This tool extracts current configuration information for data
nodes, SQL nodes, and API nodes from one of a number of sources:
an NDB Cluster management node, or its
config.ini
or my.cnf
file. By default, the management node is the source for the
configuration data; to override the default, execute ndb_config
with the --config-file
or
--mycnf
option. It is also
possible to use a data node as the source by specifying its node
ID with
--config_from_node=
.
node_id
ndb_config can also provide an offline dump
of all configuration parameters which can be used, along with
their default, maximum, and minimum values and other
information. The dump can be produced in either text or XML
format; for more information, see the discussion of the
--configinfo
and
--xml
options later in this
section).
You can filter the results by section (DB
,
SYSTEM
, or CONNECTIONS
)
using one of the options
--nodes
,
--system
, or
--connections
.
All options that can be used with ndb_config are shown in the following table. Additional descriptions follow the table.
-
Command-Line Format --character-sets-dir=path
Directory containing character sets.
-
Command-Line Format --cluster-config-suffix=name
Type String Default Value [none]
Override defaults group suffix when reading cluster configuration sections in
my.cnf
; used in testing. 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:A brief description of each parameter's purpose, effects, and usage
The section of the
config.ini
file where the parameter may be usedThe parameter's data type or unit of measurement
Where applicable, the parameter's default, minimum, and maximum values
NDB Cluster release version and build information
By default, this output is in text format. Part of this output is shown here:
$> ndb_config --configinfo ****** SYSTEM ****** Name (String) Name of system (NDB Cluster) MANDATORY PrimaryMGMNode (Non-negative Integer) Node id of Primary ndb_mgmd(MGM) node Default: 0 (Min: 0, Max: 4294967039) ConfigGenerationNumber (Non-negative Integer) Configuration generation number Default: 0 (Min: 0, Max: 4294967039) ****** DB ****** MaxNoOfSubscriptions (Non-negative Integer) Max no of subscriptions (default 0 == MaxNoOfTables) Default: 0 (Min: 0, Max: 4294967039) MaxNoOfSubscribers (Non-negative Integer) Max no of subscribers (default 0 == 2 * MaxNoOfTables) Default: 0 (Min: 0, Max: 4294967039) …
Use this option together with the
--xml
option to obtain output in XML format.--config-binary-file=
path-to-file
Command-Line Format --config-binary-file=path/to/file
Type File name Default Value Gives the path to the management server's cached binary configuration file (
ndb_
). This may be a relative or absolute path. If the management server and the ndb_config binary used reside on different hosts, you must use an absolute path.nodeID
_config.bin.seqno
This example demonstrates combining
--config-binary-file
with other ndb_config options to obtain useful output:$> ndb_config --config-binary-file=../mysql-cluster/ndb_50_config.bin.1 --diff-default --type=ndbd config of [DB] node id 5 that is different from default CONFIG_PARAMETER,ACTUAL_VALUE,DEFAULT_VALUE NodeId,5,(mandatory) BackupDataDir,/local/data/8.4,(null) DataDir,/local/data/8.4,. DataMemory,2G,98M FileSystemPath,/local/data/8.4,(null) HostName,127.0.0.1,localhost Nodegroup,0,(null) ThreadConfig,,(null) config of [DB] node id 6 that is different from default CONFIG_PARAMETER,ACTUAL_VALUE,DEFAULT_VALUE NodeId,6,(mandatory) BackupDataDir,/local/data/8.4,(null) DataDir,/local/data/8.4. DataMemory,2G,98M FileSystemPath,/local/data/8.4,(null) HostName,127.0.0.1,localhost Nodegroup,0,(null) ThreadConfig,,(null) $> ndb_config --config-binary-file=../mysql-cluster/ndb_50_config.bin.1 --diff-default --system config of [SYSTEM] system CONFIG_PARAMETER,ACTUAL_VALUE,DEFAULT_VALUE Name,MC_20220906060042,(mandatory) ConfigGenerationNumber,1,0 PrimaryMGMNode,50,0
The relevant portions of the
config.ini
file are shown here:[ndbd default] DataMemory= 2G NoOfReplicas= 2 [ndb_mgmd] NodeId= 50 HostName= 127.0.0.1 [ndbd] NodeId= 5 HostName= 127.0.0.1 DataDir= /local/data/8.4 [ndbd] NodeId= 6 HostName= 127.0.0.1 DataDir= /local/data/8.4
By comparing the output with the configuration file, you can see that all of the settings in the file have been written by the management server to the binary cache, and thus, applied to the cluster.
-
Command-Line Format --config-file=file_name
Type File name Default Value Gives the path to the cluster configuration file (
config.ini
). This may be a relative or absolute path. If the management server and the ndb_config binary used reside on different hosts, you must use an absolute path. -
Command-Line Format --config-from-node=#
Type Numeric Default Value none
Minimum Value 1
Maximum Value 48
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.)
-
Command-Line Format --connect-retries=#
Type Integer Default Value 12
Minimum Value 0
Maximum Value 12
Number of times to retry connection before giving up.
-
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.
-
Command-Line Format --connect-string=connection_string
Type String Default Value [none]
Same as
--ndb-connectstring
. -
Command-Line Format --connections
Tells ndb_config to print
CONNECTIONS
information only—that is, information about parameters found in the[tcp]
,[tcp default]
,[shm]
, or[shm default]
sections of the cluster configuration file (see Section 25.4.3.10, “NDB Cluster TCP/IP Connections”, and Section 25.4.3.12, “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. -
Command-Line Format --core-file
Write core file on error; used in debugging.
-
Command-Line Format --defaults-extra-file=path
Type String Default Value [none]
Read given file after global files are read.
-
Command-Line Format --defaults-file=path
Type String Default Value [none]
Read default options from given file only.
-
Command-Line Format --defaults-group-suffix=string
Type String Default Value [none]
Also read groups with concat(group, suffix).
-
Command-Line Format --diff-default
Print only configuration parameters that have non-default values.
--fields=
,delimiter
-f
delimiter
Command-Line Format --fields=string
Type String Default Value Specifies a
delimiter
string used to separate the fields in the result. The default is,
(the comma character).NoteIf the
delimiter
contains spaces or escapes (such as\n
for the linefeed character), then it must be quoted.-
Command-Line Format --help
Display help text and exit.
-
Command-Line Format --host=name
Type String Default Value Specifies the host name of the node for which configuration information is to be obtained.
NoteWhile the hostname
localhost
usually resolves to the IP address127.0.0.1
, this may not necessarily be true for all operating platforms and configurations. This means that it is possible, whenlocalhost
is used inconfig.ini
, for ndb_config--host=localhost
to fail if ndb_config is run on a different host wherelocalhost
resolves to a different address (for example, on some versions of SUSE Linux, this is127.0.0.2
). In general, for best results, you should use numeric IP addresses for all NDB Cluster configuration values relating to hosts, or verify that all NDB Cluster hosts handlelocalhost
in the same fashion. -
Command-Line Format --login-path=path
Type String Default Value [none]
Read given path from login file.
-
Command-Line Format --mycnf
Read configuration data from the
my.cnf
file. --ndb-connectstring=
,connection_string
-c
connection_string
Command-Line Format --ndb-connectstring=connection_string
Type String Default Value [none]
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 25.4.3.3, “NDB Cluster Connection Strings”, and defaults to
localhost:1186
.-
Command-Line Format --ndb-mgm-tls=level
Type Enumeration Default Value relaxed
Valid Values relaxed
strict
Sets the level of TLS support required to connect to the management server; one of
relaxed
orstrict
.relaxed
(the default) means that a TLS connection is attempted, but success is not required;strict
means that TLS is required to connect. -
Command-Line Format --ndb-mgmd-host=connection_string
Type String Default Value [none]
Same as
--ndb-connectstring
. -
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.-
Command-Line Format --ndb-tls-search-path=list
Type Path name Default Value (Unix) $HOME/ndb-tls
Default Value (Windows) $HOMEDIR/ndb-tls
Specify a list of directories to search for a CA file. On Unix platforms, the directory names are separated by colons (
:
); on Windows systems, the semicolon character (;
) is used as the separator. A directory reference may be relative or absolute; it may contain one or more environment variables, each denoted by a prefixed dollar sign ($
), and expanded prior to use.Searching begins with the leftmost named directory and proceeds from left to right until a file is found. An empty string denotes an empty search path, which causes all searches to fail. A string consisting of a single dot (
.
) indicates that the search path limited to the current working directory.If no search path is supplied, the compiled-in default value is used. This value depends on the platform used: On Windows, this is
\ndb-tls
; on other platforms (including Linux), it is$HOME/ndb-tls
. This can be overridden by compiling NDB Cluster using-DWITH_NDB_TLS_SEARCH_PATH
. -
Command-Line Format --no-defaults
Do not read default options from any option file other than login file.
-
Command-Line Format --no-login-paths
Skips reading options from the login path file.
-
Command-Line Format --ndb-nodeid=#
Type Integer Default Value [none]
Specify the node ID of the node for which configuration information is to be obtained.
-
Command-Line Format --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 25.4.3.6, “Defining NDB Cluster Data Nodes”).This option is mutually exclusive with
--connections
and--system
; only one of these 3 options can be used. -
Command-Line Format --print-defaults
Print program argument list and exit.
--query=
,query-options
-q
query-options
Command-Line Format --query=string
Type String Default Value 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
, orndb_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
, andDataDir
for each node.NoteIf 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.
--query-all
,-a
Command-Line Format --query-all
Type String Default Value Returns a comma-delimited list of all query options (node attributes; note that this list is a single string.
--rows=
,separator
-r
separator
Command-Line Format --rows=string
Type String Default Value Specifies a
separator
string used to separate the rows in the result. The default is a space character.NoteIf the
separator
contains spaces or escapes (such as\n
for the linefeed character), then it must be quoted.-
Command-Line Format --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. -
Command-Line Format --type=name
Type Enumeration Default Value [none]
Valid Values ndbd
mysqld
ndb_mgmd
Filters results so that only configuration values applying to nodes of the specified
node_type
(ndbd
,mysqld
, orndb_mgmd
) are returned. --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 --version
Causes ndb_config to print a version information string, and then exit.
--configinfo
--xml
Command-Line Format --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:$> ndb_config --configinfo --xml <configvariables protocolversion="1" ndbversionstring="5.7.44-ndb-7.5.35" 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>
NoteNormally, 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.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 aninitial="true"
attribute in the corresponding<param>
element. In addition, the restart type (system
ornode
) is also shown; if a given parameter requires a system restart, this is indicated by the presence of arestart="system"
attribute in the corresponding<param>
element. For example, changing the value set for theDiskless
parameter requires a system initial restart, as shown here (with therestart
andinitial
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 valuefalse
should be assumed if the attribute is not present. Similarly, the default restart type isnode
(that is, an online or “rolling” restart of the cluster), but therestart
attribute is included only if the restart type issystem
(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 toinitial
, thedeprecated
attribute is indicated only when the parameter is deprecated, withdeprecated="true"
, and does not appear at all for parameters which are not deprecated. (Bug #21127135)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
ordeprecated
attribute is displayed only for a parameter that requires an initial restart or that is deprecated, themandatory
attribute is included only if the given parameter is actually required.ImportantThe
--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 NDB Cluster sources when ndb_config was compiled. For this reason, no connection to a running NDB Cluster or access to aconfig.ini
ormy.cnf
file is required for these two options.
Combining other ndb_config options (such as
--query
or
--type
) with
--configinfo
(with or without the
--xml
option is not supported. Currently, if
you attempt to do so, the usual 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
NDB 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:
$> ./ndb_config --query=nodeid,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 connection string that can be used by data, SQL, and API nodes to connect to the management server:
$> ./ndb_config --config-file=usr/local/mysql/cluster-data/config.ini \ --query=hostname,portnumber --fields=: --rows=, --type=ndb_mgmd 198.51.100.179:1186
This invocation of ndb_config checks only data nodes (using the
--type
option), and shows the values for each node's ID and host name, as well as the values set for itsDataMemory
andDataDir
parameters:$> ./ndb_config --type=ndbd --query=nodeid,host,datamemory,datadir -f ' : ' -r '\n' 1 : 198.51.100.193 : 83886080 : /usr/local/mysql/cluster-data 2 : 198.51.100.112 : 83886080 : /usr/local/mysql/cluster-data 3 : 198.51.100.176 : 83886080 : /usr/local/mysql/cluster-data 4 : 198.51.100.119 : 83886080 : /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, as well as the short option-q
to pass a list of parameters to be obtained.To exclude results from any host except one in particular, use the
--host
option:$> ./ndb_config --host=198.51.100.176 -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
--nodeid
option.