# Enabling or disabling high availability (HA)
<a name="migrate-topic-disable-ha"></a>

Disable high availability prior to performing any changes on the Conductor nodes.

**To disable high availability on a conductor**:

1. From the Linux prompt, log in to the conductor node with the *elemental* user credentials.

1. Enter the following command to configure the primary Conductor node for HA.

   ```
   [elemental@hostname ~]$ sudo /opt/elemental_se/.support_utils/dbrepl disable
   ```

1. Restart the service using the following commands.

   ```
   [elemental@hostname ~]$ sudo systemctl restart postgresql-15 
   [elemental@hostname ~]$ sudo systemctl restart elemental_se
   ```

1. Enter the following command to verify that Conductor high availability is disabled.

   ```
   [elemental@hostname ~]$ tail -F /opt/elemental_se/web/log/conductor.output
   ```

    The conductor.output log starts to scroll on the screen and shows messages as they are occurring. Watch for the following INFO lines on the primary Conductor node.

   ```
   CONDUCTOR: Initializing environment
   I, [2024-06-04T23:07:54.439807 #131824]  INFO -- : HA environment not enabled
   [2024-06-04 23:08:00 UTC SERVICE]: Elemental Conductor File 2.18.x.x
   ```

1. Enter **Ctrl\$1C** to exit the tail command.

1. Enter the following command, where <day> is today (the day you are upgrading), typed with an initial capital letter: Mon, Tue, Wed, Thu, Fri, Sat, Sun:

   ```
   [elemental@hostname ~]$ sudo tail -F /data/pgsql/logs/postgresql-<day>.log
   ```

1. Confirm that you see this line.

   ```
   database system is ready to accept connections.
   ```

   If the elemental\$1se or postgres process has already started when you starting tailing the logs, you might not see the **ready to accept connections** message. Instead, you could see **rejects connection for host messages** until you upgrade the worker nodes.

1. Enter Ctrl\$1C to exit the tail command.

You must re-enable high availability on the Conductor nodes, to put the nodes back into a redundant configuration. If you have only one Conductor File node, skip this step.

**To enable high availability on the primary Conductor**

1. From the Linux prompt, log in to the primary Conductor node with the *elemental* user credentials.

1. Enter the following command to configure the primary Conductor node for high availability. Where *<dbrepl\$1config\$1file\$1name>* is your dbrepl\$1config.yml file.

   ```
   [elemental@hostname ~]$ sudo /opt/elemental_se/.support_utils/dbrepl configure <dbrepl_config_file_name> primary
   ```

1. Restart the elemental\$1se service.

   ```
   [elemental@hostname ~] sudo systemctl restart elemental_se
   ```

1. Enter the following command to verify that the service is running.

   ```
   [elemental@hostname ~] tail -F /opt/elemental_se/web/log/conductor.output
   ```

   The conductor.output log starts to scroll on the screen and shows messages as they are occurring. Watch for the following three INFO lines on the primary Conductor node.

   ```
   CONDUCTOR: Initializing environment
   I, [2024-06-04T20:58:01.073149 #9844] INFO -- : Configuring the HA environment
   I, [2024-06-04T20:58:03.170375 #9844] INFO -- : Preparing database as replication master
   ...
   [2024-06-04 20:58:09 UTC SERVICE]: Elemental Conductor File 2.18.x.x
   ```

1. Enter Ctrl\$1C to exit the tail command.

1. Enter the following command, where <day> is today (the day you are upgrading), typed with an initial capital letter: Mon, Tue, Wed, Thu, Fri, Sat, Suns.

   ```
   [elemental@hostname ~]$ sudo -s
   [elemental@hostname ~]$ cd /data/pgsql/logs
   [elemental@hostname ~]$ tail -F postgresql-<day>.log
   ```

1. Confirm that you see this line.

   ```
   database system is ready to accept connections.
   ```

   If the elemental\$1se or postgres process has already started when you starting tailing the logs, you might not see the **ready to accept connections message**. Instead, you could see **rejects connection for host messages** until you upgrade the worker nodes.

1. Enter Ctrl\$1C to exit the tail command.

1. Type the following command to exit the session as the sudo user.

   ```
   [elemental@hostname ~]$ exit
   ```

**On the secondary Conductor**

Repeat high availability steps on the secondary Conductor but use the following command instead.

```
[elemental@hostname ~]$ sudo /opt/elemental_se/.support_utils/dbrepl configure <dbrepl_config_file_name> secondary
```