3 Changes in MySQL NDB Cluster 8.4.7 (2025-10-24, LTS Release)

MySQL NDB Cluster 8.4.7 is a new LTS release of NDB 8.4, based on MySQL Server 8.4 and including features in version 8.4 of the NDB storage engine, as well as fixing recently discovered bugs in previous NDB Cluster releases.

Obtaining MySQL NDB Cluster 8.4. NDB Cluster 8.4 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/.

For an overview of major changes made in NDB Cluster 8.4, see What is New in MySQL NDB Cluster 8.4.

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 8.4 through MySQL 8.4.7 (see Changes in MySQL 8.4.7 (2025-10-21, LTS Release)).

Note

These release notes were created with the assistance of MySQL HeatWave GenAI.

Functionality Added or Changed

Data node logging is improved with the following:
- Local logs for data node join and leave events.
- API disconnection handling logs.
(Bug #38414245)
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)
When running CREATE or INSERT statements on a NDB Binlog server with sql_log_bin = 0, replication would fail due to a table not existing. (Bug #37953883)
Concurrent execution of TRUNCATE TABLE statements and starting an Ndb backup could cause the statements to hang indefinitely, affecting cluster availability. Errors were returned similar to the following:
```
        ERROR 1296 (HY000): Got error 761 'Unable to drop table as
        backup is in progress' from NDBCLUSTER
      
```
(Bug #37486661)
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)
The MySQL NDB Cluster's example code for MGMAPI_LOGEVENT was intended to compile as plain C, but had a .cpp extension and included a C++ header. The example file has been renamed to main.c and the C++ header has been removed. (Bug #12678874)