MySQL :: MySQL 5.1 Reference Manual :: 17.4.6 ndb_config — Extract MySQL Cluster Configuration Information

MySQL 5.1 Reference Manual :: 17 MySQL Cluster NDB 6.X/7.X :: 17.4 MySQL Cluster Programs :: 17.4.6 ndb_config — Extract MySQL Cluster Configuration Information

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17.4.6. ndb_config — Extract MySQL Cluster Configuration Information

This tool extracts current configuration information for data nodes, SQL nodes, and API nodes from a cluster management node (and possibly its config.ini file). Beginning with MySQL Cluster NDB 6.3.25 and MySQL Cluster NDB 7.0.6, it can also provide an offline dump (in text or XML format) of all configuration parameters which can be used, along with their default, maximum, and minimum values and other information (see the discussion of the --configinfo and --xml options later in this section).

The following table includes options that are specific to ndb_config. 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 17.12. ndb_config Command Line Options

Format	Description	Introduction
--configinfo	Dumps information about all NDB configuration parameters in text format with default, maximum, and minimum values. Use with --xml to obtain XML output.	5.1.34-ndb-7.0.6
--connections	Print connection information only
--fields=string	Field separator
--host=name	Specify host
--mycnf	Read configuration data from my.cnf file
--nodeid	Get configuration of node with this ID
--nodes	Print node information only
	Short form for --ndb-connectstring	5.1.12
--config-file=path	Set the path to config.ini file
--query=string	One or more query options (attributes)
--rows=string	Row separator
--type=name	Specify node type
--configinfo --xml	Use with --configinfo to obtain a dump of all NDB configuration parameters in XML format with default, maximum, and minimum values.	5.1.34-ndb-7.0.6

--usage, --help, or -?

Command-Line Format --help

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

Command-Line Format -V

Causes ndb_config to print a version information string, and then exit.
--ndb-connectstring=connect_string

Command-Line Format --ndb-connectstring=name

Permitted Values

Type string

Default localhost:1186

Specifies the connectstring to use in connecting to the management server. The format for the connectstring is the same as described in Section 17.3.2.3, “The MySQL Cluster Connectstring”, and defaults to localhost:1186.

The use of -c as a short version for this option is supported for ndb_config beginning with MySQL 5.1.12.
--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.
--query=query-options, -q query-options

Command-Line Format --query=string

Permitted Values

Type string

Default

This is a comma-delimited list of query options — that is, a list of one or more node attributes to be returned. These include id (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=id,type,indexmemory,datamemory would return the node ID, node type, DataMemory, and IndexMemory for each node.

Note

If a given parameter is not applicable to a certain type of node, than an empty string is returned for the corresponding value. See the examples later in this section for more information.
--host=hostname

Command-Line Format --host=name

Permitted Values

Type string

Default

Specifies the host name of the node for which configuration information is to be obtained.
--id=node_id, --nodeid=node_id

Used to specify the node ID of the node for which configuration information is to be obtained.
--nodes

Command-Line Format --nodes

Permitted Values

Type boolean

Default FALSE

(Tells ndb_config to print information from parameters defined in [ndbd] sections only. Currently, using this option has no affect, since these are the only values checked, but it may become possible in future to query parameters set in [tcp] and other sections of cluster configuration files.)
--type=node_type

Command-Line Format --type=name

Permitted Values

Type enumeration

Default

Valid Values ndbd, mysqld, ndb_mgmd

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

Command-Line Format --fields=string

Permitted Values

Type string

Default

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

Note

If the delimiter contains spaces or escapes (such as \n for the linefeed character), then it must be quoted.
--rows=separator, -r separator

Command-Line Format --rows=string

Permitted Values

Type string

Default

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

Note

If the separator contains spaces or escapes (such as \n for the linefeed character), then it must be quoted.
--configinfo

The --configinfo option, added in MySQL Cluster NDB 6.3.25 and MySQL Cluster NDB 7.0.6, causes ndb_config to dump a list of each MySQL Cluster configuration parameter supported by the MySQL Cluster distribution of which ndb_config is a part, including the following information:
- A brief description of each parameter's purpose, effects, and usage
- The section of the config.ini file where the parameter may be used
- The parameter's data type or unit of measurement
- Where applicable, the parameter's default, minimum, and maximum values
- A brief description of the parameter's purpose, effects, and usage
- MySQL Cluster release version and build 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)

…
```
--configinfo --xml

Version Introduced 5.1.34-ndb-7.0.6

Command-Line Format --configinfo --xml

Permitted Values

Type boolean

Default false

You can obtain the output of ndb_config --configinfo as XML by adding the --xml option (like the --configinfo option, available beginning with MySQL Cluster NDB 6.3.25 and MySQL Cluster NDB 7.0.6). A portion of the resulting output is shown in this example:
```
shell> ndb_config --configinfo --xml

<configvariables protocolversion="1" ndbversionstring="mysql-5.1.34 ndb-7.0.6"
                    ndbversion="458758" ndbversionmajor="7" ndbversionminor="0"
                    ndbversionbuild="6">
  <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="NDBD">
    <param name="MaxNoOfSubscriptions" comment="Max no of subscriptions (default 0 == MaxNoOfTables)"
              type="unsigned" default="0" min="0" max="4294967039"/>
    <param name="MaxNoOfSubscribers" comment="Max no of subscribers (default 0 == 2 * MaxNoOfTables)"
              type="unsigned" default="0" min="0" max="4294967039"/>

    …

  </section>

  …

</configvariables>
```
Note

Normally, the XML output produced by ndb_config --configinfo --xml is formatted using one line per element; we have added extra whitespace in the previous example, as well as the next one, for reasons of legibility. This should not make any difference to applications using this output, since most XML processors either ignore nonessential whitespace as a matter of course, or can be instructed to do so.

Beginning with MySQL Cluster NDB 6.3.29 and MySQL Cluster NDB 7.0.10, the XML output also indicates when changing a given parameter requires that 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 (also beginning with MySQL Cluster NDB 6.3.29 and MySQL Cluster NDB 7.0.10), 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, 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).

Important

The --xml option can be used only with the --configinfo option. Using --xml without --configinfo fails with an error.

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

Combining other ndb_config options (such as --query or --type) with --configinfo or --xml is not supported. If you attempt to do so, the usual (current) result is that all other options besides --configinfo or --xml are simply ignored. However, this behavior is not guaranteed and is subject to change at any time. In addition, since ndb_config when used with the --configinfo option does not access the MySQL Cluster or read any files, trying to specify additional options such as --ndb-connectstring or --config-file with --configinfo serves no purpose.

Examples:

To obtain the node ID and type of each node in the cluster:
```
shell> ./ndb_config --query=id,type --fields=':' --rows='\n'
1:ndbd
2:ndbd
3:ndbd
4:ndbd
5:ndb_mgmd
6:mysqld
7:mysqld
8:mysqld
9:mysqld
```
In this example, we used the --fields options to separate the ID and type of each node with a colon character (:), and the --rows options to place the values for each node on a new line in the output.

To produce a connectstring that can be used by data, SQL, and API nodes to connect to the management server:

shell> ./ndb_config --config-file=usr/local/mysql/cluster-data/config.ini --query=hostname,portnumber --fields=: --rows=, --type=ndb_mgmd
192.168.0.179:1186

This invocation of ndb_config checks only data nodes (using the --type option), and shows the values for each node's ID and host name, and its DataMemory, IndexMemory, and DataDir parameters:

shell> ./ndb_config --type=ndbd --query=id,host,datamemory,indexmemory,datadir -f ' : ' -r '\n'
1 : 192.168.0.193 : 83886080 : 18874368 : /usr/local/mysql/cluster-data
2 : 192.168.0.112 : 83886080 : 18874368 : /usr/local/mysql/cluster-data
3 : 192.168.0.176 : 83886080 : 18874368 : /usr/local/mysql/cluster-data
4 : 192.168.0.119 : 83886080 : 18874368 : /usr/local/mysql/cluster-data

In this example, we used the short options -f and -r for setting the field delimiter and row separator, respectively.

To exclude results from any host except one in particular, use the --host option:
```
shell> ./ndb_config --host=192.168.0.176 -f : -r '\n' -q id,type
3:ndbd
5:ndb_mgmd
```
In this example, we also used the short form -q to determine the attributes to be queried.

Similarly, you can limit results to a node with a specific ID using the --id or --nodeid option.

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Command-Line Format	`--ndb-connectstring=name`
	Permitted Values
	Type	`string`
	Default	`localhost:1186`

Command-Line Format	`--query=string`
	Permitted Values
	Type	`string`
	Default

Command-Line Format	`--host=name`
	Permitted Values
	Type	`string`
	Default

Command-Line Format	`--nodes`
	Permitted Values
	Type	`boolean`
	Default	`FALSE`

17.4.6. ndb_config — Extract MySQL Cluster Configuration Information

Note

Note

Note

Note

Important

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