NDB Cluster Configuration Files Multi-Threading Configuration Parameters (ndbmtd).  ndbmtd  runs by default as a single-threaded process and must be configured to use multiple threads, using either of two methods, both of which require setting configuration parameters in the  config.ini  file. The first method is simply to set an appropriate value for the  MaxNoOfExecutionThreads  configuration parameter. A second method, makes it possible to set up more complex rules for  ndbmtd  multithreading using  ThreadConfig . The next few paragraphs provide information about these parameters and their use with multithreaded data nodes. A backup using parallelism on the data nodes requires that multiple LDMs are in use on all data nodes in the cluster prior to taking the backup. For more information, see Section 23.5.8.5, “Taking an NDB Backup with Parallel Data Nodes” , as well as Section 23.4.23.3, “Restoring from a backup taken in parallel” . When set to 1, enables automatic thread configuration employing the number of CPUs available to a data node taking into account any limits set by  taskset ,  numactl , virtual machines, Docker, and other such means of controlling which CPUs are available to a given application (on Windows platforms, automatic thread configuration uses all CPUs which are online); alternatively, you can set  NumCPUs to the desired number of CPUs (up to 1024, the maximum number of CPUs that can be handled by automatic thread configuration). Any settings for  ThreadConfig  and  MaxNoOfExecutionThreads are ignored. When enabled (set to  true ),  NDB  uses flexible distribution of table fragents among LDMs. This means that the default number of partitions per node is equal to  PartitionsPerNode , rather than to the minimum number of LDM threads per data node, and that each table has a number of partitions equal to 4 (the default for  PartitionsPerNode ) times the number of data nodes. For new clusters for which a downgrade to NDB 8.0.22 or earlier is never expected to occur, setting ClassicFragmentation  to  false  when first setting up the cluster is preferable; this ensures that all partitions are spread out evenly between all LDMs. 4128 • MaxNoOfExecutionThreads • ClassicFragmentation • AutomaticThreadConfig Note Version (or later) NDB 8.0.23 Type or units boolean Default false Range true, false Added NDB 8.0.23 Restart Type IS (NDB 8.0.13) Version (or later) NDB 8.0.23 Type or units boolean Default true Range true, false Added NDB 8.0.23 Restart Type N (NDB 8.0.13)