Kubelet Health Test

Monitoring Kubelet health is crucial because the Kubelet is the primary agent responsible for managing containers on each Kubernetes node. If a Kubelet fails or performs poorly, it can lead to issues like unresponsive or unhealthy pods, increased downtime, and degraded application performance. By tracking its health, you ensure timely detection of issues such as resource exhaustion, network problems, or configuration errors. This proactive monitoring helps maintain cluster stability, reliability, and performance, allowing for quick remediation and minimizing disruptions in service.

The Kubelet Health Test continuously monitors the Kubelet in the target node and reports key metrics like health, endpoint availability, response time etc. These metrics are invaluable for the administrators to ensure that service is up and prevent any issues in case service has problems.

Target of the test : A Kubernetes Worker Node

Agent deploying the test : A remote agent

Outputs of the test : One set of results for the target Kubernetes Worker node being monitored

Configurable parameters for the test

Parameter	Description
Test Period	How often should the test be executed.
Host	The IP address of the host for which this test is to be configured.
Port	Specify the port at which the specified Host listens. By default, this is 6443.
Timeout	Specify the duration (in seconds) beyond which the test will timeout in the Timeout text box. The default value is 10 seconds.
Health URL	The Kubernetes API server has a built-in health check endpoint. Enter the Health URL in Health URL text box.
Metric URL	Each of the Kubernetes system components expose monitoring metrics through /metrics endpoint of the HTTP server. For components that don't expose endpoint by default, refer official Kubernetes distribution documentation site. Specify the metric URL textbox.
Detailed Diagnosis	To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option. The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled: The eG manager license should allow the detailed diagnosis capability Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Health	Indicates the health of Kubelet agent on target Kubernetes node.		The values that this measure reports and their corresponding numeric values are detailed in the table below: Measure Value Numeric Value Not ok 0 Ok 5 Note: By default, this test reports the Measure Values listed in the table above to indicate the Health of Kubelet service on the target node. In the graph of this measure however, the state is indicated using the numeric equivalents only.
Endpoint availability	Indicates the percentage of endpoints available in the target node.	Percentage	If the percentage availability of endpoints is low, this will result in low performance and needs to be investigated.
Endpoint response time	Indicates the response time of Kubelet endpoints.	Milliseconds	If the end point response times are above the threshold, this needs to be investigates.
Metric endpoint availability	Indicates the percentage of metric endpoints available in the target node.	Percentage	If the percentage availability of metric endpoints is low, this will result in low performance and needs to be investigated.
Metric endpoint response time	Indicates the response time of Kubelet metric endpoints.	Milliseconds	If the metric end point response times are above the threshold, this needs to be investigates.
Metric endpoint response size	Indicates the response time of Kubelet metric endpoints size.	KB