Understanding Kubernetes Resource Limits
Kubernetes resource limits are an essential part of managing application performance and stability.
By understanding and effectively managing Kubernetes resource limits, organizations can maximize pod performance and ensure optimal application performance and stability.
What are Kubernetes Resource Limits?
Kubernetes resource limits are the maximum amount of resources allocated to a pod, particularly memory, CPU, and storage.
These are essential for managing the performance of applications to avoid overconsumption of system resources, preventing applications from “starving” other applications of resources which leads to stability issues and degraded performance.
This also helps to ensure that applications are not over-provisioned, leading to wasted resources and higher costs.
Resource Limit Management Best Practices
Implementing Kubernetes resource limits can be challenging. Here are some strategies for successful implementation and best practices.
- Create a Baseline — Monitor and analyze resource utilization is vital for understanding the resource usage of applications and determining the appropriate resource limits over a period of time.
- Establish Thresholds — Determine the maximum amount of resources that can be consumed by each pod
- Allocate resources efficiently — Adjust limits as needed so applications are not over-provisioned or under-provisioned. This needs to be evaluated over time for optimal performance and stability.
- Automate resource limit management — Create automation (vertical and horizontal pod autoscaling) that updates resource usage as needed based on meaningful triggers or state changes
- Use Namespaces — Limits can be enforced at the namespace level which restricts the amount of resources pods within that namespace can use
- Limit Pods — Set a maximum number of pods allowed to run on each node to prevent overconsumption of server resources
- Pod Eviction — Remove pods to free resources via eviction policies, such as least recently used (LRU) or Most Requested (MR) policies.
Kubernetes Resource Limit Tools
There are many third party tools for monitoring Kubernetes environments. Here are several to help
- Pod Resource Requirements can be set via the pod manifest file. The Kubernetes scheduler places the pods on nodes that match those requirements.
- Kubernetes has built-in monitoring and logging tools i.e., the Kubernetes Dashboard, that monitors resource performance.
- Prometheus scrapes CPU, memory, pod and node status metrics via the Kubernetes API server, kubelet, or cAdvisor. Grafana can create custom dashboards to display captured performance data.
- Datadog captures Kubernetes performance metrics and provides visualization options to display resource utilization.