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MySQL NDB Cluster 7.4 Release Notes  /  Changes in MySQL NDB Cluster 7.4.20 (5.6.40-ndb-7.4.20) (2018-04-20, General Availability)

Changes in MySQL NDB Cluster 7.4.20 (5.6.40-ndb-7.4.20) (2018-04-20, General Availability)

MySQL NDB Cluster 7.4.20 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

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, as well as all bug fixes and feature changes which were added in mainline MySQL 5.6 through MySQL 5.6.40 (see Changes in MySQL 5.6.40 (2018-04-19, General Availability)).

Bugs Fixed

  • NDB Cluster APIs: The maximum time to wait which can be specified when calling either of the NDB API methods Ndb::pollEvents() or pollEvents2() was miscalculated such that the method could wait up to 9 ms too long before returning to the client. (Bug #88924, Bug #27266086)

  • Under certain conditions, data nodes restarted unnecessarily during execution of ALTER TABLE... REORGANIZE PARTITION. (Bug #25675481)

    References: See also: Bug #26735618, Bug #27191468.

  • Race conditions sometimes occurred during asynchronous disconnection and reconnection of the transporter while other threads concurrently inserted signal data into the send buffers, leading to an unplanned shutdown of the cluster.

    As part of the work fixing this issue, the internal templating function used by the Transporter Registry when it prepares a send is refactored to use likely-or-unlikely logic to speed up execution, and to remove a number of duplicate checks for NULL. (Bug #24444908, Bug #25128512)

    References: See also: Bug #20112700.