This page outlines how to set up monitoring for the GRR components. GRR keep tracks of many metrics which can be used to create charts about GRR’s performance, health, and workload.

When Monitoring.http_port is configured, each GRR component exports metrics at http://<host>:<port>/metrics. The export is human-readable plain-text and follows the Open Metrics standard. More importantly however, Prometheus can parse the metrics.

Example Setup

This example will walk you through a basic Prometheus setup. For this example, the GRR Frontend, Worker, and Admin UI will be launched on your local machine. Please refer to Installing GRR Server for a real-world setup.

  1. Install GRR, for example from pip.

  2. Run the GRR components locally. Execute each of the three commands in a separate terminal:

    grr_server --component admin_ui -p Monitoring.http_port=44451
    grr_server --component frontend -p Monitoring.http_port=44452
    grr_server --component worker -p Monitoring.http_port=44453

    Note: Custom monitoring port assignment is only required because the ports would clash when running multiple GRR components on one machine. Prometheus requires to know which type of component listens on which ports. If you use Monitoring.http_port_max, make sure that only one type of GRR components (e.g. only workers) listen on a given range of ports.

  3. Open http://localhost:44451/metrics in your browser. You should see a plain-text list of metrics.

  4. Install Prometheus, e.g. by downloading and unpacking the archive file.

  5. Configure Prometheus to scrape GRR. Save the following configuration as prometheus.yml in the Prometheus folder.

      scrape_interval: 15s
      - job_name: 'grr_admin_ui'
        - targets: ['localhost:44451']
      - job_name: 'grr_frontend'
        - targets: ['localhost:44452']
      - job_name: 'grr_worker'
        - targets: ['localhost:44453']
  6. Start Prometheus, by running the following command from the Prometheus folder:

    ./prometheus --config.file=prometheus.yml
  7. Open http://localhost:9090/targets in your browser. After a couple seconds, you should see three targets (grr_admin_ui, grr_frontend, grr_worker), each having 1 instance up.

  8. Open the Expression Browser by clicking on Graph (http://localhost:9090/graph). On this page, click on the Graph tab (next to Console). Then, try any of the example queries to query GRR metrics. Be aware that you might only see very few data points, very low values, or no data at all since GRR is not under any real workload and has 0 connected clients in this example.

Example Queries

To get you started, this page contains some example queries. These queries give you a good insight on GRRs health and workload.

QPS rate for the Frontend


Latency for requests to the Frontend

rate(frontend_request_latency_sum{job="grr_frontend"}[5m]) /

Active Tasks running on the Frontend


Rate of successful flows on the Worker


Rate of failed flows on the Worker


Threadpool latency in the Worker

rate(threadpool_working_time_sum{job="grr_worker"}[5m]) /

Threadpool queueing time in Worker

rate(threadpool_queueing_time_sum{job="grr_worker"}[5m]) /

Number of outstanding tasks in the Worker


Number of threads running on the Worker


Rate of client crashes reported to the Worker


Real-World Setup

Although Prometheus can display basic charts using the expression browser, we recommend the usage of a dedicated visualization software, e.g. Grafana.

To set up metric-based alerts, refer to Prometheus Alerting and Grafana Alerting.

Prometheus supports automatic Service Discovery for many types of infrastructure. Depending on your hosting setup and size of your GRR installation, this can be an improvement over manually hardcoding hostnames in the Prometheus configuration.

Security Considerations

A minimal HTTP service, based on prometheus_client is listening at Monitoring.http_port for each GRR component. This HTTP service exports read-only metrics under /metrics and /varz and does not enforce any access control. People with access to it can read aggregated metrics about your GRR installation. With these metrics, facts about the number of workers, flow activity, and service health can be derived. Make sure to limit access to the port, for example by employing a firewall. Furthermore, read Prometheus Security.