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Monitoring

Available as of v0.3.0

Dashboard Metrics

Harvester has provided a built-in monitoring integration using Prometheus. Monitoring is automatically enabled during the Harvester installations.

From the Dashboard page, users can view the cluster metrics and top 10 most used VM metrics respectively. Also, users can click the Grafana dashboard link to view more dashboards on the Grafana UI.

Note

Only admin users are able to view the cluster dashboard metrics.

VM Detail Metrics

For VMs, you can view VM metrics by clicking on the VM details page > VM Metrics.

Note

The current Memory Usage is calculated based on (1 - free/total) * 100%, not (used/total) * 100%.

For example, in a Linux OS, the free -h command outputs the current memory statistics as follows

$ free -h
              total        used        free      shared  buff/cache   available
Mem:          7.7Gi       166Mi       4.6Gi       1.0Mi       2.9Gi       7.2Gi
Swap:            0B          0B          0B

The corresponding Memory Usage is (1 - 4.6/7.7) * 100%, roughly 40%.

How to Configure Monitoring Settings

Available as of v1.0.1

Monitoring has several components that help to collect and aggregate metric data from all Nodes/Pods/VMs. The resources required for monitoring depend on your workloads and hardware resources. Harvester sets defaults based on general use cases, and you can change them accordingly.

Currently, Resources Settings can be configured for the following components:

  • Prometheus
  • Prometheus Node Exporter(UI configurable as of v1.0.2)

From WebUI

In the Advanced Settings page, you can view and change the resources settings as follows:

  1. Navigate to settings page, find harvester-monitoring.

  2. Click Show harvester-monitoring to view the current values.

  3. Click ⋮ > Edit Setting to set a new value.

  4. Click Save and the Monitoring resource will be restarted within a few seconds. Please be aware that the reboot can take some time to reload previous data.

The most frequently used option is the memory setting:

  • The Requested Memory is the minimum memory required by the Monitoring resource. The recommended value is about 5% to 10% of the system memory of one single management node. A value less than 500Mi will be denied.

  • The Memory Limit is the maximum memory that can be allocated to a Monitoring resource. The recommended value is about 30% of the system's memory for one single management node. When the Monitoring reaches this threshold, it will automatically restart.

Depending on the available hardware resources and system loads, you may change the above settings accordingly.

Note

If you have multiple management nodes with different hardware resources, please set the value of Prometheus based on the smaller one.

Attention

When an increasing number of VMs get deployed on one node, the prometheus-node-exporter pod might get killed due to OOM(out of memory). In that case, you should increase the value of limits.memory.

From CLI

To update those values, you can also use the CLI command with: $kubectl edit managedchart rancher-monitoring -n fleet-local.

For Harvester version >= v1.0.1, the related path and default value are:

# Prometheus configs
spec.values.prometheus.prometheusSpec.resources.limits.cpu: 1000m
spec.values.prometheus.prometheusSpec.resources.limits.memory: 2500Mi
spec.values.prometheus.prometheusSpec.resources.requests.cpu: 750m
spec.values.prometheus.prometheusSpec.resources.requests.memory: 1750Mi
---
# node exporter configs
spec.values.prometheus-node-exporter.resources.limits.cpu: 200m
spec.values.prometheus-node-exporter.resources.limits.memory: 180Mi
spec.values.prometheus-node-exporter.resources.requests.cpu: 100m
spec.values.prometheus-node-exporter.resources.requests.memory: 30Mi

For versions <= v1.0.0, the related path and default value are not specified in the managedchart rancher-monitoring, you need to add them accordingly.

Troubleshooting

For Monitoring support and troubleshooting, please refer to the troubleshooting page .