NDB Cluster Configuration Files of the higher rate of I/O and greater bandwidth available from modern solid-state storage devices and protocols, such as solid-state drives (SSDs) using Non-Volatile Memory Express (NVMe). The parameter currently defaults to  false  (disabled) due to the fact that  NDB  is still deployed widely on systems whose I/O or bandwidth is constrained relative to those employing solid-state technology, such as those using conventional hard disks (HDDs). In settings such as these, the  EnableRedoControl mechanism can easily cause the I/O subsystem to become saturated, increasing wait times for data node input and output. In particular, this can cause issues with NDB Disk Data tables which have tablespaces or log file groups sharing a constrained IO subsystem with data node LCP and redo log files; such problems potentially include node or cluster failure due to GCP stop errors. Metadata objects.   The next set of  [ndbd]  parameters defines pool sizes for metadata objects, used to define the maximum number of attributes, tables, indexes, and trigger objects used by indexes, events, and replication between clusters. These act merely as “suggestions”  to the cluster, and any that are not specified revert to the default values shown. This parameter sets a suggested maximum number of attributes that can be defined in the cluster; like MaxNoOfTables , it is not intended to function as a hard upper limit. (In older NDB Cluster releases, this parameter was sometimes treated as a hard limit for certain operations. This caused problems with NDB Cluster Replication, when it was possible to create more tables than could be replicated, and sometimes led to confusion when it was possible [or not possible, depending on the circumstances] to create more than  MaxNoOfAttributes  attributes.) The default value is 1000, with the minimum possible value being 32. The maximum is 4294967039. Each attribute consumes around 200 bytes of storage per node due to the fact that all metadata is fully replicated on the servers. When setting  MaxNoOfAttributes , it is important to prepare in advance for any  ALTER TABLE  statements that you might want to perform in the future. This is due to the fact, during the execution of  ALTER TABLE  on a Cluster table, 3 times the number of attributes as in the original table are used, and a good practice is to permit double this amount. For example, if the NDB Cluster table having the greatest number of attributes ( greatest_number_of_attributes ) has 100 attributes, a good starting point for the value of  MaxNoOfAttributes  would be  6 * greatest_number_of_attributes  = 600 . You should also estimate the average number of attributes per table and multiply this by MaxNoOfTables . If this value is larger than the value obtained in the previous paragraph, you should use the larger value instead. 4095 • MaxNoOfAttributes Version (or later) NDB 8.0.13 Type or units integer Default 1000 Range 32 - 4294967039 (0xFFFFFEFF) Restart Type N (NDB 8.0.13) Note