17.3.4.1 MySQL Cluster Server Option and Variable Reference

The following table provides a list of the command-line options, server and status variables applicable within mysqld when it is running as an SQL node in a MySQL Cluster. For a table showing all command-line options, server and status variables available for use with mysqld, see Section 5.1.1, “Server Option and Variable Reference”.

Table 17.8  MySQL Server Options and Variables for MySQL Cluster: MySQL 5.0

Option or Variable Name
Command Line System Variable Status Variable
Option File Scope Dynamic
Notes

Handler_discover

No No Yes
No Both No

DESCRIPTION: Number of times that tables have been discovered

ndb_autoincrement_prefetch_sz

Yes Yes No
Yes Both Yes

DESCRIPTION: NDB auto-increment prefetch size

ndb_cache_check_time

Yes Yes No
Yes Global Yes

DESCRIPTION: Number of milliseconds between checks of cluster SQL nodes made by the MySQL query cache

ndb-connectstring

Yes No No
Yes No

DESCRIPTION: Point to the management server that distributes the cluster configuration

ndb_force_send

Yes Yes No
Yes Both Yes

DESCRIPTION: Forces sending of buffers to NDB immediately, without waiting for other threads

ndb_use_exact_count

No Yes No
No Both Yes

DESCRIPTION: Use exact row count when planning queries

ndb-nodeid

Yes No Yes
Yes Global No

DESCRIPTION: MySQL Cluster node ID for this MySQL server

ndb-mgmd-host

Yes No No
Yes No

DESCRIPTION: Set the host (and port, if desired) for connecting to management server

ndbcluster

Yes No No
Yes No

DESCRIPTION: Enable NDB Cluster (if this version of MySQL supports it)

Disabled by --skip-ndbcluster

have_ndbcluster

No Yes No
No Global No

DESCRIPTION: Whether mysqld supports NDB Cluster tables (set by --ndbcluster option)

ndb_index_stat_cache_entries

Yes Yes No
Yes Both Yes

DESCRIPTION: Sets the granularity of the statistics by determining the number of starting and ending keys

ndb_index_stat_enable

Yes Yes No
Yes Both Yes

DESCRIPTION: Use NDB index statistics in query optimization

ndb_index_stat_update_freq

Yes Yes No
Yes Both Yes

DESCRIPTION: How often to query data nodes instead of the statistics cache

ndb_optimized_node_selection

Yes Yes No
Yes Global No

DESCRIPTION: Determines how an SQL node chooses a cluster data node to use as transaction coordinator

ndb_report_thresh_binlog_epoch_slip

Yes No No
Yes No

DESCRIPTION: This is a threshold on the number of epochs to be behind before reporting binary log status

ndb_report_thresh_binlog_mem_usage

Yes No No
Yes No

DESCRIPTION: This is a threshold on the percentage of free memory remaining before reporting binary log status

ndb_use_transactions

Yes Yes No
Yes Both Yes

DESCRIPTION: Forces NDB to use a count of records during SELECT COUNT(*) query planning to speed up this type of query

Ndb_cluster_node_id

No No Yes
No Both No

DESCRIPTION: If the server is acting as a MySQL Cluster node, then the value of this variable its node ID in the cluster

Ndb_config_from_host

No No Yes
No Both No

DESCRIPTION: The host name or IP address of the Cluster management server. Formerly Ndb_connected_host

Ndb_config_from_port

No No Yes
No Both No

DESCRIPTION: The port for connecting to Cluster management server. Formerly Ndb_connected_port

Com_show_ndb_status

No No Yes
No Both No

DESCRIPTION: Count of SHOW NDB STATUS statements