> [!CAUTION]
> **Caution:** This documentation covers Edge for Private Cloud 4.18.01, which is no longer supported. Google does not provide security patches, bug fixes, or technical support for this version. The current supported version is 4.54.00. See the [Edge for Private Cloud documentation](https://docs.apigee.com/private-cloud/latest/overview) for the current version, or [All versions](https://docs.apigee.com/private-cloud/versions) to compare releases.

*Edge for Private Cloud v4.18.01*

You can enable debug logging for several Edge components. When you enable debug logging,
the component writes debug messages to its system.log file.

For example, if you enable debug logging for the Edge Router, the Router writes debug messages
to:

```
/opt/apigee/var/log/edge-router/logs/system.log
```

> [!NOTE]
> **Note:** Enabling debug logging can cause the system.log file for a component to grow very large in size, and can affect the overall system performance. It is recommended that you enable debug logging for only as long as necessary, and then disable it.

Use the following API call to enable debug logging for a component:

```
curl -X POST "http://localhost:PORT/v1/logsessions?session=debug"
```

To disable debug logging:

```
curl -X DELETE "http://localhost:PORT/v1/logsessions/debug"
```

To view active debug logging sessions:

```
curl -X GET "http://localhost:PORT/v1/logsessions/debug"
```

> [!WARNING]
> **Warning:** Notice that these calls do not take credentials and refer to localhost. These API calls must be run on the server hosting the Edge components; they cannot be run remotely.

Each Edge component that supports debug logging uses a different port number in the API call,
as shown in the following table:

| **Component** | **Port** | **Log file** |
|---|---|---|
| Management Server | 8080 | /opt/apigee/var/log/edge-management-server/logs/system.log |
| Router | 8081 | /opt/apigee/var/log/edge-router/logs/system.log |
| Message Processor | 8082 | /opt/apigee/var/log/edge-message-processor/logs/system.log |
| Qpid Server | 8083 | /opt/apigee/var/log/edge-qpid-server/logs/system.log |
| Postgres Server | 8084 | /opt/apigee/var/log/edge-postgres-server/logs/system.log |

## Enable debug logging for Edge SSO

To enable debug logging for Edge SSO:

1. Edit the `/opt/apigee/customer/application/sso.properties` file (if the file does not exist, create it):

   ```
   > vi /opt/apigee/customer/application/sso.properties
   ```
2. Set the following property and save the file:

   ```
   conf_logback_log_level=DEBUG
   ```
3. Restart Edge SSO:

   ```
   > /opt/apigee/apigee-service/bin/apigee-service edge-sso restart
   ```