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MySQL 5.1 Reference Manual :: 17 MySQL Cluster NDB 6.X/7.X :: 17.4 MySQL Cluster Programs :: 17.4.4 ndb_mgmd — The MySQL Cluster Management Server Daemon
17.4.5 ndb_mgm — The MySQL Cluster Management Client »
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17.4.4. ndb_mgmd — The MySQL 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.

The following table includes options that are specific to the MySQL Cluster management server program ndb_mgmd. Additional descriptions follow the table. For options common to all MySQL Cluster programs, see Section 17.4.23, “Options Common to MySQL Cluster Programs”.

Table 17.10. ndb_mgmd Command Line Options

Format Description Introduction Deprecated Removed
--bind-address Local bind address 5.1.22-ndb-6.3.2    
-c Specify the cluster configuration file; in NDB-6.4.0 and later, needs --reload or --initial to override configuration cache if present      
--configdir=directory Specify the cluster management server's configuration cache directory 5.1.30-ndb-6.4.0    
--daemon Run ndb_mgmd in daemon mode (default)      
--initial Causes the management server reload its configuration data from the configuration file, bypassing the configuration cache 5.1.30-ndb-6.4.0    
--interactive Run ndb_mgmd in interactive mode (not officially supported in production; for testing purposes only)      
--log-name= A name to use when writing messages applying to this node in the cluster log. 5.1.37-ndb-7.0.8    
--mycnf Read cluster configuration data from the my.cnf file      
--no-nodeid-checks Do not provide any node id checks      
--nodaemon Do not run ndb_mgmd as a daemon      
--print-full-config Print full configuration and exit      
--reload Causes the management server to compare the configuration file with its configuration cache 5.1.30-ndb-6.4.0    

  • --bind-address=host[:port]

    Version Introduced 5.1.22-ndb-6.3.2
    Command Line Format --bind-address
      Permitted Values
    Type string
    Default [none]

    When specified, this option limits management server connections by management clients to clients at the specified host name or IP address (and possibly port, if this is also specified). In such cases, a management client attempting to connect to the management server from any other address fails with the error Unable to setup port: host:port!

    If the port is not specified, the management client attempts to use port 1186.

    This option was added in MySQL Cluster NDB 6.2.5 and MySQL Cluster NDB 6.3.2.

  • --configdir=directory

    Version Introduced 5.1.30-ndb-6.4.0
    Command Line Format --configdir=directory
      Permitted Values
    Type filename
    Default $INSTALLDIR/mysql-cluster

    Beginning with MySQL Cluster NDB 6.4.0, configuration data is cached internally rather than being read from the cluster global configuration file each time the management server is started (see Section 17.3.2, “MySQL Cluster Configuration Files”). This option instructs the management server to its configuration cache in the directory indicated. By default, this is a directory named mysql-cluster in the MySQL installation directory — for example, if you compile and install MySQL Cluster on a Unix system using the default location, this is /usr/local/mysql-cluster.

    This behavior can be overridden using the --initial or --reload option for ndb_mgmd. Each of these options is described elsewhere in this section.

    This option is available beginning with MySQL Cluster NDB 6.4.0.

    Beginning with MySQL Cluster NDB 7.0.8, --config-dir is accepted as an alias for --configdir.

  • --config-file=filename, -f filename

    Command Line Format -c
      Permitted Values
    Type filename
    Default ./config.ini

    Instructs the management server as to which file it should use for its configuration file. By default, the management server looks for a file named config.ini in the same directory as the ndb_mgmd executable; otherwise the file name and location must be specified explicitly.

    Beginning with MySQL Cluster NDB 6.4.0, this option is ignored unless the management server is forced to read the configuration file, either because ndb_mgmd was started with the --reload or --initial option, or because the management server could not find any configuration cache. See Section 17.3.2, “MySQL Cluster Configuration Files”, for more information.

  • --daemon, -d

    Command Line Format --daemon
      Permitted Values
    Type boolean
    Default TRUE

    Instructs ndb_mgmd to start as a daemon process. This is the default behavior.

    This option has no effect when running ndb_mgmd on Windows platforms.

  • --initial

    Version Introduced 5.1.30-ndb-6.4.0
    Command Line Format --initial
      Permitted Values
    Type boolean
    Default FALSE

    Beginning with MySQL Cluster NDB 6.4.0, configuration data is cached internally rather than being read from the cluster global configuration file each time the management server is started (see Section 17.3.2, “MySQL Cluster Configuration Files”). Using this option overrides this behavior, by forcing the management server to delete any existing cache files, and then to re-read the configuration data from the cluster configuration file and to build a new cache.

    This differs in two ways from the --reload option. First, --reload forces the server to check the configuration file against the cache and reload its data only if the contents of the file are different from the cache. Second, --reload does not delete any existing cache files.

    If ndb_mgmd is invoked with --initial but cannot find a global configuration file, the management server cannot start.

    This option was introduced in MySQL Cluster NDB 6.4.0.

  • --log-name=name

    Version Introduced 5.1.37-ndb-7.0.8
    Command Line Format --log-name=
      Permitted Values
    Type string
    Default MgmtSrvr

    Provides a name to be used for this node in the cluster log.

    This option was added in MySQL Cluster NDB 7.0.8.

  • --nodaemon

    Command Line Format --nodaemon
      Permitted Values
    Type boolean
    Default FALSE

    Instructs ndb_mgmd not to start as a daemon process.

    As of MySQL Cluster NDB 7.0.8, the default behavior for ndb_mgmd on Windows is to run in the foreground, making this option unnecessary on Windows platforms. (Bug#45588)

  • --print-full-config, -P

    Command Line Format --print-full-config
      Permitted Values
    Type boolean
    Default FALSE

    Shows extended information regarding the configuration of the cluster. With this option on the command line the ndb_mgmd process prints information about the cluster setup including an extensive list of the cluster configuration sections as well as parameters and their values. Normally used together with the --config-file (-f) option.

  • --reload

    Version Introduced 5.1.30-ndb-6.4.0
    Command Line Format --reload
      Permitted Values
    Type boolean
    Default FALSE

    Beginning with MySQL Cluster NDB 6.4.0, configuration data is stored internally rather than being read from the cluster global configuration file each time the management server is started (see Section 17.3.2, “MySQL Cluster Configuration Files”). Using this option forces the management server to check its internal data store against the cluster configuration file and to reload the configuration if it finds that the configuration file does not match the cache. Existing configuration cache files are preserved, but not used.

    This differs in two ways from the --initial option. First, --initial causes all cache files to be deleted. Second, --initial forces the management server to re-read the global configuration file and construct a new cache.

    If the management server cannot find a global configuration file, then the --reload option is ignored.

    This option was introduced in MySQL Cluster NDB 6.4.0.

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

See Section 17.3.2.3, “The MySQL Cluster Connectstring”, for information about using connectstrings. Section 17.4.4, “ndb_mgmd — The MySQL 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.

  • config.ini is the configuration file for the cluster as a whole. This file is created by the user and read by the management server. Section 17.3, “MySQL Cluster Configuration”, discusses how to set up this file.

  • ndb_node_id_cluster.log is the cluster events log file. Examples of such events include checkpoint startup and completion, node startup events, node failures, and levels of memory usage. A complete listing of cluster events with descriptions may be found in Section 17.5, “Management of MySQL Cluster”.

    When the size of the cluster log reaches one million bytes, the file is renamed to ndb_node_id_cluster.log.seq_id, where seq_id is the sequence number of the cluster log file. (For example: If files with the sequence numbers 1, 2, and 3 already exist, the next log file is named using the number 4.)

  • ndb_node_id_out.log is the file used for stdout and stderr when running the management server as a daemon.

  • ndb_node_id.pid is the process ID file used when running the management server as a daemon.