# Configure MySQL on TurboStack

Enable MySQL on a host, choose a version, and let TurboStack auto-tune memory and provision a database per application.

![The MySQL panel on a host's Services tab, with the Client only toggle, the global MySQL version, and Advanced Settings expanded to show the bind address and InnoDB size|1000](../../assets/screenshots/technologies/mysql.png)

## Where to configure it

MySQL is a host-level service. Open the host, go to its **Services** tab, and select **MySQL**. Enable it and pick the major version. Saving updates the host YAML and provisions Percona Server for MySQL on that host.

## YAML configuration

### Required

| Key | Meaning |
|---|---|
| `mysql_version` | The MySQL major version to install, for example `"8.4"` (or newer). |

### Optional

| Key | Meaning |
|---|---|
| `mysql_innodb_size` | InnoDB buffer pool size. Auto-tuned to the server by default - override only with measured evidence. |
| `mysql_bindaddress` | The address MySQL listens on, or `ANY` for every interface. Security-sensitive: keep it on localhost unless remote access is required. |
| `mysql_timezone` | The database server's default time zone. Uses the server's own time zone when unset. |
| `mysql_server_only` | Makes this host a database server with no local application side. Off by default. |

```yaml
mysql_version: "8.4"

# Optional overrides
mysql_innodb_size: "2G"        # leave unset to keep auto-tuning
mysql_bindaddress: "127.0.0.1" # keep local unless remote access is needed
# mysql_timezone: "UTC"        # leave unset to follow the server's time zone
```

### Listening address

`mysql_bindaddress` takes an address, or the keyword **`ANY`**, which makes MySQL listen on every
interface the server has.

> [!WARNING]
> `ANY` includes any public interface. A database reachable from the internet is a serious risk, so
> prefer a specific private address, and restrict access with the
> [firewall](../firewall/configure.md) whatever you choose.

> [!IMPORTANT]
> On a host that runs **Kubernetes or Docker**, MySQL listens on every interface unless you set
> `mysql_bindaddress` yourself. If that is not what you want, set the address explicitly.

### Time zone

`mysql_timezone` sets the database server's default time zone, which decides how `NOW()`,
`CURDATE()` and `TIMESTAMP` columns are interpreted. Leave it out and MySQL follows the server's
own time zone. Accepted values are what MySQL accepts: `UTC`, or an offset such as `+02:00`.

> [!WARNING]
> Changing the time zone on a database that already holds data shifts how existing `TIMESTAMP`
> values are read back. Decide this when you set the host up, not afterwards.

### Database-server-only hosts

`mysql_server_only: true` turns the host into a dedicated database server: the database engine is
installed, but not the local application-side setup. This is the other half of
[client-only mode](../../platform/hosts/services.md#client-only-mode) - one host runs the database,
one or more others run the applications.

> [!WARNING]
> A `mysql_server_only` host binds MySQL to every interface, because the application servers have
> to reach it. Restrict access with the [firewall](../firewall/configure.md) so that only your own
> servers can connect, and never place such a host on the public internet unprotected.

> [!NOTE]
> MySQL can also run in **client-only mode** when a host needs the MySQL client tools but not a local server - for example to connect to a database on another host.

> [!WARNING]
> Changing `mysql_version` to a higher major version is supported, but **downgrades are not**. Back up first and test the upgrade.

## Common tasks

- [import and export a MySQL database](import-export-database.md)
- [connect to your MySQL database remotely](connect-remotely.md)
- [create and manage database users](manage-database-users.md)
- [use phpMyAdmin](phpmyadmin.md)

## Related

- [What is MySQL?](what-is.md)
- [Services](../../platform/hosts/services.md)
- [Applications overview](../../applications/index.md)