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Percona XtraDB Cluster 8.4.4-4 (2025-04-16)

Percona XtraDB Cluster (PXC) supports critical business applications in both cloud and on-premises environments, including public, private, and hybrid setups. Our free, open source, enterprise-grade solution includes the high availability and security features your business requires to meet your customer expectations and business goals.

Release highlights

Percona XtraDB Cluster 8.4.4-4 is based on Percona Server for MySQL and includes all improvements and bug fixes available in the Percona Server for MySQL 8.4.4-4 (2024-12-18) release notes.

Percona XtraDB Cluster 8.4.4-4

Implements the Clone plugin for State Snapshot Transfer (SST) Method. The Clone SST is a modern and efficient method that leverages MySQL’s native cloning capabilities to transfer data from a donor node to a Joiner node. It is faster and more resource-efficient compared to traditional methods like xtrabackup or rsync.

Percona Server for MySQL 8.4.4-4

Improves the Data masking performance by introducing an internal term cache. The new cache speeds up lookups for gen_blocklist() and gen_dictionary() functions by storing dictionary data in memory. However, if the dictionary table is modified directly (outside of the proper functions), the cache may become out of sync. To fix this, use the new masking_dictionaries_flush() function.

Changes also affect row-based replication: dictionary changes on the source server are replicated, but the term cache on the replica doesn’t update immediately. To address this, a new system setting, component_masking_functions.dictionaries_flush_interval_seconds(), can be set to automatically refresh the cache at specified intervals, helping replicas stay in sync.

Find more detailed information in the Data masking overview and in the Data masking component functions.

MySQL 8.4.4

Improvements and bug fixes introduced by Oracle for MySQL 8.4.4 and included in Percona Server for MySQL are the following:

  • Fixed an assertion in debug builds where certain IO buffer serializations caused system hangs. (Bug #37139618)

  • Resolved a failure when dropping the primary key and adding a new AUTO_INCREMENT column as the primary key in descending order using the INPLACE algorithm resulted in failure. (Bug #36658450)

  • Fixed incorrect results, including missing rows, in queries that used a descending primary key with the index_merge optimization. (Bug #106207, Bug #33767814)

  • Addressed a replication channel issue where MySQL failed to stop the channel properly when large transactions were being processed, and STOP REPLICA was requested. This issue also prevented graceful server shutdown, requiring process termination or system restart. (Bug #115966, Bug #37008345)

Find the complete list of bug fixes and changes in the MySQL 8.4.4 release notes.

Improvements

PXC-4469: Implements the Clone plugin for State Snapshot Transfer (SST) Method.

Bug fixes

  • PXC-4173: The Percona XtraDB Cluster node stalled when parallel replication workers executed Data Definition Language (DDL) through an asynchronous node.

  • PXC-4390: The wsrep_group_commit_queue option was removed because caused deadlock bugs.

  • PXC-4498: The Percona XtraDB Cluster node stalled and caused the cluster to stop responding.

  • PXC-4393: When a donor pipeline had more than two commands, only the final command’s failure was registered. However, the error message incorrectly pointed to the second-to-last command.

  • PXC-4404: Setting the wsrep_preordered=ON option caused protocol violations.

  • PXC-4504: The DROP PROCEDURE/FUNCTION IF EXISTS option generated a local Global Transaction Identifier (GTID) event.

  • PXC-4573: The mysql.pxc.sst.role lacked the INNODB_REDO_LOG_ARCHIVE privilege when the State Snapshot Transfer (SST) required InnoDB redo log archiving.