Looker Studio

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Looker Studio can connect to ClickHouse via the MySQL interface using the official Google MySQL data source.

ClickHouse Cloud setup

Select Connect your app

After creating your ClickHouse Cloud Service, on the Connect your app screen, select MySQL from the drop down.

Enable the MySQL interface

Toggle the switch to enable the MySQL interface for this specific service. This will expose port 3306 for this service and prompt you with a MySQL connection screen that includes your unique MySQL username.

Alternatively, in order to enable the MySQL interface for an existing service:

Select Connect

Ensure your service is in Running state then click on the service you want to enable the MySQL interface for. Select "Connect" from the left menu:

Choose MySQL

Select MySQL from the Connect With drop down.

Enable the MySQL interface

Toggle the switch to enable the MySQL interface for this specific service. This will expose port 3306 for this service and prompt you with your MySQL connection screen that include your unique MySQL username.

Creating a readonly MySQL user in ClickHouse Cloud

ClickHouse Cloud automatically creates a mysql4<subdomain> user that shares the same password as the default user. The <subdomain> portion corresponds to the first part of your ClickHouse Cloud hostname.

This username format is required for compatibility with tools that establish secure connections but don't include SNI (Server Name Indication) data in their TLS handshake. Without SNI information, the system cannot perform proper internal routing, so the subdomain hint embedded in the username provides the necessary routing information. The MySQL console client is an example of a tool that requires this.

Tip

A recommended best practice is to create a new readonly MySQL user.

Note

For a ClickHouse Cloud hostname like foobar.us-east1.aws.clickhouse.cloud, the <subdomain> part equals to foobar, and a custom MySQL username could look like mysql4foobar_team1.

Create a readonly settings profile

Create a settings profile to apply to your readonly user, setting the readonly setting to 1:

Create a new readonly MySQL user

Create a user with a name following this format:

Apply the readonly_profile to the new user and make sure that the password is in double SHA1 format. For example:

Grant the new user permissions to access the desired tables

Grant the new user the necessary permissions to interact with the desired tables or databases. For example, if you want to grant access to system.query_log only:

Note

For the readonly user, make sure to only grant SELECT permissions to the tables you want to access.

The newly created user can be used to connect to your ClickHouse Cloud service with the MySQL interface.

Troubleshooting multiple MySQL users in ClickHouse Cloud

If you created a new MySQL user, and you see the following error while connecting via MySQL CLI client:

In this case, ensure that the username follows the mysql4<subdomain>_<username> format, as described (above).

On-premise ClickHouse server setup

Please refer to the official documentation on how to set up a ClickHouse server with enabled MySQL interface.

Aside from adding an entry to the server's config.xml

it is also required to use Double SHA1 password encryption for the user that will be using MySQL interface.

Generating a random password encrypted with Double SHA1 from the shell:

The output should look like the following:

The first line is the generated password, and the second line is the hash we could use to configure ClickHouse.

Here is an example configuration for mysql_user that uses the generated hash:

/etc/clickhouse-server/users.d/mysql_user.xml

Replace password_double_sha1_hex entry with your own generated Double SHA1 hash.

Additionally, it is recommended to use use_mysql_types_in_show_columns to show the native MySQL types instead of ClickHouse ones in SHOW [FULL] COLUMNS query results, which allows BI tools to properly introspect the database schema when using MySQL connectors.

For example:

/etc/clickhouse-server/users.d/mysql_user.xml

or assign it to a different profile instead of the default one.

If you have the mysql binary available, you can test the connection from the commandline. Using the sample username (mysql_user) and password (LZOQYnqQN4L/T6L0) from above the command line would be:

Finally, configure the Clickhouse Server to listen on the desired IP address(es). For example, in config.xml, uncomment out the following to listen on all addresses:

Connecting Looker Studio to ClickHouse

First, login to https://lookerstudio.google.com using your Google account and create a new Data Source:

Search for the official MySQL connector provided by Google (named just MySQL):

Specify your connection details. Please note that MySQL interface port is 9004 by default, and it might be different depending on your server configuration.

Now, you have two options on how to fetch the data from ClickHouse. First, you could use the Table Browser feature:

Alternatively, you could specify a custom query to fetch your data:

Finally, you should be able to see the introspected table structure and adjust the data types if necessary.

Now you can proceed with exploring your data or creating a new report!

Using Looker Studio with ClickHouse Cloud

When using ClickHouse Cloud, you need to enable MySQL interface first. You can do that in connection dialog, "MySQL" tab.

In the Looker Studio UI, choose the "Enable SSL" option. ClickHouse Cloud's SSL certificate is signed by Let's Encrypt. You can download this root cert here.

The rest of the steps are the same as listed above in the previous section.