NDB Cluster Configuration Files N (NDB 8.0.13) Restart Type This parameter 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 permitted value is 256KB; 0 indicates that the parameter has not been set. For more detailed information, see Section 23.3.3.14, “Configuring NDB Cluster Send Buffer Parameters” . Specify the interval between heartbeat messages used to determine whether another management node is on contact with this one. The management node waits after 3 of these intervals to declare the connection dead; thus, the default setting of 1500 milliseconds causes the management node to wait for approximately 1600 ms before timing out. After making changes in a management node’s configuration, it is necessary to perform a rolling restart of the cluster for the new configuration to take effect. To add new management servers to a running NDB Cluster, it is also necessary to perform a rolling restart of all cluster nodes after modifying any existing config.ini  files. For more information about issues arising when using multiple management nodes, see Section 23.1.7.10, “Limitations Relating to Multiple NDB Cluster Nodes” . Restart types.   Information about the restart types used by the parameter descriptions in this section is shown in the following table: 23.3.3.6 Defining NDB Cluster Data Nodes Table 23.9 NDB Cluster restart types 4068 Symbol Restart Type Description N Node The parameter can be updated using a rolling restart (see Section 23.5.5, “Performing a Rolling Restart of an NDB Cluster” ) S System All cluster nodes must be shut down completely, then restarted, to effect a change in this parameter I Initial Data nodes must be restarted using the  --initial  option Note Version (or later) NDB 8.0.13 Type or units milliseconds Default 1500 Range 100 - 4294967039 (0xFFFFFEFF) Restart Type N (NDB 8.0.13) • HeartbeatIntervalMgmdMgmd