StackLight known issues¶

This section lists the StackLight known issues with workarounds for the Mirantis OpenStack for Kubernetes release 21.2.

[13233] Low memory limits for StackLight Helm Controller cause update failure
[12917] prometheus-tf-vrouter-exporter pods fail to start on TF nodes with DPDK

[13233] Low memory limits for StackLight Helm Controller cause update failure¶

During the MOS cluster update to Cluster release 6.14.0, StackLight Helm Controller containers (controller and/or tiller) may get OOMKilled and cause failure to update.

As a workaround, manually increase the default resource requests and limits for stacklightHelmControllerController and stacklightHelmControllerTiller in the StackLight Helm chart values of the Cluster release resource:

resources:
  stacklightHelmControllerController:
    requests:
      cpu: "250m"
      memory: "128Mi"
    limits:
      cpu: "1000m"
      memory: "512Mi"
  stacklightHelmControllerTiller:
    requests:
      cpu: "250m"
      memory: "128Mi"
    limits:
      cpu: "1000m"
      memory: "2048Mi"

For details about resource limits, see Mirantis Container Cloud Operations Guide: Resource limits.

[12917] prometheus-tf-vrouter-exporter pods fail to start on TF nodes with DPDK¶

Fixed in MOS 21.3

StackLight deploys the prometheus-tf-vrouter-exporter exporter based on the node selector matching the tfvrouter: enabled node label. The Tungsten Fabric nodes with DPDK have the tfvrouter-dpdk: enabled label set instead. Therefore, the prometheus-tf-vrouter-exporter exporter fails to start on these nodes.

Workaround:

Add the tfvrouter-fix: enabled label to every node that contains either the tfvrouter: enabled or the tfvrouter-dpdk: enabled node label.
```
kubectl label node <node_name> tfvrouter-fix=enabled
```
In the Cluster release resource, specify the following nodeSelector definition in the StackLight Helm chart values:
```
nodeSelector:
  component:
    tfVrouterExporter:
        tfvrouter-fix: enabled
```

Once done, prometheus-tf-vrouter-exporter will be deployed to every node with the tfvrouter-fix: enabled label.