A system downgrade is a user controlled downgrade to an older version of .               

This procedure can be used after a simplified upgrade. 

To revert to a previously installed version, execute the following procedure:

1. Ensure that the environment variables are set correctly:

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   Example - Extracting the Upgrade Software

   $ export MZ_HOME=/opt/mz 
   $ export JAVA_HOME=/opt/jdk/jdk-17.0.2 
   $ export PATH=$JAVA_HOME/bin:$MZ_HOME/bin:$PATH

2. Disable all workflow groups, either from the Execution Manager in Desktop, or by entering an mzsh command, for example:

   $ mzsh mzadmin/<password> wfgropudisable \*

   Note!

   If you use the wfgroupdisable command, make sure that you enable all system tasks again when you are done.

3. Stop all workflows.
    
4. Shut down all connected Desktops.
    

5. If you want to see which Desktops that are connected, you can use the following command:

   $ mzsh mzadmin/<password> pico -view

   Note!

   This command will also display other pico instances, such as ECs.

6. Shut down the Platform and all ECs.

   $ mzsh shutdown Platform <ec name>  ... 

7. Remove MZ_HOME.

   $ rm -rf $MZ_HOME 

8. Restore the backup of MZ_HOME.

   $ cp -r <backup directory> $MZ_HOME

9. If you are downgrading a system using Oracle, restore the database backup.

   Note!

   If you are using SAP HANA as the Platform database, you will need to disable TLS/SSL on the SAP HANA database before you downgrade your Platform. Refer to Downgrade on the Release Documentation for the steps.

Resume Workflow Execution

1. Set the environment variables JAVA_HOME and PATH according to the system requirements of the restored version.

   Note!

   You must rollback to Java 8 before you downgrade to  8.3 or earlier. 

   Example - Setting Environment Variables

   $ export MZ_HOME=/opt/mz  
   $ export JAVA_HOME=/opt/jdk/jdk1.8.0_121  
   $ export PATH=$JAVA_HOME/bin:$MZ_HOME/bin:$PATH

2. Start the Platform and all ECs.

   $ mzsh startup Platform <ec names>  ...

3. Import the configurations that were exported in the old version prior to the upgrade.      

   $ mzsh mzadmin/<password> systemimport <backup directory>/<filename>

4. Start the real-time workflows.
    
5. Enable the Workflow Groups.