InfluxDB Configuration

CAUTION: InfluxDB is deprecated in favor of Prometheus: InfluxDB support is scheduled to be removed in GitLab 13.0. You are advised to use Prometheus instead.

The default settings provided by InfluxDB are not sufficient for a high traffic GitLab environment. The settings discussed in this document are based on the settings GitLab uses for GitLab.com. Depending on your own needs, you may need to further adjust them.

If you are intending to run InfluxDB on the same server as GitLab, make sure you have plenty of RAM since InfluxDB can use quite a bit depending on traffic.

Unless you are going with a budget setup, it's advised to run it separately.

Requirements

InfluxDB 0.9.5 or newer
A fairly modern version of Linux
At least 4GB of RAM
At least 10GB of storage for InfluxDB data

Note that the RAM and storage requirements can differ greatly depending on the amount of data received/stored. To limit the amount of stored data users can look into InfluxDB Retention Policies.

Installation

Installing InfluxDB is out of the scope of this document. Please refer to the InfluxDB documentation.

InfluxDB Server Settings

Since InfluxDB has many settings that users may wish to customize themselves (e.g. what port to run InfluxDB on), we'll only cover the essentials.

The configuration file in question is usually located at /etc/influxdb/influxdb.conf. Whenever you make a change in this file, InfluxDB needs to be restarted.

Storage Engine

InfluxDB comes with different storage engines and as of InfluxDB 0.9.5 a new storage engine is available, called TSM Tree. All users must use the new tsm1 storage engine as this will be the default engine in upcoming InfluxDB releases.

Make sure you have the following in your configuration file:

[data]
  dir = "/var/lib/influxdb/data"
  engine = "tsm1"

Admin Panel

Production environments should have the InfluxDB admin panel disabled. This feature can be disabled by adding the following to your InfluxDB configuration file:

[admin]
  enabled = false

HTTP

HTTP is required when using the InfluxDB CLI or other tools such as Grafana, thus it should be enabled. When enabling make sure to also enable authentication:

[http]
  enabled = true
  auth-enabled = true

Note: Before you enable authentication, you might want to create an admin user.

UDP

GitLab writes data to InfluxDB via UDP and thus this must be enabled. Enabling UDP can be done using the following settings:

[[udp]]
  enabled = true
  bind-address = ":8089"
  database = "gitlab"
  batch-size = 1000
  batch-pending = 5
  batch-timeout = "1s"
  read-buffer = 209715200

This does the following:

Enable UDP and bind it to port 8089 for all addresses.
Store any data received in the gitlab database.
Define a batch of points to be 1000 points in size and allow a maximum of 5 batches or flush them automatically after 1 second.
Define a UDP read buffer size of 200 MB.

One of the most important settings here is the UDP read buffer size as if this value is set too low, packets will be dropped. You must also make sure the OS buffer size is set to the same value, the default value is almost never enough.

To set the OS buffer size to 200 MB, on Linux you can run the following command:

sysctl -w net.core.rmem_max=209715200

To make this permanent, add the following to /etc/sysctl.conf and restart the server:

net.core.rmem_max=209715200

It is very important to make sure the buffer sizes are large enough to handle all data sent to InfluxDB as otherwise you will lose data. The above buffer sizes are based on the traffic for GitLab.com. Depending on the amount of traffic, users may be able to use a smaller buffer size, but we highly recommend using at least 100 MB.

When enabling UDP, users should take care to not expose the port to the public, as doing so will allow anybody to write data into your InfluxDB database (as InfluxDB's UDP protocol doesn't support authentication). We recommend either whitelisting the allowed IP addresses/ranges, or setting up a VLAN and only allowing traffic from members of said VLAN.

Create a new admin user

If you want to enable authentication, you might want to create an admin user:

influx -execute "CREATE USER jeff WITH PASSWORD '1234' WITH ALL PRIVILEGES"

Create the `gitlab` database

Once you get InfluxDB up and running, you need to create a database for GitLab. Make sure you have changed the storage engine to tsm1 before creating a database.

Note: If you created an admin user and enabled HTTP authentication, remember to append the username (-username <username>) and password (-password <password>) you set earlier to the commands below.

Run the following command to create a database named gitlab:

influx -execute 'CREATE DATABASE gitlab'

The name must be gitlab, do not use any other name.

Next, make sure that the database was successfully created:

influx -execute 'SHOW DATABASES'

The output should be similar to:

name: databases
---------------
name
_internal
gitlab

That's it! Now your GitLab instance should send data to InfluxDB.