Adding NDB Cluster Data Nodes Online All management servers must be restarted with the  --reload  or  --initial option to force the reading of the new configuration. If you are using API nodes with dynamically allocated IDs matching any node IDs that you wish to assign to new data nodes, you must restart all API nodes (including SQL nodes) before restarting any of the data nodes processes in this step. This causes any API nodes with node IDs that were previously not explicitly assigned to relinquish those node IDs and acquire new ones. The new data nodes may be started in any order. They can also be started concurrently, as long as they are started after the rolling restarts of all existing data nodes have been completed, and before proceeding to the next step. Exception : For tables created using the  MAX_ROWS  option, this statement does not work; instead, use ALTER TABLE ... ALGORITHM=INPLACE MAX_ROWS=...  to reorganize such tables. You should also bear in mind that using  MAX_ROWS  to set the number of partitions in this fashion is deprecated, and you should use  PARTITION_BALANCE  instead; see Section 13.1.20.11, “Setting NDB_TABLE Options” , for more information. This needs to be done only for tables already existing at the time the new node group is added. Data in tables created after the new node group is added is distributed automatically; however, data added to any given table  tbl  that existed before the new nodes were added is not distributed using the new nodes until that table has been reorganized. This works for space used by variable-width columns of in-memory  NDB  tables.  OPTIMIZE TABLE  is not supported for fixed-width columns of in-memory tables; it is also not supported for Disk Data tables. You can add all the nodes desired, then issue several  CREATE NODEGROUP  commands in succession to add the new node groups to the cluster. In this section we provide a detailed example illustrating how to add new NDB Cluster data nodes online, starting with an NDB Cluster having 2 data nodes in a single node group and concluding with a cluster having 4 data nodes in 2 node groups. 4482 23.5.7.3 Adding NDB Cluster Data Nodes Online: Detailed Example 8. ALTER TABLE ... REORGANIZE PARTITION ALGORITHM=INPLACE  reorganizes partitions but does not reclaim the space freed on the “old”  nodes. You can do this by issuing, for each  NDBCLUSTER table, an  OPTIMIZE TABLE  statement in the  mysql  client. 7. Redistribute the cluster’s data among all data nodes, including the new ones. Normally this is done by issuing an  ALTER TABLE ... ALGORITHM=INPLACE, REORGANIZE PARTITION  statement in the mysql  client for each  NDBCLUSTER  table. 6. Execute one or more  CREATE NODEGROUP  commands in the NDB Cluster management client to create the new node group or node groups to which the new data nodes belong. Note 5. Start the new data nodes. 4. Perform a rolling restart of any SQL or API nodes connected to the NDB Cluster. 3. Perform a rolling restart of all existing NDB Cluster data nodes. It is not necessary (or usually even desirable) to use  --initial  when restarting the existing data nodes. Important