What is New in NDB Cluster Deprecated variable Replacement Ndb_api_range_scan_count_slave Ndb_api_range_scan_count_replica Ndb_api_read_row_count_slave Ndb_api_read_row_count_replica Ndb_api_scan_batch_count_slave Ndb_api_scan_batch_count_replica Ndb_api_table_scan_count_slave Ndb_api_table_scan_count_replica Ndb_api_trans_abort_count_slave Ndb_api_trans_abort_count_replica Ndb_api_trans_close_count_slave Ndb_api_trans_close_count_replica Ndb_api_trans_commit_count_slave Ndb_api_trans_commit_count_replica Ndb_api_trans_local_read_row_count_slave Ndb_api_trans_local_read_row_count_replica Ndb_api_trans_start_count_slave Ndb_api_trans_start_count_replica Ndb_api_uk_op_count_slave Ndb_api_uk_op_count_replica Ndb_api_wait_exec_complete_count_slave Ndb_api_wait_exec_complete_count_replica Ndb_api_wait_meta_request_count_slave Ndb_api_wait_meta_request_count_replica Ndb_api_wait_nanos_count_slave Ndb_api_wait_nanos_count_replica Ndb_api_wait_scan_result_count_slave Ndb_api_wait_scan_result_count_replica Ndb_slave_max_replicated_epoch Ndb_replica_max_replicated_epoch The deprecated status variables continue to be shown in the output of  SHOW STATUS , but applications should be updated as soon as possible not to rely upon them any longer, since their availability in future release series is not guaranteed. 3953 • query : A query thread works (only) on  READ COMMITTED  queries. A query thread also acts as a recovery thread. The number of query threads must be 0, 1, 2, or 3 times the number of LDM threads. 0 (the default, unless using  ThreadConfig , or  AutomaticThreadConfig  is enabled) causes LDMs to behave as they did prior to NDB 8.0.23. • ThreadConfig enhancements.   As of NDB 8.0.23, the configurability of the  ThreadConfig parameter has been extended with two new thread types, listed here: •The  --help  output of some  NDB  client and utility programs such as  ndb_restore  has been modified. •The values  ADD_TABLE_MASTER  and  ADD_TABLE_SLAVE  previously shown in the tab_copy_status  column of the  ndbinfo ndbinfo.table_distribution_status  table are deprecated. These are replaced by, respectively, the values  ADD_TABLE_COORDINATOR  and ADD_TABLE_PARTICIPANT .