> For the complete MongoDB documentation index, see www.mongodb.com/docs/llms.txt

# Fix CPU Usage Issues

`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](https://www.mongodb.com/docs/atlas/configure-alerts.md#std-label-configure-alerts) page to trigger alerts.

[`System: CPU (Steal) % is`](https://www.mongodb.com/docs/atlas/reference/alert-conditions.md#mongodb-alert-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 (Amazon Web Services) documentation for [AWS burstable instances](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/burstable-performance-instances.html).

**Note:**

The [`System: CPU (Steal) % is`](https://www.mongodb.com/docs/atlas/reference/alert-conditions.md#mongodb-alert-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 [AWS burstable instances](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/burstable-performance-instances.html). Currently, these are `M10` and `M20` cluster types. To learn how burstable performance affects auto-scaling thresholds, see [How Atlas Scales Cluster Tier.](https://www.mongodb.com/docs/atlas/cluster-autoscaling-compute-core.md#std-label-howitworks-scale-cluster-tier)

[`System: CPU (User) % is`](https://www.mongodb.com/docs/atlas/reference/alert-conditions.md#mongodb-alert-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](https://www.mongodb.com/docs/manual/core/query-optimization/) 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](https://www.mongodb.com/docs/manual/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 an Atlas Core Cluster](https://www.mongodb.com/docs/atlas/scale-cluster.md#std-label-modify-cluster) or [Modify an Atlas Infinite Cluster.](https://www.mongodb.com/docs/atlas/infinite/atlas-infinite-modify-cluster.md#std-label-atlas-infinite-modify-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 to scale to a higher cluster tier.

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.](https://www.mongodb.com/docs/atlas/monitor-cluster-metrics.md#std-label-monitor-cluster-metrics)