Chapter 3. Monitoring CodeReady Workspaces

This chapter describes how to configure CodeReady Workspaces to expose metrics and how to build an example monitoring stack with external tools to process data exposed as metrics by CodeReady Workspaces.

3.1. Enabling and exposing CodeReady Workspaces metrics

This section describes how to enable and expose CodeReady Workspaces metrics.

Procedure

  1. Set the CHE_METRICS_ENABLED=true environment variable, which will expose the 8087 port as a service on the che-master host.

When Red Hat CodeReady Workspaces is installed from the OperatorHub, the environment variable is set automatically if the default CheCluster CR is used:

monitoring che che cluster cr
spec:
  metrics:
    enable: true

3.2. Collecting CodeReady Workspaces metrics with Prometheus

This section describes how to use the Prometheus monitoring system to collect, store and query metrics about CodeReady Workspaces.

Prerequisites

Procedure

  • Configure Prometheus to scrape metrics from the 8087 port:

    Prometheus configuration example

    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'
          static_configs:
            - targets: ['[che-host]:8087']  4

    1
    Rate, at which a target is scraped.
    2
    Rate, at which recording and alerting rules are re-checked (not used in the system at the moment).
    3
    Resources Prometheus monitors. In the default configuration, there is a single job called che-host, which scrapes the time series data exposed by the CodeReady Workspaces server.
    4
    Scrape metrics from the 8087 port.

Verification steps

  • Use the Prometheus console to query and view metrics.

    Metrics are available at: http://<che-server-url>:9090/metrics.

    For more information, see Using the expression browser in the Prometheus documentation.

Additional resources

3.3. Extending CodeReady Workspaces monitoring metrics

This section describes how to create a metric or a group of metrics to extend the monitoring metrics that CodeReady Workspaces is exposing.

There are two major modules for metrics:

  • che-core-metrics-core — contains core metrics module
  • che-core-api-metrics — contains metrics that are dependent on core CodeReady Workspaces components, such as workspace or user managers

Procedure

  • Create a class that extends the MeterBinder class. This allows to register the created metric in the overridden bindTo(MeterRegistry registry) method.

    The following is an example of a metric that has a function that supplies the value for it:

    Example metric

    public class UserMeterBinder implements MeterBinder {

  private final UserManager userManager;

  @Inject
  public UserMeterBinder(UserManager userManager) {
    this.userManager = userManager;
  }

  @Override
  public void bindTo(MeterRegistry registry) {
    Gauge.builder("che.user.total", this::count)
        .description("Total amount of users")
        .register(registry);
  }

  private double count() {
    try {
      return userManager.getTotalCount();
    } catch (ServerException e) {
      return Double.NaN;
    }
  }

    Alternatively, the metric can be stored with a reference and updated manually in some other place in the code.

Additional resources