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MySQL 5.1 Reference Manual :: 20 MySQL Cluster :: 20.4 MySQL Cluster Options and Variables :: 20.4.2 MySQL Cluster-Related Command Options for mysqld
20.4.3 MySQL Cluster System Variables »
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20.4.2. MySQL Cluster-Related Command Options for mysqld

This section provides descriptions of mysqld server options relating to MySQL Cluster. For information about mysqld options not specific to MySQL Cluster, and for general information about the use of options with mysqld, see Section 5.1.2, “Command Options”.

For information about command-line options used with other MySQL Cluster processes (ndbd, ndb_mgmd, and ndb_mgm), see Section 20.6.5, “Command Options for MySQL Cluster Processes”. For information about command-line options used with NDB utility programs (such as ndb_desc, ndb_size.pl, and ndb_show_tables), see Section 20.10, “Cluster Utility Programs”.

  • --ndb-cluster-connection-pool=#

    By setting this option to a value greater than 1 (the default), a mysqld process can use multiple connections to the cluster, effectively mimicking several SQL nodes. Each connection requires its own [api] or [mysqld] section in the cluster configuration (config.ini) file, and counts against the maximum number of API connections supported by the cluster. For example, suppose that you have 2 cluster host computers, each running an SQL node whose mysqld process was started with --ndb-cluster-connection-pool=4; this means that the cluster must have 8 API slots available for these connections (instead of 2). All of these connections are set up when the SQL node connects to the cluster, and are allocated to threads in a round-robin fashion.

    Important

    This option is useful only when running mysqld on host machines having multiple CPUs, multiple cores, or both. For best results, the value should be smaller than the total number of cores available on the host machine. Setting it to a value greater than this is likely to degrade performance severely.

    Beginning with MySQL Cluster NDB 6.2.16 and MySQL Cluster NDB 6.3.13, the value used for this option is available as a global status variable. (Bug#35573)

  • --ndb-connectstring=connect_string

    When using the NDBCLUSTER storage engine, this option specifies the management server that distributes cluster configuration data.

  • --ndbcluster

    The NDB (or NDBCLUSTER) storage engine is necessary for using MySQL Cluster. If a mysqld binary includes support for the NDB storage engine, the engine is disabled by default. Use the --ndbcluster option to enable it. Use --skip-ndbcluster to explicitly disable the engine.

  • --skip-ndbcluster

    Disable the NDB storage engine. This is the default for binaries that were built with NDB storage engine support; the server allocates memory and other resources for this storage engine only if the --ndbcluster option is given explicitly. See Section 20.3.3, “Quick Test Setup of MySQL Cluster”, for an example of usage.