MySQL Reference Manual :: 16.4.4.1 Example Configuration for a MySQL Cluster

In order to support MySQL Cluster, you will need to update my.cnf as shown in the example below.

From version 4.1.8 some simplifications in my.cnf were made, including new sections for ndbcluster executables. However, these should not be confused with those occurring in config.ini files. As always, you may specify these parameters when invoking those executables from the command line.

# my.cnf
# example additions to my.cnf for MySQL Cluster
# (valid from 4.1.8)

# enable ndbcluster storage engine, and provide connectstring for
# management server host (default port is 1186)
[mysqld]
ndbcluster
ndb-connectstring=ndb_mgmd.mysql.com


# provide connectstring for management server host (default port: 1186)
[ndbd]
connect-string=ndb_mgmd.mysql.com

# provide connectstring for management server host (default port: 1186)
[ndb_mgm]
connect-string=ndb_mgmd.mysql.com

# provide location of cluster configuration file
[ndb_mgmd]
config-file=/etc/config.ini

(For more information on connectstrings, see Section 16.4.4.2, “The MySQL Cluster connectstring”.)

# my.cnf
# example additions to my.cnf for MySQL Cluster
# (will work on all versions)

# enable ndbcluster storage engine, and provide connectstring for management
# server host to the default port 1186
[mysqld]
ndbcluster
ndb-connectstring=ndb_mgmd.mysql.com:1186

Also starting with MySQL 4.1.8, the my.cnf file supports a separate [mysql_cluster] section for settings to be read by and affecting all executables in the cluster:

# cluster-specific settings
[mysql_cluster]
ndb-connectstring=ndb_mgmd.mysql.com:1186

Currently the configuration file is in INI format, and is named config.ini by default. It is read by ndb_mgmd at startup and can be placed anywhere. Its location and name are specified by using --config-file=[<path>]<filename> on the command line with ndb_mgmd. If the configuration file is not specified, ndb_mgmd will by default try to read a config.ini file located in the current working directory.

Default values are defined for most parameters, and can also be specified in config.ini. To create a default value section, simply add the word DEFAULT to the section name. For example, data nodes are configured using [NDBD] sections. If all data nodes use the same data memory size, and this is not the same as the default size, create an [NDBD DEFAULT] section containing a DataMemory line to specify the default data memory size for all data nodes.

The INI format consists of sections preceded by section headings (surrounded by square brackets), followed by the appropriate parameter names and values. One deviation from the standard format is that the parameter name and value can be separated by a colon (':') as well as the equals sign ('='); another is that sections are not uniquely identified by name. Instead, unique entries (such as two different nodes of the same type) are identified by a unique ID.

At a minimum, the configuration file must define the computers and nodes involved in the cluster and on which computers these nodes are located. An example of a simple configuration file for a cluster consisting of one management server, two data nodes and two MySQL servers is shown below:

# file "config.ini" - 2 data nodes and 2 SQL nodes
# This file is placed in the startup directory of ndb_mgmd (the management
# server)
# The first MySQL Server can be started from any host. The second can be started
# only on the host mysqld_5.mysql.com

[NDBD DEFAULT]
NoOfReplicas= 2
DataDir= /var/lib/mysql-cluster

[NDB_MGMD]
Hostname= ndb_mgmd.mysql.com
DataDir= /var/lib/mysql-cluster

[NDBD]
HostName= ndbd_2.mysql.com

[NDBD]
HostName= ndbd_3.mysql.com

[MYSQLD]
[MYSQLD]
HostName= mysqld_5.mysql.com

There are six different sections in this configuration file:

Note that each node has its own section in the config.ini. For instance, since this cluster has two data nodes, the configuration file contains two sections defining these nodes.

One can define DEFAULT values for each section. As of MySQL 4.1.5, all parameter names are case-insensitive.