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MySQL 5.6 Reference Manual  /  ...  /  Options, Variables, and Parameters Added, Deprecated or Removed in NDB 7.4

18.1.5.2 Options, Variables, and Parameters Added, Deprecated or Removed in NDB 7.4

The next few sections contain information about NDB node configuration parameters and NDB-specific mysqld options and variables that have been added to, deprecated in, or removed from NDB 7.4.

Parameters Introduced in NDB 7.4

The following node configuration parameters have been added in NDB 7.4.

  • ApiVerbose: Enable NDB API debugging; for NDB development. Added in NDB 7.4.12.

  • BackupDiskWriteSpeedPct: Sets percentage of data node's allocated maximum write speed (MaxDiskWriteSpeed) to reserve for LCPs when starting backup. Added in NDB 7.4.8.

  • ConnectBackoffMaxTime: Specifies longest time in milliseconds (~100ms resolution) to allow between connection attempts to any given data node by this API node. Excludes time elapsed while connection attempts are ongoing, which in worst case can take several seconds. Disable by setting to 0. If no data nodes are currently connected to this API node, StartConnectBackoffMaxTime is used instead. Added in NDB 7.4.2.

  • DiskPageBufferEntries: Memory to allocate in DiskPageBufferMemory; very large disk transactions may require increasing this value. Added in NDB 7.4.3.

  • MaxDiskWriteSpeed: Maximum number of bytes per second that can be written by LCP and backup when no restarts are ongoing. Added in NDB 7.4.1.

  • MaxDiskWriteSpeedOtherNodeRestart: Maximum number of bytes per second that can be written by LCP and backup when another node is restarting. Added in NDB 7.4.1.

  • MaxDiskWriteSpeedOwnRestart: Maximum number of bytes per second that can be written by LCP and backup when this node is restarting. Added in NDB 7.4.1.

  • MaxParallelCopyInstances: Number of parallel copies during node restarts. Default is 0, which uses number of LDMs on both nodes, to maximum of 16. Added in NDB 7.4.3.

  • MinDiskWriteSpeed: Minimum number of bytes per second that can be written by LCP and backup. Added in NDB 7.4.1.

  • SchedulerResponsiveness: Set NDB scheduler response optimization 0-10; higher values provide better response time but lower throughput. Added in NDB 7.4.9.

  • StartConnectBackoffMaxTime: Same as ConnectBackoffMaxTime except that this parameter is used in its place if no data nodes are connected to this API node. Added in NDB 7.4.2.

  • TimeBetweenGlobalCheckpointsTimeout: Minimum timeout for group commit of transactions to disk. Added in NDB 7.4.5.

Parameters Deprecated in NDB 7.4

The following node configuration parameters have been deprecated in NDB 7.4.

  • BackupMemory: Total memory allocated for backups per node (in bytes). Deprecated in NDB 7.4.8.

  • DiskCheckpointSpeed: Bytes allowed to be written by checkpoint, per second. Deprecated in NDB 7.4.1.

  • DiskCheckpointSpeedInRestart: Bytes allowed to be written by checkpoint during restart, per second. Deprecated in NDB 7.4.1.

Parameters Removed in NDB 7.4

No node configuration parameters have been removed in NDB 7.4.

Options and Variables Introduced in NDB 7.4

The following system variables, status variables, and server options have been added in NDB 7.4.

  • Ndb_conflict_fn_epoch2: Number of rows that have been found in conflict by NDB$EPOCH2() conflict detection function. Added in NDB 7.4.2.

  • Ndb_conflict_fn_epoch2_trans: Number of rows that have been found in conflict by NDB$EPOCH2_TRANS() conflict detection function. Added in NDB 7.4.2.

  • Ndb_conflict_fn_max_del_win: Number of times that conflict resolution based on outcome of NDB$MAX_DELETE_WIN() has been applied. Added in NDB 7.4.1.

  • Ndb_conflict_last_conflict_epoch: Most recent NDB epoch on this replica in which some conflict was detected. Added in NDB 7.4.2.

  • Ndb_conflict_last_stable_epoch: Number of rows found to be in conflict by transactional conflict function. Added in NDB 7.4.2.

  • Ndb_conflict_reflected_op_discard_count: Number of reflected operations that were not applied due error during execution. Added in NDB 7.4.2.

  • Ndb_conflict_reflected_op_prepare_count: Number of reflected operations received that have been prepared for execution. Added in NDB 7.4.2.

  • Ndb_conflict_refresh_op_count: Number of refresh operations that have been prepared. Added in NDB 7.4.2.

  • Ndb_conflict_trans_row_conflict_count: Number of rows found in conflict by transactional conflict function. Includes any rows included in or dependent on conflicting transactions. Added in NDB 7.4.2.

  • Ndb_epoch_delete_delete_count: Number of delete-delete conflicts detected (delete operation is applied, but row does not exist). Added in NDB 7.4.2.

  • Ndb_last_commit_epoch_server: Epoch most recently committed by NDB. Added in NDB 7.4.1.

  • Ndb_last_commit_epoch_session: Epoch most recently committed by this NDB client. Added in NDB 7.4.1.

  • Ndb_slave_max_replicated_epoch: Most recently committed NDB epoch on this replica. When this value is greater than or equal to Ndb_conflict_last_conflict_epoch, no conflicts have yet been detected. Added in NDB 7.4.1.

  • create_old_temporals: Use pre-5.6.4 storage format for temporal types when creating tables. Intended for use in replication and upgrades/downgrades between NDB 7.2 and NDB 7.3/7.4. Added in NDB 7.4.7.

  • ndb-log-exclusive-reads: Log primary key reads with exclusive locks; allow conflict resolution based on read conflicts. Added in NDB 7.4.1.

  • ndb-log-fail-terminate: Terminate mysqld process if complete logging of all found row events is not possible. Added in NDB 7.4.28.

  • ndb-log-update-minimal: Log updates in minimal format. Added in NDB 7.4.16.

  • ndb_clear_apply_status: Causes RESET SLAVE/RESET REPLICA to clear all rows from ndb_apply_status table; ON by default. Added in NDB 7.4.9.

  • ndb_eventbuffer_free_percent: Percentage of free memory that should be available in event buffer before resumption of buffering, after reaching limit set by ndb_eventbuffer_max_alloc. Added in NDB 7.4.3.

  • ndb_log_exclusive_reads: Log primary key reads with exclusive locks; allow conflict resolution based on read conflicts. Added in NDB 7.4.1.

  • ndb_slave_conflict_role: Role for replica to play in conflict detection and resolution. Value is one of PRIMARY, SECONDARY, PASS, or NONE (default). Can be changed only when replication SQL thread is stopped. See documentation for further information. Added in NDB 7.4.1.

Options and Variables Deprecated in NDB 7.4

The following system variables, status variables, and options have been deprecated in NDB 7.4.

  • create_old_temporals: Use pre-5.6.4 storage format for temporal types when creating tables. Intended for use in replication and upgrades/downgrades between NDB 7.2 and NDB 7.3/7.4. Deprecated in NDB 7.4.7.

Options and Variables Removed in NDB 7.4

No system variables, status variables, or options have been removed in NDB 7.4.