OpenShift is a powerful open-source container application platform developed by Red Hat. It enables developers to build, deploy, and manage containerized applications seamlessly. OpenShift leverages Kubernetes for orchestration, providing a robust environment for scaling applications and managing workloads efficiently.
When working with OpenShift, you might encounter a situation where your pods are unexpectedly evicted. This is typically indicated by the status PodEvicted in the OpenShift console or when querying pod statuses using the CLI. This symptom suggests that the pod was removed from the node due to resource constraints.
The PodEvicted status occurs when a pod is forcibly terminated by the system due to insufficient resources on the node it resides on. This is a common scenario in environments with high resource utilization or misconfigured resource requests and limits. The Kubernetes scheduler evicts pods to free up resources for higher-priority workloads or to maintain node stability.
To address PodEvicted issues, consider the following steps:
Begin by checking the resource utilization of nodes to identify any bottlenecks. Use the following command to view node resource usage:
oc adm top nodes
This command provides an overview of CPU and memory usage across nodes. If nodes are consistently running at high capacity, consider scaling your cluster by adding more nodes.
Ensure that your pods have appropriate resource requests and limits defined. Misconfigured requests can lead to resource contention and eviction. Review and adjust these settings in your pod specifications:
resources:
requests:
memory: "64Mi"
cpu: "250m"
limits:
memory: "128Mi"
cpu: "500m"
For more information on configuring resource requests and limits, refer to the OpenShift documentation.
Consider implementing pod priority and preemption policies to ensure critical workloads are prioritized. This can help prevent important pods from being evicted in favor of less critical ones. Learn more about configuring pod priority in the Kubernetes documentation.
By understanding the causes of PodEvicted issues and implementing the recommended solutions, you can enhance the stability and reliability of your OpenShift environment. Regularly monitor resource usage and adjust configurations to prevent future occurrences. For further assistance, consult the Red Hat OpenShift documentation.
(Perfect for DevOps & SREs)
(Perfect for DevOps & SREs)
