Cluster API: Important Change: Because NDB_LE_MemoryUsage.page_size_kb shows memory page sizes in bytes rather than kilobytes, it has been renamed to page_size_bytes. The name page_size_kb is now deprecated and thus subject to removal in a future release, although it currently remains supported for reasons of backward compatibility. See The Ndb_logevent_type Type, for more information about NDB_LE_MemoryUsage. (Bug#30271)

MySQL Cluster: ndb_restore now supports basic attribute promotion; that is, data from a column of a given type can be restored to a column using a “larger” type. For example, Cluster backup data taken from a SMALLINT column can be restored to a MEDIUMINT, INT, or BIGINT column.

For more information, see Section 16.9.3, “ndb_restore — Restore a Cluster Backup”.

MySQL Cluster: Now only 2 local checkpoints are stored, rather than 3 as in previous MySQL Cluster versions. This lowers disk space requirements and reduces the size and number of redo log files needed.

MySQL Cluster: The mysqld option --ndb-batch-size has been added. This allows for controlling the size of batches used for running transactions.

MySQL Cluster: Node recovery can now be done in parallel, rather than sequentially, which can result in much faster recovery times.

MySQL Cluster: Persistence of NDB tables can now be controlled using the session variables ndb_table_temporary and ndb_table_no_logging. ndb_table_no_logging causes NDB tables not to be checkpointed to disk; ndb_table_temporary does the same, and in addition, no schema files are created.

MySQL Cluster: OPTIMIZE TABLE can now be interrupted. This can be done, for example, by killing the SQL thread performing the OPTIMIZE operation.

Disk Data: Important Change: It is no longer possible on 32-bit systems to issue statements appearing to create Disk Data log files or data files greater than 4 GB in size. (Trying to create log files or data files larger than 4 GB on 32-bit systems led to unrecoverable data node failures; such statements now fail with NDB error 1515.) (Bug#29186)

Replication: MySQL Cluster: The code implementing heartbeats did not check for possible errors in some circumstances; this kept the dump thread hanging while waiting for heartbeats loop even though the slave was no longer connected. (Bug#33332)

MySQL Cluster: High numbers of insert operations, delete operations, or both could cause NDB error 899 (Rowid already allocated) to occur unnecessarily. (Bug#34033)

MySQL Cluster: A periodic failure to flush the send buffer by the NDB TCP transporter could cause a unnecessary delay of 10 ms between operations. (Bug#34005)

MySQL Cluster: DROP TABLE did not free all data memory. This bug was observed in MySQL Cluster NDB 6.3.7 only. (Bug#33802)

MySQL Cluster: A race condition could occur (very rarely) when the release of a GCI was followed by a data node failure. (Bug#33793)

MySQL Cluster: Some tuple scans caused the wrong memory page to be accessed, leading to invalid results. This issue could affect both in-memory and Disk Data tables. (Bug#33739)

MySQL Cluster: A failure to initialize an internal variable led to sporadic crashes during cluster testing. (Bug#33715)

MySQL Cluster: The server failed to reject properly the creation of an NDB table having an unindexed AUTO_INCREMENT column. (Bug#30417)

MySQL Cluster: Issuing an INSERT ... ON DUPLICATE KEY UPDATE concurrently with or following a TRUNCATE statement on an NDB table failed with NDB error 4350 Transaction already aborted. (Bug#29851)

MySQL Cluster: The Cluster backup process could not detect when there was no more disk space and instead continued to run until killed manually. Now the backup fails with an appropriate error when disk space is exhausted. (Bug#28647)

MySQL Cluster: It was possible in config.ini to define cluster nodes having node IDs greater than the maximum allowed value. (Bug#28298)

MySQL Cluster: Under some circumstances, a recovering data node did not use its own data, instead copying data from another node even when this was not required. This in effect bypassed the optimized node recovery protocol and caused recovery times to be unnecessarily long. (Bug#26913)

Cluster Replication: Consecutive DDL statements involving tables (CREATE TABLE, ALTER TABLE, and DROP TABLE) could be executed so quickly that previous DDL statements upon which they depended were not yet written in the binary log.

For example, if DROP TABLE foo was issued immediately following CREATE TABLE foo, the DROP statement could fail because the CREATE had not yet been recorded. (Bug#34006)

Cluster Replication: ndb_restore -e restored excessively large values to the ndb_apply_status table's epoch column when restoring to a MySQL Cluster version supporting Micro-GCPs from an older version that did not support these.

A workaround when restoring to MySQL Cluster releases supporting micro-GCPs previous to MySQL Cluster NDB 6.3.8 is to perform a 32-bit shift on the epoch column values to reduce them to their proper size. (Bug#33406)

Cluster API: Transactions containing inserts or reads would hang during NdbTransaction::execute() calls made from NDB API applications built against a MySQL Cluster version that did not support micro-GCPs accessing a later version that supported micro-GCPs. This issue was observed while upgrading from MySQL Cluster NDB 6.1.23 to MySQL Cluster NDB 6.2.10 when the API application built against the earlier version attempted to access a data node already running the later version, even after disabling micro-GCPs by setting TimeBetweenEpochs equal to 0. (Bug#33895)

Cluster API: When reading a BIT(64) value using NdbOperation:getValue(), 12 bytes were written to the buffer rather than the expected 8 bytes. (Bug#33750)