Back up TF databases¶

To back up the TF databases, use db_json_exim.py, located on the tf-config pods. This script will create a dump of Cassandra and ZooKeeper databases. Cassandra is a fault-tolerant and horizontally scalable database that provides persistent storage of configuration and analytics data. ZooKeeper is used by TF for allocation of unique object identifiers and transactions implementation.

To prevent data loss, Mirantis recommends that you simultaneously back up the ZooKeeper database dedicated to configuration services and the Cassandra database.

To back up TF databases in JSON Format

1. Disable the Neutron server that is used by OpenStack to communicate with the Tungsten Fabric API:

   Note

   The database changes associated with northbound APIs must be stopped on all systems before performing any backup operations.

   1. Scale the neutron-server deployment to 0 replicas:

      kubectl -n openstack scale deploy neutron-server --replicas 0
      

   2. Verify the number of replicas:

      kubectl -n openstack get deploy neutron-server
      

      Example of a positive system response:

      NAME             READY   UP-TO-DATE   AVAILABLE   AGE
      neutron-server   0/0     0            0           6d22h
      

2. Join the Tungsten Fabric API that is part of the config DaemonSet:

   1. Obtain the tf-config pod:

      kubectl -n tf get pod -l tungstenfabric=config
      

      Example of a system response:

      NAME              READY   STATUS    RESTARTS   AGE
      tf-config-6ppvc   5/5     Running   0         5d4h
      tf-config-rgqqq   5/5     Running   0         5d4h
      tf-config-sb4kk   5/5     Running   0         5d4h
      

   2. Join the Bash shell of one of the api container from the previous step:

      kubectl -n tf exec -it tf-config-<hash> -c api -- bash
      

      Example of a system response:

      (config-api[hostname])[<USER>@<HOSTNAME> /]$
      

3. Inside the api container, change the directory to the Python config management packages:

   cd /usr/lib/python2.7/site-packages/cfgm_common
   

4. Back up data using db_json_exim in JSON format:

   python db_json_exim.py --export-to /tmp/db-dump.json
   

5. Verify the created dump:

   cat /tmp/db-dump.json | python -m json.tool | less
   

6. Copy the backup from the container:

   kubectl -n tf cp tf-config-<hash>:/tmp/db-dump.json <DESTINATION-PATH-FOR-BACKUP>
   

7. Enable the Neutron server:

   1. Scale the neutron-server deployment back to the desired number of replicas. Default is 3.

      kubectl -n openstack scale deploy neutron-server --replicas <DESIRED-NUM-REPLICAS>
      

   2. Verify the number of replicas:

      kubectl -n openstack get deploy neutron-server
      

      Example of a system response:

      NAME             READY   UP-TO-DATE   AVAILABLE   AGE
      neutron-server   3/3     3            3           6d23h