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MySQL 5.7 Reference Manual  /  ...  /  ndb_mgm — The NDB Cluster Management Client

21.5.5 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]]

For example:

$> ndb_mgm ndb_mgmd.mysql.com 1186

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

Options that can be used with ndb_mgm are shown in the following table. Additional descriptions follow the table.

Table 21.25 Command-line options used with the program ndb_mgm

Format Description Added, Deprecated, or Removed

--character-sets-dir=path

Directory containing character sets

(Supported in all NDB releases based on MySQL 5.7)

--connect-retry-delay=#

Number of seconds to wait between attempts to contact management server

(Supported in all NDB releases based on MySQL 5.7)

--connect-string=connection_string,

-c connection_string

Same as --ndb-connectstring

(Supported in all NDB releases based on MySQL 5.7)

--core-file

Write core file on error; used in debugging

(Supported in all NDB releases based on MySQL 5.7)

--defaults-extra-file=path

Read given file after global files are read

(Supported in all NDB releases based on MySQL 5.7)

--defaults-file=path

Read default options from given file only

(Supported in all NDB releases based on MySQL 5.7)

--defaults-group-suffix=string

Also read groups with concat(group, suffix)

(Supported in all NDB releases based on MySQL 5.7)

--execute=command,

-e command

Execute command and exit

(Supported in all NDB releases based on MySQL 5.7)

--help,

-?

Display help text and exit

(Supported in all NDB releases based on MySQL 5.7)

--login-path=path

Read given path from login file

(Supported in all NDB releases based on MySQL 5.7)

--ndb-connectstring=connection_string,

-c connection_string

Set connect string for connecting to ndb_mgmd. Syntax: "[nodeid=id;][host=]hostname[:port]". Overrides entries in NDB_CONNECTSTRING and my.cnf

(Supported in all NDB releases based on MySQL 5.7)

--ndb-mgmd-host=connection_string,

-c connection_string

Same as --ndb-connectstring

(Supported in all NDB releases based on MySQL 5.7)

--ndb-nodeid=#

Set node ID for this node, overriding any ID set by --ndb-connectstring

(Supported in all NDB releases based on MySQL 5.7)

--ndb-optimized-node-selection

Enable optimizations for selection of nodes for transactions. Enabled by default; use --skip-ndb-optimized-node-selection to disable

(Supported in all NDB releases based on MySQL 5.7)

--no-defaults

Do not read default options from any option file other than login file

(Supported in all NDB releases based on MySQL 5.7)

--print-defaults

Print program argument list and exit

(Supported in all NDB releases based on MySQL 5.7)

--try-reconnect=#,

-t #

Set number of times to retry connection before giving up; synonym for --connect-retries

(Supported in all NDB releases based on MySQL 5.7)

--usage,

-?

Display help text and exit; same as --help

(Supported in all NDB releases based on MySQL 5.7)

--version,

-V

Display version information and exit

(Supported in all NDB releases based on MySQL 5.7)


  • --character-sets-dir

    Command-Line Format --character-sets-dir=path

    Directory containing character sets.

  • --connect-retries=#

    Command-Line Format --connect-retries=#
    Type Numeric
    Default Value 3
    Minimum Value 0
    Maximum Value 4294967295

    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.

  • --connect-retry-delay

    Command-Line Format --connect-retry-delay=#
    Type Integer
    Default Value 5
    Minimum Value 0
    Maximum Value 5

    Number of seconds to wait between attempts to contact management server.

  • --connect-string

    Command-Line Format --connect-string=connection_string
    Type String
    Default Value [none]

    Same as --ndb-connectstring.

  • --core-file

    Command-Line Format --core-file

    Write core file on error; used in debugging.

  • --defaults-extra-file

    Command-Line Format --defaults-extra-file=path
    Type String
    Default Value [none]

    Read given file after global files are read.

  • --defaults-file

    Command-Line Format --defaults-file=path
    Type String
    Default Value [none]

    Read default options from given file only.

  • --defaults-group-suffix

    Command-Line Format --defaults-group-suffix=string
    Type String
    Default Value [none]

    Also read groups with concat(group, suffix).

  • --execute=command, -e command

    Command-Line Format --execute=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 4.2.2.1, “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.

  • --help

    Command-Line Format --help

    Display help text and exit.

  • --login-path

    Command-Line Format --login-path=path
    Type String
    Default Value [none]

    Read given path from login file.

  • --ndb-connectstring

    Command-Line Format --ndb-connectstring=connection_string
    Type String
    Default Value [none]

    Set connect string for connecting to ndb_mgmd. Syntax: [nodeid=id;][host=]hostname[:port]. Overrides entries in NDB_CONNECTSTRING and my.cnf.

  • --ndb-mgmd-host

    Command-Line Format --ndb-mgmd-host=connection_string
    Type String
    Default Value [none]

    Same as --ndb-connectstring.

  • --ndb-nodeid

    Command-Line Format --ndb-nodeid=#
    Type Integer
    Default Value [none]

    Set node ID for this node, overriding any ID set by --ndb-connectstring.

  • --ndb-optimized-node-selection

    Command-Line Format --ndb-optimized-node-selection

    Enable optimizations for selection of nodes for transactions. Enabled by default; use --skip-ndb-optimized-node-selection to disable.

  • --no-defaults

    Command-Line Format --no-defaults

    Do not read default options from any option file other than login file.

  • --print-defaults

    Command-Line Format --print-defaults

    Print program argument list and exit.

  • --try-reconnect=number

    Command-Line Format --try-reconnect=#
    Deprecated Yes
    Type (≥ 5.7.10-ndb-7.5.0) Numeric
    Type Integer
    Default Value (≥ 5.7.10-ndb-7.5.0) 12
    Default Value 3
    Minimum Value 0
    Maximum Value 4294967295

    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.

  • --usage

    Command-Line Format --usage

    Display help text and exit; same as --help.

  • --version

    Command-Line Format --version

    Display version information and exit.

Additional information about using ndb_mgm can be found in Section 21.6.1, “Commands in the NDB Cluster Management Client”.