Adding NDB Cluster Data Nodes Online Failure during Failure in “Old”  data node Failure in “New”  data node System Failure reorganization is always rolled forward. • If the master fails:  • If the internal commit point has been reached:   The table reorganization is rolled forward. • If the internal commit point has not yet been reached.   The table reorganization is rolled back. reorganization is always rolled forward. • If the master fails:  • If the internal commit point has been reached:   The table reorganization is rolled forward. • If the internal commit point has not yet been reached.   The table reorganization is rolled back. has reached the internal commit point:   When the cluster is restarted, the data and indexes belonging to  table are distributed using the “new”  data nodes. • If the execution of an ALTER TABLE ... REORGANIZE PARTITION statement has not yet reached the internal commit point:   When the cluster is restarted, the data and indexes belonging to  table are distributed using only the “old”  data nodes. Dropping node groups.   The  ndb_mgm  client supports a  DROP NODEGROUP  command, but it is possible to drop a node group only when no data nodes in the node group contain any data. Since there is currently no way to “empty”  a specific data node or node group, this command works only the following two cases: TRUNCATE TABLE  does not work for this purpose because the data nodes continue to store the table definitions. In this section, we list the basic steps required to add new data nodes to an NDB Cluster. This procedure applies whether you are using  ndbd  or  ndbmtd  binaries for the data node processes. For a more detailed example, see Section 23.5.7.3, “Adding NDB Cluster Data Nodes Online: Detailed Example” . Assuming that you already have a running NDB Cluster, adding data nodes online requires the following steps: You must be careful that node IDs for any new data nodes added in the  config.ini  file do not overlap node IDs used by existing nodes. In the event that you have API nodes using dynamically allocated node IDs and these IDs match node IDs that you want to use for new data nodes, it is possible to force any such API nodes to “migrate” , as described later in this procedure. 4481 1. Edit the cluster configuration  config.ini  file, adding new  [ndbd]  sections corresponding to the nodes to be added. In the case where the cluster uses multiple management servers, these changes need to be made to all  config.ini  files used by the management servers. 2. Perform a rolling restart of all NDB Cluster management servers. 1. After issuing  CREATE NODEGROUP  in the  ndb_mgm  client, but before issuing any  ALTER TABLE ... REORGANIZE PARTITION  statements in the  mysql  client. 2. After dropping all  NDBCLUSTER  tables using  DROP TABLE . 23.5.7.2 Adding NDB Cluster Data Nodes Online: Basic procedure