MySQL NDB Cluster 7.6.16 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 5.7.32 (see Changes in MySQL 5.7.32 (2020-10-19, General Availability)).
NDB Cluster APIs: Support for Node.js has been removed in this release.
Node.js continues to be supported in NDB Cluster 8.0 only. (Bug #31781948)
NDB Client Programs: Effective with this release, the MySQL NDB Cluster Auto-Installer (ndb_setup.py) has been deprecated and is subject to removal in a future version of NDB Cluster. (Bug #31888835)
ndbmemcacheis deprecated in this release of NDB Cluster, and is scheduled for removal in the next release. (Bug #31876970)
Packaging: The Dojo library included with NDB Cluster has been upgraded to version 1.15.4. (Bug #31559518)
NDB Cluster APIs: It was possible to make invalid sequences of NDB API method calls using blobs. This was because some method calls implicitly cause transaction execution inline, to deal with blob parts and other issues, which could cause user-defined operations not to be handled correctly due to the use of a method executing operations relating to blobs while there still user-defined blob operations pending. Now in such cases, NDB raises a new error 4558 Pending blob operations must be executed before this call. (Bug #27772916)
After encountering the data node in the configuration file which used
NodeGroup=65536, the management server stopped assigning data nodes lacking an explicit
NodeGroupsetting to node groups. (Bug #31825181)
During different phases of the restore process, ndb_restore used different numbers of retries for temporary errors as well as different sleep times between retries. This is fixed by implementing consistent retry counts and sleep times across all restore phases. (Bug #31372923)
Backups errored out with FsErrInvalidParameters when the filesystem was running with
O_DIRECTand a data file write was not aligned with the 512-byte block size used by
O_DIRECTwrites. If the total fragment size in the data file is not aligned with the
NDBpads the last write to the required size, but when there were no fragments to write,
BACKUPwrote only the header and footer to the data file. Since the header and footer are less than 512 bytes, leading to the issue with the
This is fixed by padding out the generic footer to 512 bytes if necessary, using an
EMPTY_ENTRY, when closing the data file. (Bug #31180508)
Altering the table comment of a fully replicated table using
ALGORITHM=INPLACEled to an assertion. (Bug #31139313)
Data nodes did not start when the
RealtimeSchedulerconfiguration parameter was set to 1. This was due to the fact that index builds during startup are performed by temporarily diverting some I/O threads for use as index building threads, and these threads inherited the realtime properties of the I/O threads. This caused a conflict (treated as a fatal error) when index build thread specifications were checked to ensure that they were not realtime threads. This is fixed by making sure that index build threads are not treated as realtime threads regardless of any settings applying to their host I/O threads, which is as actually intended in their design. (Bug #27533538)