17.4.5. ndb_mgm — The MySQL 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:

shell> ndb_mgm [host_name
        [port_num]]

For example:

shell> ndb_mgm ndb_mgmd.mysql.com
        1186

The default host name and port number are localhost and 1186, respectively.

The following table includes options that are specific to the MySQL Cluster management client program ndb_mgm. Additional descriptions follow the table. For options common to most MySQL Cluster programs (including ndb_mgm), see Section 17.4.25, "Options Common to MySQL Cluster Programs — Options Common to MySQL Cluster Programs".

Table 17.13. ndb_mgm Options and Variables: MySQL Cluster NDB 7.3

Format Description Added / Removed

Format	Description	Added / Removed
`--try-reconnect=#`, `-t`	Specify number of tries for connecting to ndb_mgmd (0 = infinite)	All MySQL 5.6 based releases
`--execute=name`, `-e`	Execute command and exit	All MySQL 5.6 based releases

--try-reconnect=#,

-t

Specify number of tries for connecting to ndb_mgmd (0 = infinite)

All MySQL 5.6 based releases

--execute=name,

-e

Execute command and exit

All MySQL 5.6 based releases

--execute=command, -e command

Command-Line Format	`--execute=name`
	`-e`

This option can be used to send a command to the MySQL Cluster management client from the system shell. For example, either of the following is equivalent to executing SHOW in the management client:

shell> ndb_mgm -e "SHOW"shell> ndb_mgm --execute="SHOW"

This is analogous to how the --execute or -e option works with the mysql command-line client. See Section 4.2.3.1, "Using Options on the Command Line".

Note

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.

--try-reconnect=number

Command-Line Format	`--try-reconnect=#`
	`-t`
	Permitted Values
	Type	`boolean`
	Default	`TRUE`

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.

Additional information about using ndb_mgm can be found in Section 17.5.2, "Commands in the MySQL Cluster Management Client".