Mirantis Container Cloud (MCC) becomes part of Mirantis OpenStack for Kubernetes (MOSK)!

Starting with MOSK 25.2, the MOSK documentation set covers all product layers, including MOSK management (formerly Container Cloud). This means everything you need is in one place. Some legacy names may remain in the code and documentation and will be updated in future releases. The separate Container Cloud documentation site will be retired, so please update your bookmarks for continued easy access to the latest content.

Troubleshoot cAdvisor alerts¶

This section describes the investigation and troubleshooting steps for the cAdvisor service.

KubeContainersCPUThrottlingHigh

KubeContainersCPUThrottlingHigh¶

Root cause	The alert is based on the metric `container_cpu_cfs_throttled_periods_total` over `container_cpu_cfs_periods_total` and means the percentage of CPU periods where the container ran but was throttled (stopped from running the whole CPU period).
Investigation	The alert usually fires when a Pod starts, often during brief intervals. It may solve automatically once the Pod CPU usage stabilizes. If the issue persists: Obtain the `created_by_name` label from the alert. List the affected Pods using the `created_by_name` label: kubectl get pods -n stacklight -o json \| jq -r '.items[] \| \ select(.metadata.ownerReferences[] \| select(.name=="<created_by_name>")) \| .metadata.name' In the system response, obtain one or more affected Pod names. List the affected containers. Using `<pod_name>` obtained in the previous step, run the following query in the Prometheus query window: sum by (container) (rate(container_cpu_usage_seconds_total{pod="<pod_name>", container!="POD", container!=""}[3m])) Verify the current request and limit difference received from Prometheus with the values from the Pod configuration for every container respectively: kubectl describe <created_by_kind> <created_by_name> In the command above, replace `<created_by_kind>` and `<created_by_name>` with the corresponding alert values. If some of containers lack resources, increase their limits.
Mitigation	As a possible solution, increase Pod limits.

Root cause

The alert is based on the metric container_cpu_cfs_throttled_periods_total over container_cpu_cfs_periods_total and means the percentage of CPU periods where the container ran but was throttled (stopped from running the whole CPU period).

Investigation

The alert usually fires when a Pod starts, often during brief intervals. It may solve automatically once the Pod CPU usage stabilizes. If the issue persists:

Obtain the created_by_name label from the alert.

List the affected Pods using the created_by_name label:

kubectl get pods -n stacklight -o json | jq -r '.items[] | \
select(.metadata.ownerReferences[] | select(.name=="<created_by_name>")) | .metadata.name'

In the system response, obtain one or more affected Pod names.

List the affected containers. Using <pod_name> obtained in the previous step, run the following query in the Prometheus query window:
```
sum by (container) (rate(container_cpu_usage_seconds_total{pod="<pod_name>", container!="POD", container!=""}[3m]))
```
Verify the current request and limit difference received from Prometheus with the values from the Pod configuration for every container respectively:
```
kubectl describe <created_by_kind> <created_by_name>
```
In the command above, replace <created_by_kind> and <created_by_name> with the corresponding alert values.

If some of containers lack resources, increase their limits.

Mitigation

As a possible solution, increase Pod limits.