Commands in the NDB Cluster Management Client Normally,  RESTART  fails if taking the node offline would result in an incomplete cluster. The  -f  option forces the node to restart without checking for this. If this option is used and the result is an incomplete cluster, the entire cluster is restarted. Displays status information for the data node identified by  node_id  (or for all data nodes). The output from this command also indicates when the cluster is in single user mode. Displays a report of type  report-type  for the data node identified by  node_id , or for all data nodes using  ALL . Currently, there are three accepted values for  report-type : This information is also available from the  ndbinfo.memoryusage  table. report-type  is case-insensitive and “fuzzy” ; for  MemoryUsage , you can use  MEMORY  (as shown in the prior example),  memory , or even simply  MEM  (or  mem ). You can abbreviate  BackupStatus  in a similar fashion. Enters single user mode, whereby only the MySQL server identified by the node ID  node_id  is permitted to access the database. Beginning with NDB 8.0.17, the  ndb_mgm  client provides a clear acknowledgement that this command has been issued and has taken effect, as shown here: Also in NDB 8.0.17 and later, the API or SQL node having exclusive access when in single user mode is indicated in the output of the  SHOW  command, like this: ndb_mgm>  SHOW Cluster Configuration --------------------- [ndbd(NDB)] 2 node(s) id=5 @127.0.0.1 (mysql-8.0.17 ndb-8.0.17, single user mode, Nodegroup: 0, *) id=6 @127.0.0.1 (mysql-8.0.17 ndb-8.0.17, single user mode, Nodegroup: 0) [ndb_mgmd(MGM)] 1 node(s) ndb_mgm>  ENTER SINGLE USER MODE 100 Single user mode entered Access is granted for API node 100 only. ndb_mgm>  ALL REPORT MEMORY Node 1: Data usage is 5%(177 32K pages of total 3200) Node 1: Index usage is 0%(108 8K pages of total 12832) Node 2: Data usage is 5%(177 32K pages of total 3200) Node 2: Index usage is 0%(108 8K pages of total 12832) • node_id  STATUS • node_id  REPORT  report-type • BackupStatus  provides a status report on a cluster backup in progress • MemoryUsage  displays how much data memory and index memory is being used by each data node as shown in this example: • EventLog  reports events from the event log buffers of one or more data nodes. • ENTER SINGLE USER MODE  node_id 4441