Tungsten Clustering

Downgrading to an Earlier Release

If after upgrading Tungsten Cluster you are experiencing problems, and Continuent Support have suggested that you downgrade to an earlier version, follow these steps to revert your existing installation.

Redirect all users directly to the MySQL server on the Primary. This may require changing applications and clients to point directly to the MySQL servers. You cannot use Tungsten Connector to handle this for you, since the entire cluster, including the Tungsten Connector services, will be removed.
Stop Tungsten services on all servers:
```
shell> stopall
```
Extract the release of Tungsten Cluster that should be installed instead, if not already done so
If installed via the Staging Method, use tpm fetch to retrieve the current configuration. Skip to the next step if installed via the INI method.
```
shell> ./tools/tpm fetch --user=tungsten --hosts=host1,host2,host3,host4 --release-directory=/opt/continuent
```
Note
In the event that the tpm fetch operation fails to detect the current configuration, run tpm reverse on one of the machines in the configured service. This will output the current configuration. If necessary, execute tpm reverse on multiple hosts to determine whether the information matches.
If you execute the returned text from tpm reverse, it will configure the service within the local directory, and the installation can then be updated.
Ensure that the current Primary is listed as the Primary within the configuration.
Change into the correct release directory, and update Tungsten Cluster to deploy the new release, if running an INI deployment, you will need to execute this on all servers:
```
shell> cd /opt/continuent/software/tungsten_clustering-7.1.4-81/
shell> ./tools/tpm update --replace-release
```
Start all the services on the Primary:
```
shell> startall
```
Confirm that the current Primary is correct within trepctl and cctrl.
Start the services on remaining servers:
```
shell> startall
```
Once all the services are back up and running, it is safe to point users and applications at Tungsten Connector and return to normal operations.