Management of NDB Cluster • --usage ,  -? • --version ,  -V Synonym for  --help . Prints out version information. ndbxfrm  can encrypt backups created by any version of NDB Cluster. The  .Data ,  .ctl , and  .log  files comprising the backup must be encrypted separately, and these files must be encrypted separately for each data node. Once encrypted, such backups can be decrypted only by  ndbxfrm ,  ndb_restore , or ndb_print_backup  from NDB Cluster 8.0.22 or later. An encrypted file can be re-encrypted with a new password using the  --encrypt-password  and  -- decrypt-password  options together, like this: ndbxfrm --decrypt-password= old  --encrypt-password= new input_file output_file In the example just shown,  old  and  new  are the old and new passwords, respectively; both of these must be quoted. The input file is decrypted and then encrypted as the output file. The input file itself is not changed; if you do not want it to be accessible using the old password, you must remove the input file manually. 23.5 Management of NDB Cluster Managing an NDB Cluster involves a number of tasks, the first of which is to configure and start NDB Cluster. This is covered in Section 23.3, “Configuration of NDB Cluster” , and Section 23.4, “NDB Cluster Programs” . The next few sections cover the management of a running NDB Cluster. For information about security issues relating to management and deployment of an NDB Cluster, see Section 23.5.17, “NDB Cluster Security Issues” . There are essentially two methods of actively managing a running NDB Cluster. The first of these is through the use of commands entered into the management client whereby cluster status can be checked, log levels changed, backups started and stopped, and nodes stopped and started. The second method involves studying the contents of the cluster log  ndb_ node_id _cluster.log ; this is usually found in the management server’s  DataDir  directory, but this location can be overridden using the  LogDestination option. (Recall that  node_id  represents the unique identifier of the node whose activity is being logged.) The cluster log contains event reports generated by  ndbd . It is also possible to send cluster log entries to a Unix system log. Some aspects of the cluster’s operation can be also be monitored from an SQL node using the  SHOW ENGINE NDB STATUS  statement. More detailed information about NDB Cluster operations is available in real time through an SQL interface using the  ndbinfo  database. For more information, see Section 23.5.14, “ndbinfo: The NDB Cluster Information Database” . NDB statistics counters provide improved monitoring using the  mysql  client. These counters, implemented in the NDB kernel, relate to operations performed by or affecting  Ndb  objects, such as starting, closing, and aborting transactions; primary key and unique key operations; table, range, and pruned scans; blocked threads waiting for various operations to complete; and data and events sent and received by NDB Cluster. The counters are incremented by the NDB kernel whenever NDB API calls are made or data is sent to or received by the data nodes. 4438