MySQL NDB Cluster 9.5 Release Notes

2 Changes in MySQL NDB Cluster 9.5.0 (2025-10-23, Innovation Release)

MySQL NDB Cluster 9.5.0 is a new Innovation release of NDB Cluster, based on MySQL Server 9.5 and including features in version 9.5 of the NDB storage engine, as well as fixing recently discovered bugs in previous NDB Cluster releases.

Obtaining MySQL NDB Cluster 9.5.  NDB Cluster 9.5 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/.

For an overview of major changes made in NDB Cluster 9.5, see What is New in MySQL NDB Cluster 9.5.

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 9 through MySQL 9.5.0 (see Section 2, “Changes in MySQL NDB Cluster 9.5.0 (2025-10-23, Innovation Release)”).

Deprecation and Removal Notes

  • Support for Ndb.cfg configuration files, deprecated in MySQL 9.1, has been removed; such files are no longer read by any NDB Cluster executable.

    For further information, see NDB Cluster Connection Strings. (WL #16302)

Functionality Added or Changed

  • MySQL NDB Cluster now generates log entries for redo logging issues, including redo log buffer exhaustion, redo log space exhaustion, and file change problems, which can cause transactions to be aborted, queued, or delayed. A secondary overload control mechanism monitors the rate at which the redo log part's Redo buffer is flushed to disk and estimates the time required to complete writing all data in the part's Redo buffer. (Bug #37903091)

  • LogLevelBackup and LogLevelSchema Data node options were added in this release. (Bug #28004136)

Bugs Fixed

  • If a data node restarted during a backup, the remaining data nodes could hang and the backup process stopped. The backup was marked as failed, and other nodes did not terminate their backup process, preventing further backups from being initiated. (Bug #38316252)

  • It was not possible to restore backups with BackupID values greater than 2147483647, with the ndb_restore tool. Errors were returned similar to the following: 

            ndb_restore: [Warning] option 'backupid': signed value
        3000000000 adjusted to 2147483647. Failed to find backup
        2147483647.

    (Bug #38260769)

  • Setting log level options for data nodes in MySQL NDB Cluster, such as LogLevelCheckpoint, LogLevelStatistic, LogLevelInfo, LogLevelCongestion, LogLevelError, and LogLevelConnection to a higher value does not provide additional log information beyond their default values. Errors were returned similar to the following: 

            Ndb kernel thread 0 is stuck in: Job Handling elapsed=100,
        Watchdog: Warning overslept

    (Bug #17847063)

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