Overview of NDB Cluster Configuration Parameters, Options, and Variables 4036 • RecoveryWork : Percentage of storage overhead for LCP files: greater value means less work in normal operations, more work during recovery. • RealtimeScheduler : When true, data node threads are scheduled as real-time threads. Default is false. • ODirectSyncFlag : O_DIRECT writes are treated as synchronized writes; ignored when ODirect is not enabled, InitFragmentLogFiles is set to SPARSE, or both. • ODirect : Use O_DIRECT file reads and writes when possible. • Numa : (Linux only; requires libnuma) Controls NUMA support. Setting to 0 permits system to determine use of interleaving by data node process; 1 means that it is determined by data node. • NoOfReplicas : Number of copies of all data in database. • NoOfFragmentLogFiles : Number of 16 MB redo log files in each of 4 file sets belonging to data node. • NodeId : Number uniquely identifying data node among all nodes in cluster. • NodeGroupTransporters : Number of transporters to use between nodes in same node group. • NodeGroup : Node group to which data node belongs; used only during initial start of cluster. • MinFreePct : Percentage of memory resources to keep in reserve for restarts. • MinDiskWriteSpeed : Minimum number of bytes per second that can be written by LCP and backup. • MemReportFrequency : Frequency of memory reports in seconds; 0 = report only when exceeding percentage limits. • MaxUIBuildBatchSize : Maximum scan batch size to use for building unique keys. Increasing this value may speed up builds of unique keys but impacts ongoing traffic as well. • MaxStartFailRetries : Maximum retries when data node fails on startup, requires StopOnError = 0. Setting to 0 causes start attempts to continue indefinitely. • MaxReorgBuildBatchSize : Maximum scan batch size to use for reorganization of table partitions. Increasing this value may speed up table partition reorganization but impacts ongoing traffic as well. • MaxParallelScansPerFragment : Maximum number of parallel scans per fragment. Once this limit is reached, scans are serialized. • MaxParallelCopyInstances : Number of parallel copies during node restarts. Default is 0, which uses number of LDMs on both nodes, to maximum of 16. • MaxNoOfUniqueHashIndexes : Total number of unique hash indexes that can be defined in system. • MaxNoOfTriggers : Total number of triggers that can be defined in system. • MaxNoOfTables : Suggests total number of NDB tables stored in database. • MaxNoOfSubscriptions : Maximum number of subscriptions (default 0 = MaxNoOfTables). • MaxNoOfSubscribers : Maximum number of subscribers. • MaxNoOfSavedMessages : Maximum number of error messages to write in error log and maximum number of trace files to retain. • MaxNoOfOrderedIndexes : Total number of ordered indexes that can be defined in system.