Id

The Id is an integer value used to identify the node in all cluster internal messages. Prior to MySQL Cluster NDB 6.1.1, the permitted range of values for this parameter was 1 to 63 inclusive. Beginning with MySQL Cluster NDB 6.1.1, the permitted range is 1 to 255 inclusive. This value must be unique for each node in the cluster, regardless of the type of node.

This parameter can also be written as NodeId, although the short form is sufficient (and preferred for this reason).

ExecuteOnComputer

This refers to the Id set for one of the computers (hosts) defined in a [computer] section of the configuration file.

HostName

Specifying this parameter defines the hostname of the computer on which the SQL node (API node) is to reside. To specify a hostname, either this parameter or ExecuteOnComputer is required.

If no HostName or ExecuteOnComputer is specified in a given [mysql] or [api] section of the config.ini file, then an SQL or API node may connect using the corresponding “slot” from any host which can establish a network connection to the management server host machine. This differs from the default behavior for data nodes, where localhost is assumed for HostName unless otherwise specified.

ArbitrationRank

This parameter defines which nodes can act as arbitrators. Both MGM nodes and SQL nodes can be arbitrators. A value of 0 means that the given node is never used as an arbitrator, a value of 1 gives the node high priority as an arbitrator, and a value of 2 gives it low priority. A normal configuration uses the management server as arbitrator, setting its ArbitrationRank to 1 (the default for management nodes) and those for all SQL nodes to 0 (the default for SQL nodes).

Beginning with MySQL 5.1.16 and MySQL Cluster NDB 6.1.3, it is possible to disable arbitration completely by setting ArbitrationRank to 0 on all management and SQL nodes. In MySQL Cluster NDB 7.0.7 and later releases, you can also control arbitration by overriding this parameter; to do this, set the Arbitration parameter in the [ndbd default] section of the config.ini global configuration file.

ArbitrationDelay

Setting this parameter to any other value than 0 (the default) means that responses by the arbitrator to arbitration requests will be delayed by the stated number of milliseconds. It is usually not necessary to change this value.

BatchByteSize

For queries that are translated into full table scans or range scans on indexes, it is important for best performance to fetch records in properly sized batches. It is possible to set the proper size both in terms of number of records (BatchSize) and in terms of bytes (BatchByteSize). The actual batch size is limited by both parameters.

The speed at which queries are performed can vary by more than 40% depending upon how this parameter is set. In future releases, MySQL Server will make educated guesses on how to set parameters relating to batch size, based on the query type.

This parameter is measured in bytes and by default is equal to 32KB.

BatchSize

This parameter is measured in number of records and is by default set to 64. The maximum size is 992.

HeartbeatThreadPriority

Beginning with MySQL Cluster NDB 6.3.32, MySQL Cluster NDB 7.0.13, and MySQL Cluster NDB 7.1.2, it is possible to use this parameter to set the scheduling policy and priority of heartbeat threads for management and API nodes.

The syntax for setting this parameter is shown here:

HeartbeatThreadPriority = policy[, priority]
policy:
  {FIFO | RR}

When setting this parameter, you must specify a policy. This is one of FIFO (first in, first in) or RR (round robin). This followed optionally by the priority (an integer).

MaxScanBatchSize

The batch size is the size of each batch sent from each data node. Most scans are performed in parallel to protect the MySQL Server from receiving too much data from many nodes in parallel; this parameter sets a limit to the total batch size over all nodes.

The default value of this parameter is set to 256KB. Its maximum size is 16MB.

TotalSendBufferMemory

This parameter is available beginning with MySQL Cluster NDB 6.4.0. It is used to determine the total amount of memory to allocate on this node for shared send buffer memory among all configured transporters.

If this parameter is set, its minimum allowed value is 256K; the maxmimum is 4294967039. For more detailed information about the behavior and use of TotalSendBufferMemory and configuring send buffer memory parameters in MySQL Cluster NDB 6.4.0 and later, see Section 3.2.13, “Configuring MySQL Cluster Send Buffer Parameters”.

AutoReconnect

This parameter is available beginning with MySQL Cluster NDB 6.3.26 and MySQL Cluster NDB 7.0.7. By default, its value is false, which forces disconnected API nodes (including MySQL Servers acting as SQL nodes) the use a new connection to the cluster rather than attempting to re-use an existing one, which can cause problems when using dynamically-allocated node IDs. (Bug#45921)