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A partial restore can also be performed when new data nodes have been added to a MySQL NDB Cluster following a backup. In this case, you can exclude the new nodes using--skip-nodeid when executing therestore cluster command. Consider the MySQL NDB Cluster namedmycluster as shown in the output of the followingshow status command:

mcm> show status -r mycluster;+--------+----------+----------+---------+-----------+-----------+| NodeId | Process  | Host     | Status  | Nodegroup | Package   |+--------+----------+----------+---------+-----------+-----------+| 49     | ndb_mgmd | tonfisk  | stopped |           | mypackage || 1      | ndbd     | tonfisk  | stopped | 0         | mypackage || 2      | ndbd     | tonfisk  | stopped | 0         | mypackage || 50     | mysqld   | tonfisk  | stopped |           | mypackage || 51     | mysqld   | tonfisk  | stopped |           | mypackage || 52     | ndbapi   | *tonfisk | added   |           |           || 53     | ndbapi   | *tonfisk | added   |           |           |+--------+----------+----------+---------+-----------+-----------+7 rows in set (0.03 sec)

The output oflist backups shows us the available backup images for this cluster:

mcm> list backups mycluster;+----------+--------+---------+---------------------+-------+---------+| BackupId | NodeId | Host    | Timestamp           | Parts | Comment |+----------+--------+---------+---------------------+-------+---------+| 1        | 1      | tonfisk | 2020-12-04 12:03:52 | 1     |         || 1        | 2      | tonfisk | 2020-12-04 12:03:52 | 1     |         || 2        | 1      | tonfisk | 2020-12-04 12:04:15 | 1     |         || 2        | 2      | tonfisk | 2020-12-04 12:04:15 | 1     |         || 3        | 1      | tonfisk | 2020-12-04 12:17:41 | 1     |         || 3        | 2      | tonfisk | 2020-12-04 12:17:41 | 1     |         || 4        | 1      | tonfisk | 2020-12-12 14:24:35 | 1     |         || 4        | 2      | tonfisk | 2020-12-12 14:24:35 | 1     |         |+----------+--------+---------+---------------------+-------+---------+8 rows in set (0.06 sec)

Now suppose that, at a later point in time, 2 data nodes have been added tomycluster using anadd process command. Theshow status output formycluster now looks like this:

mcm> show status -r mycluster;+--------+----------+----------+---------+-----------+-----------+| NodeId | Process  | Host     | Status  | Nodegroup | Package   |+--------+----------+----------+---------+-----------+-----------+| 49     | ndb_mgmd | tonfisk  | running |           | mypackage || 1      | ndbd     | tonfisk  | running | 0         | mypackage || 2      | ndbd     | tonfisk  | running | 0         | mypackage || 50     | mysqld   | tonfisk  | running |           | mypackage || 51     | mysqld   | tonfisk  | running |           | mypackage || 52     | ndbapi   | *tonfisk | added   |           |           || 53     | ndbapi   | *tonfisk | added   |           |           || 3      | ndbd     | tonfisk  | running | 1         | mypackage || 4      | ndbd     | tonfisk  | running | 1         | mypackage |+--------+----------+----------+---------+-----------+-----------+9 rows in set (0.01 sec)

Since nodes 3 and 4 were not included in the backup, we need to exclude them when performing the restore. You can causerestore cluster to skip multiple data nodes by specifying a comma-separated list of node IDs with the--skip-nodeid option. Assume that we have just clearedmycluster of MySQL NDB Cluster data using themcm client commandsstop cluster andstart cluster--initial as described previously in this section; then we can restoremycluster (now having 4 data nodes numbered 1, 2, 3, and 4) from backup number 4 (made whenmycluster had only 2 data nodes numbered 1 and 2) as shown here:

mcm> restore cluster --backupid=4 --skip-nodeid=3,4 mycluster;+--------------------------------+| Command result                 |+--------------------------------+| Restore completed successfully |+--------------------------------+1 row in set (17.61 sec)

No data is distributed to the skipped (new) nodes; you must force nodes 3 and 4 to be included in a redistribution of the data usingALTER ONLINE TABLE ... REORGANIZE PARTITION as described previously in this section.

An alternative to generating and running theALTER ONLINE TABLE ... REORGANIZE PARTITION steps is to make use of the logical backup of the NDB tables' metadata, which is part of the cluster backup created by MySQL Cluster Manager. To do this, before you run therestore cluster step outlined above:

You can then run therestore cluster step, and the data is going to be redistributed across all the data nodes, without the need for further manual intervention.