MySQL NDB Cluster 7.4.31 is a new release of MySQL NDB Cluster
7.4, based on MySQL Server 5.6 and including features in version
7.4 of the
NDB storage engine, as
well as fixing recently discovered bugs in previous NDB Cluster
Obtaining MySQL NDB Cluster 7.4. MySQL NDB Cluster 7.4 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/.
For an overview of changes made in MySQL NDB Cluster 7.4, see What is New in NDB Cluster 7.4.
This release also incorporates all bug fixes and changes made in previous NDB Cluster releases.
NDB Client Programs: Effective with this release, the MySQL NDB Cluster Auto-Installer (ndb_setup.py) has been has been removed from the NDB Cluster binary and source distributions, and is no longer supported. (Bug #32084831)
References: See also: Bug #31888835.
ndbmemcache, which was deprecated in the previous release of NDB Cluster, has now been removed from NDB Cluster, and is no longer supported. (Bug #32106576)
Using the maximum size of an index key supported by index statistics (3056 bytes) caused buffer issues in data nodes. (Bug #32094904)
References: See also: Bug #25038373.
When a table creation schema transaction is prepared, the table is in
TS_CREATINGstate, and is changed to
TS_ACTIVEstate when the schema transaction commits on the
DBDIHblock. In the case where the node acting as
DBDIHcoordinator fails while the schema transaction is committing, another node starts taking over for the coordinator. The following actions are taken when handling this node failure:
DBDICTrolls the table creation schema transaction forward and commits, resulting in the table involved changing to
DBDIHstarts removing the failed node from tables by moving active table replicas on the failed node from a list of stored fragment replicas to another list.
These actions are performed asynchronously many times, and when interleaving may cause a race condition. As a result, the replica list in which the replica of a failed node resides becomes nondeterministic and may differ between the recovering node (that is, the new coordinator) and other
DIHparticipant nodes. This difference violated a requirement for knowing which list the failed node's replicas can be found during the recovery of the failed node recovery on the other participants.
To fix this, moving active table replicas now covers not only tables in
TS_ACTIVEstate, but those in
TS_CREATING(prepared) state as well, since the prepared schema transaction is always rolled forward.
In addition, the state of a table creation schema transaction which is being aborted is now changed from
TS_DROPPING, to avoid any race condition there. (Bug #30521812)