How to view metrics

You can view Charmed MongoDB K8s metrics in two ways:

• Querying the metric endpoint directly
• Viewing them in Grafana

Query the metric endpoint

Charmed MongoDB K8s comes with MongoDB Exporter and provides replication and cluster metrics. The metrics can be queried by accessing the http://<unit-ip>:9216/metrics endpoint.

To quickly view them, you can do the following:

1. Identify the unit you would like to query by entering juju status. Choose a unit to gather metrics from and copy its “Public Address”
2. curl the metrics endpoint for your unit of interest with curl http://<unit-ip>:9216/metrics. This should show a long set of metrics.

Access metrics with Grafana

Charmed MongoDB K8s provides integration with the Canonical Observability Stack (COS) - which allows you to view the metrics in a GUI.

To view the GUI:

1. Deploy the cos-lite bundle in a Kubernetes environment. This can be done by following the deployment tutorial. Wait for the cos-lite bundle to become active and idle, by viewing juju status. Beware to use the following offers which contain the prometheus-scrape endpoint, essential to our stack (this endpoint still exists but has been removed from the example offer of the bundle):

https://raw.githubusercontent.com/canonical/cos-lite-bundle/09715997467e1b568109064fa17ecefd4b574032/overlays/offers-overlay.yaml
https://raw.githubusercontent.com/canonical/cos-lite-bundle/09715997467e1b568109064fa17ecefd4b574032/overlays/storage-small-overlay.yaml

2. Switch back to your model and consume offers from the COS bundle and relate COS bundle to your application:

juju consume <cos-controller-name>:admin/cos.prometheus-scrape
juju consume <cos-controller-name>:admin/cos.alertmanager-karma-dashboard
juju consume <cos-controller-name>:admin/cos.grafana-dashboards
juju consume <cos-controller-name>:admin/cos.loki-logging
juju consume <cos-controller-name>:admin/cos.prometheus-receive-remote-write

juju integrate mongodb-k8s prometheus-scrape
juju integrate mongodb-k8s loki-logging
juju integrate mongodb-k8s grafana-dashboards

3. To view the dashboard we need to find the URL of grafana along with the password for the dashboard. Switch to the k8s model hosting the COS-lite bundle and show all applications:

juju switch <cos-controller>
juju status

Under the report of juju status, the IP address of the grafana GUI should be listed as the “Public Address” for the application grafana. Copy this address and navigate to it in your browser. In your browser you should see a login. Use the username admin, to retrieve the password go back to your terminal and run the action: juju run grafana/0 get-admin-password --wait - use this password to access the Grafana Dashboard.