Enable monitoring

Both Charmed Apache Kafka and Charmed Apache ZooKeeper come with the JMX exporter. The metrics can be queried by accessing the http://<kafka-unit-ip>:9101/metrics and http://<zookeeper-unit-ip>:9998/metrics endpoints, respectively.

Additionally, the charm provides integration with the Canonical Observability Stack.

Deploy the cos-lite bundle in a Kubernetes environment. This can be done by following the deployment tutorial. Since the Charmed Apache Kafka is deployed directly on a cloud infrastructure environment, it is needed to offer the endpoints of the COS relations. The offers-overlay can be used, and this step is shown in the COS tutorial.

Offer interfaces via the COS controller

Switch to COS K8s environment and offer COS interfaces to be cross-model related with Charmed Apache Kafka VM model:

# Switch to Kubernetes controller, for the cos model.
juju switch <k8s_controller>:<cos_model_name>

juju offer grafana:grafana-dashboard grafana-dashboards
juju offer loki:logging loki-logging
juju offer prometheus:receive-remote-write prometheus-receive-remote-write

Consume offers via the Apache Kafka model

Switch to Charmed Apache Kafka VM model, find offers and relate with them:

# We are on the Kubernetes controller, for the cos model. Switch to kafka model
juju switch <machine_controller_name>:<kafka_model_name>

juju find-offers <k8s_controller>:

A similar output should appear, if k8s is the K8s controller name and cos the model where cos-lite has been deployed:

Store      URL                                        Access  Interfaces
k8s        admin/cos.grafana-dashboards               admin   grafana_dashboard:grafana-dashboard
k8s        admin/cos.loki-logging                     admin   loki_push_api:logging
k8s        admin/cos.prometheus-receive-remote-write  admin   prometheus-receive-remote-write:receive-remote-write
...

Consume offers to be reachable in the current model:

juju consume <k8s_controller>:admin/<cos_model_name>.prometheus-receive-remote-write
juju consume <k8s_controller>:admin/<cos_model_name>.loki-logging
juju consume <k8s_controller>:admin/<cos_model_name>.grafana-dashboards

Now, deploy grafana-agent (subordinate charm) and relate it with Charmed Apache Kafka and Charmed Apache ZooKeeper:

juju deploy grafana-agent
juju relate kafka:cos-agent grafana-agent
juju relate zookeeper:cos-agent grafana-agent

Finally, relate grafana-agent with consumed COS offers:

juju relate grafana-agent grafana-dashboards
juju relate grafana-agent loki-logging
juju relate grafana-agent prometheus-receive-remote-write

Wait for all components to settle down on a active/idle state on both models, e.g. <kafka_model_name> and <cos_model_name>.

After this is complete, the monitoring COS stack should be up and running and ready to be used.

Connect Grafana web interface

To connect to the Grafana web interface, follow the Browse dashboards section of the MicroK8s “Getting started” guide.

juju run grafana/leader get-admin-password --model <k8s_cos_controller>:<cos_model_name>

Tune server logging level

To tune the level of the server logs for Apache Kafka and Apache ZooKeeper, configure the log-level and log_level properties accordingly.

Apache Kafka

juju config kafka log_level=<LOG_LEVEL>

Possible values are ERROR, WARNING, INFO, DEBUG.

Apache ZooKeeper

juju config zookeeper log-level=<LOG_LEVEL>

Possible values are ERROR, WARNING, INFO, DEBUG.