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Percona Distribution for MySQL 8.4.4 using Percona Server for MySQL (2025-03-18)

Percona Distribution for MySQL is more than just a version of MySQL; it is a comprehensive solution that combines Percona Server for MySQL with additional tools to create a cohesive environment. This distribution is reliable, scalable, and secure, ensuring that all components have been tested to work seamlessly together. You can choose from two download options: one that uses Percona Server for MySQL and another that utilizes Percona XtraDB Cluster. Refer to Install Percona Distribution for MySQL.

This release is based on Percona Server for MySQL 8.4.4-4 that includes all the features and bug fixes available in the MySQL 8.4.4 Community Edition and enterprise-grade features developed by Percona.

Release highlights

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 variable, 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.

  • Improves the behavior of audit_log_filter_set_user to support wildcards in the hostname.

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.

Known issues

  • ProxySQL contains counters that have not been updated to use the new terminology. Unexpected results may occur. In an 8.4.x environment, the binlog reader errors out during initialization due to the use of old terminology, such as the SHOW MASTER STATUS command.

Supplied components

Review each component’s release notes for What’s new, improvements, or bug fixes. The following is a list of the components supplied with the Percona Server for MySQL-based variation of the Percona Distribution for MySQL.

Component Version Description
Orchestrator 3.2.6-16 The replication topology manager for Percona Server for MySQL
ProxySQL 2.7.1-1 A high performance, high-availability, protocol-aware proxy for MySQL
Percona Toolkit 3.7.0 The set of scripts to simplify and optimize database operation.
Percona XtraBackup 8.4.0-2 An open-source hot backup utility for MySQL-based servers
MySQL Shell 8.4.4 An advanced client and code editor for MySQL Server
MySQL Router 8.4.4 Lightweight middleware that provides transparent routing between your application and back-end MySQL servers