Limitations for Windows integration

This page provides information about limitations and troubleshooting for New Relic's Kubernetes integration when running on Windows-based nodes.

Checking the Windows Version

To check your Windows version, open a Powershell or command prompt window, and run:

$
systeminfo

Look for the lines beginning with OS Name and OS Version. These lines provide the OS information and build number. This check is only to confirm that your environment is compatible; you don't need to specify this version information during installation.

• Windows Server LTSC 2019: Corresponds to build number 10.0.17763.
• Windows Server LTSC 2022: Corresponds to build number 10.0.20348.

Windows DaemonSets

When Windows monitoring is enabled, a Kubernetes DaemonSet is created for each supported Windows version, but pods are created only for Windows node versions that exist in the cluster. This means you may see multiple Windows-specific DaemonSets, but not all of them will have a "desired" pod count.

For example, in a cluster with two Linux nodes, one Windows LTSC 2022 node, and no Windows LTSC 2019 nodes, the output would be similar to this:

$
kubectl -n newrelic get daemonsets
$
NAME                                                DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR                                                          AGE
$
<...snip...>
$
newrelic-bundle-nrk8s-kubelet                       2         2         2       2            2           kubernetes.io/os=linux                                                 24h
$
newrelic-bundle-nrk8s-kubelet-windows-ltsc2019      0         0         0       0            0           kubernetes.io/os=windows,node.kubernetes.io/windows-build=10.0.17763   24h
$
newrelic-bundle-nrk8s-kubelet-windows-ltsc2022      1         1         1       1            1           kubernetes.io/os=windows,node.kubernetes.io/windows-build=10.0.20348   24h

If you want, you can prevent the chart from creating unnecessary DaemonSets by including the windowsOsList key in your custom values.yaml file while installing via Helm Chart and specifying only the desired version:

windowsOsList:
  - version: ltsc2022                      # Human-readable version identifier
    imageTagSuffix: ltsc2022               # Tag to be used for nodes running the windows version above
    buildNumber: 10.0.20348                # Build number for the nodes running the version above. Used as a selector.

Limitations to the Kubernetes integration for Windows

The New Relic agent for Windows sends Kubernetes data samples, such as K8sNodeSample and K8sPodSample. The limitations that apply depend on whether you are running in privileged (HostProcess) mode or unprivileged mode.

Unprivileged mode limitations

When running in unprivileged mode (windows.privileged=false), standard Windows container isolation prevents the agent from directly accessing host resources. The following samples are not generated:

• SystemSample
• StorageSample
• NetworkSample
• ProcessSample

Additionally, hostNetwork: true cannot be set in the pod spec for standard Windows containers. This is a Kubernetes limitation that doesn't apply when using HostProcess pods in privileged mode.

Windows kubelet metric gaps

The following Kubernetes metrics are unavailable on all Windows nodes regardless of mode, because the Windows kubelet either doesn't expose them or they're not applicable on Windows:

• Node:
  • memoryMajorPageFaultsPerSecond: Always returns 0.
  • memoryPageFaults: Always returns 0.
  • memoryRssBytes: Always returns 0.
  • net.errorsPerSecond: Not sent.
  • net.rxBytesPerSecond: Not sent.
  • net.txBytesPerSecond: Not sent.
  • Not relevant for Windows:
    • fsInodes: Not sent.
    • fsInodesFree: Not sent.
    • fsInodesUsed: Not sent.
    • runtimeInodes: Not sent.
    • runtimeInodesFree: Not sent.
    • runtimeInodesUsed: Not sent.
• Container:
  • containerID: Not sent.
  • containerImageID: Not sent.
  • memoryMappedFileBytes: Not sent.
  • memoryUsedBytes: Not sent. Use memoryWorkingSetBytes as an alternative.
  • memoryUtilization: Not sent (relies on memoryUsedBytes). You can compute a similar metric using memoryWorkingSetBytes/memoryLimitBytes.
  • requestedMemoryUtilization: Not sent (relies on memoryUsedBytes). You can compute a similar metric using memoryWorkingSetBytes/memoryRequestedBytes.
  • Not relevant for Windows:
    • cpuCfs*: All cpuCfs* values not sent.
• Volume:
  • fsUsedBytes: Always returns 0.
  • fsUsedPercent: Always returns 0 (relies on fsUsedBytes).