Monitoring Che Server

You can configure Che to expose JVM metrics such as JVM memory and class loading for Che Server.

Enabling and exposing Che Server metrics

Che exposes the JVM metrics on port 8087 of the che-host Service. You can configure this behaviour.

Procedure

Configure the CheCluster Custom Resource. See Using the CLI to configure the CheCluster Custom Resource.
```
spec:
  components:
    metrics:
      enable: <boolean> (1)
```
1 true to enable, false to disable.

Collecting Che Server metrics with Prometheus

To use Prometheus to collect, store, and query JVM metrics for Che Server:

Prerequisites

Che is exposing metrics on port 8087. See Enabling and exposing Che server JVM metrics.
Prometheus 2.26.0 or later is running. The Prometheus console is running on port 9090 with a corresponding Service. See First steps with Prometheus.

Procedure

Configure Prometheus to scrape metrics from port 8087.

The example monitoring stack already creates the prometheus-config ConfigMap with an empty configuration. To provide the Prometheus configuration details, edit the data field of the ConfigMap.

Example 1. Prometheus configuration

apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
data:
  prometheus.yml: |-
      global:
        scrape_interval:     5s             (1)
        evaluation_interval: 5s             (2)
      scrape_configs:                       (3)
        - job_name: 'Che Server'
          static_configs:
            - targets: ['che-host.<Che_namespace>:8087']  (4)

1	The rate at which a target is scraped.
2	The rate at which the recording and alerting rules are re-checked.
3	The resources that Prometheus monitors. In the default configuration, a single job, `Che Server`, scrapes the time series data exposed by Che Server.
4	The scrape target for the metrics from port `8087`. Replace `<Che_namespace>` with the Che namespace. The default Che namespace is `eclipse-che`.

Scale the Prometheus Deployment down and up to read the updated ConfigMap from the previous step.

$ kubectl scale --replicas=0 deployment/prometheus -n monitoring && kubectl scale --replicas=1 deployment/prometheus -n monitoring

Verification

Use port forwarding to access the Prometheus Service locally:

$ kubectl port-forward svc/prometheus 9090:9090 -n monitoring

Verify that all targets are up by viewing the targets endpoint at localhost:9090/targets.
Use the Prometheus console to view and query metrics:
- View metrics at localhost:9090/metrics.
- Query metrics from localhost:9090/graph.
  
  For more information, see Using the expression browser.

Additional resources

Viewing Che Server metrics on Grafana dashboards

To view the Che Server metrics on Grafana:

Prerequisites

Prometheus is collecting metrics on the Che cluster. See Monitoring Che with Prometheus and Grafana.
Grafana 6.0 or later is running on port 3000 with a corresponding Service. See Installing Grafana.

Procedure

Add the data source for the Prometheus instance. See Creating a Prometheus data source.
Import the example dashboard. See Import dashboard.
View the Che JVM metrics in the Grafana console:

Figure 1. Che server JVM dashboard

Figure 2. Quick Facts

Figure 3. JVM Memory

Figure 4. JVM Misc

Figure 5. JVM Memory Pools (heap)

Figure 6. JVM Memory Pools (Non-Heap)

Figure 7. Garbage Collection

Figure 8. Class loading

Figure 9. Buffer Pools