Grafana is a powerful visualisation tool that we can use to display graphics of the persisted data.

You can easily connect Grafana to either the QuantumLeap CrateDB or Timescale back end to visualise QuantumLeap data on your dashboards. In both cases, the Grafana data source to use is the Postgres Datasource which normally ships with recent versions of Grafana.

If you followed the Installation Guide, you have already Grafana running in a Docker container. If deployed locally, it's probably at

If you're using the CrateDB back end, we suggest you read this blog post and follow Crate's recommendations on how to configure the Grafana datasource which we have summarised in the below section.

Configuring the DataSource for CrateDB

Explore your deployed Grafana instance (e.g If you didn't change the defaults credentials, use admin as both user and password.

Go to Add data source, select PostreSQL and fill in the required fields, with the following considerations:

  • Name: This is the name you want for the Datasource. Name it CrateDB and make it default.
  • Host: The full url where CrateDB was deployed, but on port 5432. In the docker-compose example, this should be crate:5432.
  • Database: This is the name of the database schema. By default, crate uses doc schema, but if you are using multi-tenancy headers, the schema will be defined by the tenant of the entity type. More info in the Multi-tenancy section.
  • User: Use crate user.
  • SSL Mode: disable.

The following image shows an example of how the datasource configuration should look like alt text

Click Save & Test and you should get an OK message.

Configuring the DataSource for PostgreSQL

The process is pretty much the same as outlined above and is well documented in the Grafana PosgreSQL data source manual. Note that you should enable the TimescaleDB data source option.

Using the DataSource in your Graph

Having your datasource setup, you can start using it in the different visualisation widgets.

The following is an example of a simple Graph using a datasource connected to CrateDB. Note the selection of the datasource (called CrateDB in this case), as well as the specification of the table in the from field.

Note table names are prefixed by et. See the Data Retrieval section to know how table names are defined, but you should recognise the entity type.

Note the name of the column used as time index is time_index, as explained in the Time Index section.

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