 0-100% by dividing by the number of CPU cores.
Monitor CPU usage to determine whether data is retrieved from disk instead of memory.
If you are unable to see the usage that triggered the alert, zoom in on the Normalized System CPU chart by clicking and dragging your mouse over the period of interest. With a higher-resolution view you may be able to identify acute spikes in CPU usage that weren't visible in the overview.
To learn more, see View Cluster Metrics.