ndb_mgm − the NDB Cluster management client
The ndb_mgm management client process is actually not needed to run the cluster. Its value lies in providing a set of commands for checking the cluster's status, starting backups, and performing other administrative functions. The management client accesses the management server using a C API. Advanced users can also employ this API for programming dedicated management processes to perform tasks similar to those performed by ndb_mgm.
To start the management client, it is necessary to supply the host name and port number of the management server:
$> ndb_mgm [host_name [port_num]]
$> ndb_mgm ndb_mgmd.mysql.com 1186
The default host name and port number are localhost and 1186, respectively.
All options that can be used with ndb_mgm are shown in the following table. Additional descriptions follow the table.
Table 23.27. Command−line options used with the program ndb_mgm
This option enables input of the backup password from the system shell (stdin) when using −−execute "START BACKUP" or similar to create a backup. Use of this option requires use of −−execute as well.
Directory containing character sets.
This option specifies the number of times following the first attempt to retry a connection before giving up (the client always tries the connection at least once). The length of time to wait per attempt is set using −−connect−retry−delay.
This option is synonymous with the −−try−reconnect option, which is now deprecated.
Number of seconds to wait between attempts to contact management server.
Same as −−ndb−connectstring.
Write core file on error; used in debugging.
Read given file after global files are read.
Read default options from given file only.
Also read groups with concat(group, suffix).
When used, this option causes all backups to be encrypted. To make this happen whenever ndb_mgm is run, put the option in the [ndb_mgm] section of the my.cnf file.
• −−execute=command, −e command
This option can be used to send a command to the NDB Cluster management client from the system shell. For example, either of the following is equivalent to executing SHOW in the management client:
ndb_mgm −e "SHOW"
$> ndb_mgm −−execute="SHOW"
This is analogous to how the −−execute or −e option works with the mysql command−line client. See Section 126.96.36.199, “Using Options on the Command Line”.
If the management client command to be passed using this option contains any space characters, then the command must be enclosed in quotation marks. Either single or double quotation marks may be used. If the management client command contains no space characters, the quotation marks are optional.
Display help text and exit.
Read given path from login file.
Set connect string for connecting to ndb_mgmd. Syntax: [nodeid=id;][host=]hostname[:port]. Overrides entries in NDB_CONNECTSTRING and my.cnf.
Set node ID for this node, overriding any ID set by −−ndb−connectstring.
Same as −−ndb−connectstring.
Enable optimizations for selection of nodes for transactions. Enabled by default; use −−skip−ndb−optimized−node−selection to disable.
Do not read default options from any option file other than login file.
Print program argument list and exit.
If the connection to the management server is broken, the node tries to reconnect to it every 5 seconds until it succeeds. By using this option, it is possible to limit the number of attempts to number before giving up and reporting an error instead.
This option is deprecated and subject to removal in a future release. Use −−connect−retries, instead.
Display help text and exit; same as −−help.
Display version information and exit.
Additional information about using ndb_mgm can be found in Section 23.6.1, “Commands in the NDB Cluster Management Client”.
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