MySQL Cluster 7.4.31 has been released

[Rafal Molenda]

Dear MySQL Users,

MySQL Cluster is the distributed, shared-nothing variant of MySQL.
This storage engine provides:

  - In-Memory storage - Real-time performance (with optional
    checkpointing to disk)
  - Transparent Auto-Sharding - Read & write scalability
  - Active-Active/Multi-Master geographic replication
  - 99.999% High Availability with no single point of failure
    and on-line maintenance
  - NoSQL and SQL APIs (including C++, Java, http, Memcached
    and JavaScript/Node.js)

MySQL Cluster 7.4 makes significant advances in performance;
operational efficiency (such as enhanced reporting and faster restarts
and upgrades) and conflict detection and resolution for active-active
replication between MySQL Clusters.

MySQL Cluster 7.4.31 has been released and can be downloaded from

  http://www.mysql.com/downloads/cluster/

where you will also find Quick Start guides to help you get your
first MySQL Cluster database up and running.

The release notes are available from

  http://dev.mysql.com/doc/relnotes/mysql-cluster/7.4/en/index.html

MySQL Cluster enables users to meet the database challenges of next
generation web, cloud, and communications services with uncompromising
scalability, uptime and agility.

More details can be found at

  http://www.mysql.com/products/cluster/

Enjoy !


==============================================================================
Changes in MySQL NDB Cluster 7.4.31 (5.6.51-ndb-7.4.31) (2021-01-19, General Availability)

   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 releases.

   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
   (https://dev.mysql.com/doc/refman/5.6/en/mysql-cluster-what-is-new-7-4.html).

   This release also incorporates all bug fixes and changes made
   in previous NDB Cluster releases.

     * Deprecation and Removal Notes

     * Bugs Fixed


Deprecation and Removal Notes


       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: 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)


Bugs Fixed


       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_CREATING state, and is changed to
       TS_ACTIVE state when the schema transaction commits on
       the DBDIH block. In the case where the node acting as
       DBDIH coordinator 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:

          + DBDICT rolls the table creation schema transaction
            forward and commits, resulting in the table involved
            changing to TS_ACTIVE state.

          + DBDIH starts 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
       failed node resides becomes nondeterministic and may
       differ between the recovering node (that is, the new
       coordinator) and other DIH participant 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_ACTIVE state, 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_CREATING or TS_IDLE to TS_DROPPING, to avoid any race
       condition there. (Bug #30521812)


On Behalf of MySQL Release Engineering Team,
Rafal Molenda