## Troubleshooting on-premises database connectivity

URL: https://docs.atlan.com/apps/connectors/database/on-premises-databases/troubleshooting/troubleshooting-on-premises-database-connectivity

> Learn about troubleshooting on-premises database connectivity.

:::danger **Deprecated**
This job execution mode was deprecated on June 30, 2026 and is no longer supported or maintained, including bug fixes. Existing workflows may break/be disabled without warning. For all implementations, switch to [Self-deployed runtime](https://docs.atlan.com/llms/platform/self-deployed-runtime/llms.txt).
:::

#### No internet access on server running metadata-extractor

The metadata-extractor attempts to download missing JDBC drivers. If there is no internet connection available on the server running Docker Compose, the metadata-extractor won't be able to get the required drivers.

To make these drivers available without an internet connection:

1. Download the latest JDBC driver from the database vendor.
2. Copy the JDBC driver files to the server running Docker Compose into a dedicated directory. Use a sub-directory under where your compose file exists (for example, `./jdbc/`).
3. Extract the files in that sub-directory: `tar -zxvf postgres.tar.gz mysql.tar.gz`
4. Change your compose file to mount this sub-directory for each service you've defined.

For example, the compose file may look something like this:

```
services:
 my-database:
 # ...
 volumes:
 - :/jars
 - ./output/my-database:/output
```

(Replace `` with the sub-directory where you extracted the drivers: `./jdbc` in the example.)

Once you've followed these steps you can run `sudo docker-compose up` as usual. The metadata-extractor now use these local drivers, so internet access is no longer necessary.

#### I need local DNS to resolve my server addresses

To specify a DNS server for the metadata-extractor to use in resolving server names:

- Add a `dns` element to your service definitions in the compose file.

For example, the compose file may look something like this:

```
services:
 my-database:
 <<: *extract
 environment:
 # ...
 volumes:
 # ...
 dns:
 - 
```

(Replace `` with the IP address of your local DNS server.)

#### In need to connect to localhost

So that metadata-extractor can access a service running on the same server as Docker Compose:

- On Linux, use `localhost` as the `HOST` value.
- On Windows and Mac, use `host.docker.internal` as the `HOST` value.

More details are available in the Docker article: [I want to connect from a container to a service on the host](https://docs.docker.com/desktop/networking/#i-want-to-connect-from-a-container-to-a-service-on-the-host)

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