> [!CAUTION]
> **Caution:** This documentation covers Edge for Private Cloud 4.19.06, 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.

You can install multiple instances of the Edge UI in a high availability scenario. However,
after installing the two instances of the Edge UI, you must perform post-installation tasks in
order to synchronize the property settings between the two.

Specifically, you must configure the two UI instances to have the same value for the following
properties:

```
application.secret=value
mail.smtp.credential=value
apigee.mgmt.credential=value
```

Additionally, if you configure them to use TLS, then you must ensure that you use the same
cert and key on both instances.

## Configure Edge UI instances using HTTP

1. Log in to the node hosting the first Edge UI instances (do not log in to the UI itself, but as a user on the node).
2. Open `/opt/apigee/edge-ui/conf/apigee.conf` in an editor and copy the values of the following properties for later use:

   ```
   mail.smtp.credential="value"
   apigee.mgmt.credential="value"
   ```
3. Open `/opt/apigee/edge-ui/conf/application.conf` in an editor and copy the values of the following property for later use:

   ```
   application.secret="value"
   ```
4. Log in to the node hosting the second Edge UI instances.
5. Open `/opt/apigee/customer/application/ui.properties` on the second UI instance in an editor. If the file does not exist, create it.
6. Add the following properties to `/opt/apigee/customer/application/ui.properties`, including the values that you copied from the first UI instance:

   ```
   conf_application_application.secret="value"
   conf_apigee_mail.smtp.credential="value"
   conf_apigee_apigee.mgmt.credential="value"
   ```

   Notice how you prefix these values with either `conf_application_` or
   `conf_apigee_`.
7. Save the file.
8. Make sure `/opt/apigee/customer/application/ui.properties` is owned by the "apigee" user:

   ```
   chown apigee:apigee /opt/apigee/customer/application/ui.properties
   ```
9. Restart the second UI instance:

   ```
   /opt/apigee/apigee-service/bin/apigee-service edge-ui restart
   ```

Users can now log in to either UI instance.

## Configure Edge UI instances
using TLS/HTTPS

1. Configure the first UI instance to use TLS/HTTPS as described in [Configuring TLS for the management UI](https://docs.apigee.com/private-cloud/v4.19.06/configuring-ssl-management-ui).
2. Configure the second Edge UI instances as described above for HTTP to synchronize the required properties.
3. Copy the JKS file containing the cert and key from the first UI instance to the node hosting the second UI instance.
4. Configure the second UI instance to use TLS/HTTPS as described in [Configuring TLS for the management UI](https://docs.apigee.com/private-cloud/v4.19.06/configuring-ssl-management-ui).