OpenContrail 3.2: Restore the Cassandra database¶

You may need to restore the Cassandra database after a hardware or software failure.

To restore the Cassandra database:

1. Log in to the Salt Master node.

2. Add the following lines to cluster/opencontrail/control_init.yml:

   cassandra:
     backup:
       client:
         enabled: true
         restore_latest: 1
         restore_from: remote
   

   where:

   • restore_latest can have, for example, the following values:

     • 1, which means restoring the database from the last complete backup.

     • 2, which means restoring the database from the second latest complete backup.

   • restore_from can have the local or remote values. The remote value uses scp to get the files from the cassandra server.

3. Proceed either with automatic restore steps using the Jenkins web UI pipeline or with manual restore steps:

   • Automatic restore steps:

     1. Add the upgrade pipeline to DriveTrain:

        1. Add the following lines to cluster/cicd/control/leader.yml:

           classes:
           - system.jenkins.client.job.deploy.update.restore_cassandra
           

        2. Run the salt -C 'I@jenkins:client' state.sls jenkins.client state.

     2. Log in to the Jenkins web UI.

     3. Open the cassandra - restore pipeline.

     4. Specify the following parameters:

        Parameter	Description and values
        SALT_MASTER_CREDENTIALS	The Salt Master credentials to use for connection, defaults to salt.
        SALT_MASTER_URL	The Salt Master node host URL with the salt-api port, defaults to the jenkins_salt_api_url parameter. For example, http://172.18.170.27:6969.

     5. Click Deploy.

   • Manual restore steps:

     1. Stop the neutron-server service to prevent CRUD API calls during the restore procedure:

        salt -C 'I@neutron:server' service.stop neutron-server
        

     2. Stop the supervisor-config service since the OpenContrail configuration services are actively using Cassandra ConfigDB:

        salt -C 'I@opencontrail:control' service.stop supervisor-config
        

     3. Stop the supervisor-database service on the OpenContrail control nodes:

        salt -C 'I@opencontrail:control' service.stop supervisor-database
        

     4. Remove the Cassandra files on the OpenContrail control nodes:

        salt -C 'I@opencontrail:control' cmd.run 'rm -rf /var/lib/cassandra/*'
        

     5. Start the supervisor-database service on the Cassandra client backup node and wait until the supervisor-database service is up:

        salt -C 'I@cassandra:backup:client' service.start supervisor-database
        salt -C 'I@cassandra:backup:client' cmd.run "service supervisor-database status"
        

     6. Verify the Cassandra cluster status and make sure that all nodes are in the normal UN state :

        salt -C 'I@cassandra:backup:client' cmd.run 'nodetool status'
        

     7. Apply the cassandra state.

        Mirantis recommends running the following command using Linux GNU Screen or alternatives.

        salt -C 'I@cassandra:backup:client' state.sls cassandra
        

        This state restores the databases and creates a file in /var/backups/cassandra/dbrestored.

        Caution

        If you rerun the state, it will not restore the database again. To repeat the restore procedure, first delete the /var/backups/cassandra/dbrestored file and then rerun the cassandra state again.

     8. Verify data load on the Cassandra cluster nodes:

        salt -C 'I@cassandra:backup:client' cmd.run 'nodetool status'
        

        In the nodetool status command output, verify that the Load column has similar values on all nodes. Cassandra should make replication of data between all cluster nodes.

     9. Start the supervisor-config service:

        salt -C 'I@opencontrail:control' service.start supervisor-config
        

     10. Wait for 60 seconds and verify that OpenContrail is in correct state on the control nodes:

         salt -C 'I@opencontrail:control' cmd.run 'contrail-status'
         

     11. Start the neutron-server service:

         salt -C 'I@neutron:server' service.start neutron-server