Changes in MySQL NDB Cluster 7.6.19 (5.7.35-ndb-7.6.19) (2021-07-21, General Availability)

MySQL NDB Cluster 7.6.19 is a new release of NDB 7.6, based on MySQL Server 5.7 and including features in version 7.6 of the NDB storage engine, as well as fixing recently discovered bugs in previous NDB Cluster releases.

Obtaining NDB Cluster 7.6.  NDB Cluster 7.6 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/.

For an overview of changes made in NDB Cluster 7.6, see What is New in NDB Cluster 7.6.

This release also incorporates all bug fixes and changes made in previous NDB Cluster releases, as well as all bug fixes and feature changes which were added in mainline MySQL 5.7 through MySQL 5.7.35 (see Changes in MySQL 5.7.35 (2021-07-20, General Availability)).

• Functionality Added or Changed

• Bugs Fixed

Functionality Added or Changed

• ndb_restore now supports conversion between NULL and NOT NULL columns, as follows:

  • To restore a NULL column as NOT NULL, use the --lossy-conversions option. The presence of any NULL rows in the column causes ndb_restore to raise an and exit.

  • To restore a NOT NULL column as NULL, use the --promote-attributes option.

  For more information, see the descriptions of the indicated ndb_restore options. (Bug #32702637)

Bugs Fixed

• Packaging: The ndb-common man page was removed, and the information it contained moved to other man pages. (Bug #32799519)

• NDB Cluster APIs: Added the NDB_LE_EventBufferStatus3 log event type to Ndb_logevent_type in the MGM API. This is an extension of the NDB_LE_EventBufferStatus type which handles total, maximum, and allocated bytes as 64-bit values.

  As part of this fix, the maximum value of the ndb_eventbuffer_max_alloc server system variable is increased to 9223372036854775807 (2⁶³ - 1).

  For more information, see The Ndb_logevent_type Type. (Bug #32381666)

• Ndb_rep_tab_key member variables were not null-terminated before being logged. (Bug #32841430)

  References: See also: Bug #32393245.

• Some error messages printed by ndb_restore tried to access transactions that were already closed for error information, resulting in an unplanned exit. (Bug #32815725)

• Returning an error while determining the number of partitions used by a NDB table caused the MySQL server to write Incorrect information in table.frm file to its error log, despite the fact that the indicated file did not exist. This also led to problems with flooding of the error log when users attempted to open NDB tables while the MySQL server was not actually connected to NDB.

  We fix this by changing the function that determines the number of partitions to return 0 whenever NDB is not available, thus deferring any error detection until the MySQL server is once again connected to NDB. (Bug #32713166)

• Using duplicate node IDs with CREATE NODEGROUP (for example, CREATE NODEGROUP 11, 11) could lead to an unplanned shutdown of the cluster. Now when this command includes duplicate node IDs, it raises an error. (Bug #32701583)

• Improved the performance of queries against the ndbinfo.cluster_locks table, which could in some cases run quite slowly. (Bug #32655988)

• It was possible in some cases to miss the end point of undo logging for a fragment. (Bug #32623528)

  References: See also: Bug #31774459.

• The --resume option for ndb_import did not work correctly unless the --stats option was also specified. (Bug #31107058)

• A DELETE statement whose WHERE clause referred to a BLOB column was not executed correctly. (Bug #13881465)