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GitLab Prometheus

Notes:

  • Prometheus and the various exporters listed in this page are bundled in the Omnibus GitLab package. Check each exporter's documentation for the timeline they got added. For installations from source you will have to install them yourself. Over subsequent releases additional GitLab metrics will be captured.
  • Prometheus services are on by default with GitLab 9.0.
  • Prometheus and its exporters do not authenticate users, and will be available to anyone who can access them.

Prometheus is a powerful time-series monitoring service, providing a flexible platform for monitoring GitLab and other software products. GitLab provides out of the box monitoring with Prometheus, providing easy access to high quality time-series monitoring of GitLab services.

Overview

Prometheus works by periodically connecting to data sources and collecting their performance metrics via the various exporters. To view and work with the monitoring data, you can either connect directly to Prometheus or utilize a dashboard tool like Grafana.

Configuring Prometheus

Note: For installations from source you'll have to install and configure it yourself.

Prometheus and it's exporters are on by default, starting with GitLab 9.0. Prometheus will run as the gitlab-prometheus user and listen on http://localhost:9090. Each exporter will be automatically be set up as a monitoring target for Prometheus, unless individually disabled.

To disable Prometheus and all of its exporters, as well as any added in the future:

  1. Edit /etc/gitlab/gitlab.rb
  2. Add or find and uncomment the following line, making sure it's set to false:

    prometheus_monitoring['enable'] = false
  3. Save the file and reconfigure GitLab for the changes to take effect

Changing the port Prometheus listens on

Note: The following change was added in GitLab Omnibus 8.17. Although possible, it's not recommended to change the default address and port Prometheus listens on as this might affect or conflict with other services running on the GitLab server. Proceed at your own risk.

To change the address/port that Prometheus listens on:

  1. Edit /etc/gitlab/gitlab.rb
  2. Add or find and uncomment the following line:

    prometheus['listen_address'] = 'localhost:9090'

    Replace localhost:9090 with the address/port you want Prometheus to listen on.

  3. Save the file and reconfigure GitLab for the changes to take effect

Viewing performance metrics

You can visit http://localhost:9090 for the dashboard that Prometheus offers by default.

Note: If SSL has been enabled on your GitLab instance, you may not be able to access Prometheus on the same browser as GitLab due to HSTS. We plan to provide access via GitLab, but in the interim there are some workarounds: using a separate browser for Prometheus, resetting HSTS, or having Nginx proxy it.

The performance data collected by Prometheus can be viewed directly in the Prometheus console or through a compatible dashboard tool. The Prometheus interface provides a flexible query language to work with the collected data where you can visualize their output. For a more fully featured dashboard, Grafana can be used and has official support for Prometheus.

Sample Prometheus queries:

  • % Memory used: (1 - ((node_memory_MemFree + node_memory_Cached) / node_memory_MemTotal)) * 100
  • % CPU load: 1 - rate(node_cpu{mode="idle"}[5m])
  • Data transmitted: irate(node_network_transmit_bytes[5m])
  • Data received: irate(node_network_receive_bytes[5m])

Configuring Prometheus to monitor Kubernetes

Introduced in GitLab 9.0.

If your GitLab server is running within Kubernetes, Prometheus will collect metrics from the Nodes in the cluster including performance data on each container. This is particularly helpful if your CI/CD environments run in the same cluster, as you can use the [Prometheus project integration][] to monitor them.

To disable the monitoring of Kubernetes:

  1. Edit /etc/gitlab/gitlab.rb
  2. Add or find and uncomment the following line and set it to false:

    prometheus['monitor_kubernetes'] = false
  3. Save the file and reconfigure GitLab for the changes to take effect

Prometheus exporters

There are a number of libraries and servers which help in exporting existing metrics from third-party systems as Prometheus metrics. This is useful for cases where it is not feasible to instrument a given system with Prometheus metrics directly (for example, HAProxy or Linux system stats). You can read more in the Prometheus exporters and integrations upstream documentation.

While you can use any exporter you like with your GitLab installation, the following ones documented here are bundled in the Omnibus GitLab packages making it easy to configure and use.

Node exporter

The node exporter allows you to measure various machine resources such as memory, disk and CPU utilization.

➔ Read more about the node exporter.

Redis exporter

The Redis exporter allows you to measure various Redis metrics.

➔ Read more about the Redis exporter.

Postgres exporter

The Postgres exporter allows you to measure various PostgreSQL metrics.

➔ Read more about the Postgres exporter.

GitLab monitor exporter

The GitLab monitor exporter allows you to measure various GitLab metrics.

➔ Read more about the GitLab monitor exporter.