25.2.4 What is New in MySQL NDB Cluster 9.4

The following sections describe changes in the implementation of MySQL NDB Cluster in NDB Cluster 9.4.0, as compared to earlier release series. NDB Cluster 9.4 is available as a Development release for preview and testing of new features currently under development. For production, please use NDB 8.4; for more information, see MySQL NDB Cluster 8.4. NDB Cluster 8.0 and 7.6 are previous GA releases which are still supported in production, although we recommend that new deployments for production use MySQL NDB Cluster 8.4.

What is New in NDB Cluster 9.4

Major changes and new features in NDB Cluster 9.4 which are likely to be of interest are listed here:

• Binary log slicing.  Beinning with NDB 9.4.0, it is possible to divide binary logging for a MySQL Cluster or for individual NDBCLUSTER tables equally amongst multiple MySQL servers.

  For slicing and dividing the binary logging for an entire cluster, NDB implements two mysqld startup options: --ndb-log-row-slice-count determines the number of slices into which to divide the binary log, and thus the number of servers sharing logging duties; --ndb-log-row-slice-id identifies the slice for which a given MySQL server is responsible. See the descriptions of these options for more information.

  Log slicing can be done for a specific NDB table by adding rows to the ndb_replication table with appropriate values for the binlog_row_slice_count and binlog_row_slice_id columns which are implemented in NDB 9.4.0. For further information and examples, see Per-table binary log slicing.

• DEFAULT expressions.  Beginning with NDB 9.4.0, MySQL Cluster supports explicit default expressions for columns of NDB tables used with the MySQL server, as described in Section 13.6, “Data Type Default Values”.

  Default column value expressions are supported only when accessed using the MySQL server; such expressions are not visible to NDB API applications.

• Microsecond node log timestamps.  Timestamps in NDB node logs are now printed by default using microsecond resolution. Data nodes can enable this feature explicitly with the data node --ndb-log-timestamps=UTC option; management nodes can also do so using the ndb_mgmd option --ndb-log-timestamps=UTC. For backwards compatible behavior, set this option to LEGACY, which uses the system time zone and resolution in seconds, as in releases prior to NDB 8.4.6; in NDB 9.4, UTC is the default.

  SQL nodes can use the roughly equivalent option --log-timestamps; you should be aware that this mysqld option does not accept LEGACY as a value.

  For more information about NDB Cluster node logs, see Section 25.6.2, “NDB Cluster Log Messages”.

MySQL Cluster Manager has an advanced command-line interface that can simplify many complex NDB Cluster management tasks. See MySQL Cluster Manager 9.4.0 User Manual, for more information.