MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6

21.4.4 ndb_mgmd — The NDB Cluster Management Server Daemon

The management server is the process that reads the cluster configuration file and distributes this information to all nodes in the cluster that request it. It also maintains a log of cluster activities. Management clients can connect to the management server and check the cluster's status.

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

Table 21.24 Command-line options used with the program ndb_mgmd

Format Description Added, Deprecated, or Removed

--bind-address=host

Local bind address

(Supported in all NDB releases based on MySQL 5.7)

--character-sets-dir=path

Directory containing character sets

(Supported in all NDB releases based on MySQL 5.7)

--config-cache[=TRUE|FALSE]

Enable management server configuration cache; true by default

(Supported in all NDB releases based on MySQL 5.7)

--config-file=file,

-f

Specify cluster configuration file; also specify --reload or --initial to override configuration cache if present

(Supported in all NDB releases based on MySQL 5.7)

--configdir=directory,

--config-dir=directory

Specify cluster management server configuration cache directory

(Supported in all NDB releases based on MySQL 5.7)

--connect-retries=#

Number of times to retry connection before giving up

(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

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)

--daemon,

-d

Run ndb_mgmd in daemon mode (default)

(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)

--help,

-?

Display help text and exit

(Supported in all NDB releases based on MySQL 5.7)

--initial

Causes management server to reload configuration data from configuration file, bypassing configuration cache

(Supported in all NDB releases based on MySQL 5.7)

--install[=name]

Used to install management server process as Windows service; does not apply on other platforms

(Supported in all NDB releases based on MySQL 5.7)

--interactive

Run ndb_mgmd in interactive mode (not officially supported in production; for testing purposes only)

(Supported in all NDB releases based on MySQL 5.7)

--log-name=name

Name to use when writing cluster log messages applying to this node

(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)

--mycnf

Read cluster configuration data from my.cnf file

(Supported in all NDB releases based on MySQL 5.7)

--ndb-connectstring=connection-string,

-c

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

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)

--no-nodeid-checks

Do not provide any node ID checks

(Supported in all NDB releases based on MySQL 5.7)

--nodaemon

Do not run ndb_mgmd as a daemon

(Supported in all NDB releases based on MySQL 5.7)

--nowait-nodes=list

Do not wait for management nodes specified when starting this management server; requires --ndb-nodeid option

(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)

--print-full-config,

-P

Print full configuration and exit

(Supported in all NDB releases based on MySQL 5.7)

--reload

Causes management server to compare configuration file with configuration cache

(Supported in all NDB releases based on MySQL 5.7)

--remove[=name]

Used to remove management server process that was previously installed as Windows service, optionally specifying name of service to be removed; does not apply on other platforms

(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)

--skip-config-file

Do not use configuration file

(Supported in all NDB releases based on MySQL 5.7)

--verbose,

-v

Write additional information to log

(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)


It is not strictly necessary to specify a connection string when starting the management server. However, if you are using more than one management server, a connection string should be provided and each node in the cluster should specify its node ID explicitly.

See Section 21.3.3.3, “NDB Cluster Connection Strings”, for information about using connection strings. Section 21.4.4, “ndb_mgmd — The NDB Cluster Management Server Daemon”, describes other options for ndb_mgmd.

The following files are created or used by ndb_mgmd in its starting directory, and are placed in the DataDir as specified in the config.ini configuration file. In the list that follows, node_id is the unique node identifier.