--configinfo

The --configinfo option causes ndb_config to dump a list of each NDB Cluster configuration parameter supported by the NDB Cluster distribution of which ndb_config is a part, including the following information:

By default, this output is in text format. Part of this output is shown here:

shell> ndb_config --configinfo

****** SYSTEM ******

Name (String)
Name of system (NDB Cluster)
MANDATORY

PrimaryMGMNode (Non-negative Integer)
Node id of Primary ndb_mgmd(MGM) node
Default: 0 (Min: 0, Max: 4294967039)

ConfigGenerationNumber (Non-negative Integer)
Configuration generation number
Default: 0 (Min: 0, Max: 4294967039)

****** DB ******

MaxNoOfSubscriptions (Non-negative Integer)
Max no of subscriptions (default 0 == MaxNoOfTables)
Default: 0 (Min: 0, Max: 4294967039)

MaxNoOfSubscribers (Non-negative Integer)
Max no of subscribers (default 0 == 2 * MaxNoOfTables)
Default: 0 (Min: 0, Max: 4294967039)

…

Use this option together with the --xml option to obtain output in XML format.

--config-file=path-to-file

Gives the path to the management server's configuration file (config.ini). This may be a relative or absolute path. If the management node resides on a different host from the one on which ndb_config is invoked, then an absolute path must be used.

--config_from_node=#

Obtain the cluster's configuration data from the data node that has this ID.

If the node having this ID is not a data node, ndb_config fails with an error. (To obtain configuration data from the management node instead, simply omit this option.)

--connections

Tells ndb_config to print CONNECTIONS information only—that is, information about parameters found in the [tcp], [tcp default], [sci], [sci default], [shm], or [shm default] sections of the cluster configuration file (see Section 22.3.3.10, “NDB Cluster TCP/IP Connections”, Section 22.3.3.13, “SCI Transport Connections in NDB Cluster”, and Section 22.3.3.12, “NDB Cluster Shared-Memory Connections”, for more information).

This option is mutually exclusive with --nodes and --system; only one of these 3 options can be used.

--diff-default

Print only configuration parameters that have non-default values.

--fields=delimiter, -f delimiter

Specifies a delimiter string used to separate the fields in the result. The default is , (the comma character).

--host=hostname

Specifies the host name of the node for which configuration information is to be obtained.

--mycnf

Read configuration data from the my.cnf file.

--ndb-connectstring=connection_string, -c connection_string

Specifies the connection string to use in connecting to the management server. The format for the connection string is the same as described in Section 22.3.3.3, “NDB Cluster Connection Strings”, and defaults to localhost:1186.

--nodeid=node_id

Specify the node ID of the node for which configuration information is to be obtained.

--nodes

Tells ndb_config to print information relating only to parameters defined in an [ndbd] or [ndbd default] section of the cluster configuration file (see Section 22.3.3.6, “Defining NDB Cluster Data Nodes”).

This option is mutually exclusive with --connections and --system; only one of these 3 options can be used.

--query=query-options, -q query-options

This is a comma-delimited list of query options—that is, a list of one or more node attributes to be returned. These include nodeid (node ID), type (node type—that is, ndbd, mysqld, or ndb_mgmd), and any configuration parameters whose values are to be obtained.

For example, --query=nodeid,type,datamemory,datadir returns the node ID, node type, DataMemory, and DataDir for each node.

--query-all, -a

Returns a comma-delimited list of all query options (node attributes; note that this list is a single string.

--rows=separator, -r separator

Specifies a separator string used to separate the rows in the result. The default is a space character.

--system

Tells ndb_config to print SYSTEM information only. This consists of system variables that cannot be changed at run time; thus, there is no corresponding section of the cluster configuration file for them. They can be seen (prefixed with ****** SYSTEM ******) in the output of ndb_config --configinfo.

This option is mutually exclusive with --nodes and --connections; only one of these 3 options can be used.

--type=node_type

Filters results so that only configuration values applying to nodes of the specified node_type (ndbd, mysqld, or ndb_mgmd) are returned.

--usage, --help, or -?

Causes ndb_config to print a list of available options, and then exit.

--version, -V

Causes ndb_config to print a version information string, and then exit.

--configinfo --xml

Cause ndb_config --configinfo to provide output as XML by adding this option. A portion of such output is shown in this example:

shell> ndb_config --configinfo --xml

<configvariables protocolversion="1" ndbversionstring="5.7.27-ndb-7.5.16"
                    ndbversion="460032" ndbversionmajor="7" ndbversionminor="5"
                    ndbversionbuild="0">
  <section name="SYSTEM">
    <param name="Name" comment="Name of system (NDB Cluster)" type="string"
              mandatory="true"/>
    <param name="PrimaryMGMNode" comment="Node id of Primary ndb_mgmd(MGM) node"
              type="unsigned" default="0" min="0" max="4294967039"/>
    <param name="ConfigGenerationNumber" comment="Configuration generation number"
              type="unsigned" default="0" min="0" max="4294967039"/>
  </section>
  <section name="MYSQLD" primarykeys="NodeId">
    <param name="wan" comment="Use WAN TCP setting as default" type="bool"
              default="false"/>
    <param name="HostName" comment="Name of computer for this node"
              type="string" default=""/>
    <param name="Id" comment="NodeId" type="unsigned" mandatory="true"
              min="1" max="255" deprecated="true"/>
    <param name="NodeId" comment="Number identifying application node (mysqld(API))"
              type="unsigned" mandatory="true" min="1" max="255"/>
    <param name="ExecuteOnComputer" comment="HostName" type="string"
              deprecated="true"/>

    …

  </section>

  …

</configvariables>

The XML output also indicates when changing a given parameter requires that data nodes be restarted using the --initial option. This is shown by the presence of an initial="true" attribute in the corresponding <param> element. In addition, the restart type (system or node) is also shown; if a given parameter requires a system restart, this is indicated by the presence of a restart="system" attribute in the corresponding <param> element. For example, changing the value set for the Diskless parameter requires a system initial restart, as shown here (with the restart and initial attributes highlighted for visibility):

<param name="Diskless" comment="Run wo/ disk" type="bool" default="false"
          restart="system" initial="true"/>

Currently, no initial attribute is included in the XML output for <param> elements corresponding to parameters which do not require initial restarts; in other words, initial="false" is the default, and the value false should be assumed if the attribute is not present. Similarly, the default restart type is node (that is, an online or “rolling” restart of the cluster), but the restart attribute is included only if the restart type is system (meaning that all cluster nodes must be shut down at the same time, then restarted).

Deprecated parameters are indicated in the XML output by the deprecated attribute, as shown here:

<param name="NoOfDiskPagesToDiskAfterRestartACC" comment="DiskCheckpointSpeed"
       type="unsigned" default="20" min="1" max="4294967039" deprecated="true"/>

In such cases, the comment refers to one or more parameters that supersede the deprecated parameter. Similarly to initial, the deprecated attribute is indicated only when the parameter is deprecated, with deprecated="true", and does not appear at all for parameters which are not deprecated. (Bug #21127135)

Beginning with NDB 7.5.0, parameters that are required are indicated with mandatory="true", as shown here:

<param name="NodeId"
          comment="Number identifying application node (mysqld(API))"
          type="unsigned" mandatory="true" min="1" max="255"/>

In much the same way that the initial or deprecated attribute is displayed only for a parameter that requires an intial restart or that is deprecated, the mandatory attribute is included only if the given parameter is actually required.

Unlike the options used with this program to obtain current configuration data, --configinfo and --xml use information obtained from the NDB Cluster sources when ndb_config was compiled. For this reason, no connection to a running NDB Cluster or access to a config.ini or my.cnf file is required for these two options.