Release Notes for MariaDB MaxScale 6.4.4


MariaDB MaxScale is an advanced database proxy and query router.

MariaDB MaxScale 6.4.4 was released on 2022-11-29. This release is of General Availability (GA) maturity.

Issues Fixed

Can result in a hang or crash

  • When Schema Router (schemarouter) is used, authentication failures during shard mapping are not handled correctly. (MXS-4393)

    • In previous releases, schemarouter does not process the error, which causes the shard mapping to hang if the failing server was the last one to return a response.

    • Starting with this release, schemarouter ignores a server when it responds with an error.

  • When Schema Router (schemarouter) is used, errors can cause MaxScale to crash due to a race condition in the router's error handler. (MXS-4389)

  • When the LOAD DATA LOCAL INFILE statement is executed and autocommit is changed, the session can hang until timeout occurs. (MXS-4388)

Can result in unexpected behavior

  • In binary packages, librdkafka is built without SASL support enabled, which impacts the Kafka CDC Router (kafkacdc) and the Kafka Importer Router (kafkaimporter). (MXS-4348)

  • When smartrouter cancels a query, it can cancel the wrong query. (MXS-4317)

  • When using the MaxScale REST API, the /maxscale/logs/data endpoint does not filter syslog contents correctly. (MXS-4353)

  • When an UPDATE statement references a user-defined variable, MaxScale's query classifier classifies the statement as a read statement, which can cause the statement to be routed to a replica server and can break replication (MXS-4413)

  • When the Kafka CDC Router (kafkacdc) is used, disk utilization is high. (MXS-4404)

    • In previous releases, kafkacdc truncates the current_gtid.txt file every time the router processes a GTID event.

    • Starting with this release, kafkacdc updates the current_gtid.txt file more efficiently by keeping the file handle open and writing the GTID to the file as a null-terminated string, which allows truncation to be avoided.

  • When the fields[] and filter query parameters are both used with the REST API, all results could be improperly removed by the filter. (MXS-4397)

  • When MaxScale is configured to read database grants from a file using the user_accounts_file parameter and the user_accounts_file_usage parameter is set to file_only_always, MaxScale is not aware of which databases are available. (MXS-3043)

    • In previous releases, the following error is raised with the ER_BAD_DB_ERROR error code:

      Unknown database 'DATABASE_NAME'
    • Starting with this release, when MaxScale reads a database privilege from the user accounts file, it adds the database to its list of known databases.

  • MaxGUI does not use memory efficiently, which can cause the web browser to crash due to an out-of-memory (OOM) condition. (MXS-4372)


In alignment to the MariaDB Corporation Engineering Policy, MariaDB MaxScale 6.4.4 is provided for:

  • CentOS 7 (x86_64)

  • Debian 9 (x86_64, ARM64)

  • Debian 10 (x86_64, ARM64)

  • Debian 11 (x86_64, ARM64)

  • Red Hat Enterprise Linux 7 (x86_64)

  • Red Hat Enterprise Linux 8 (x86_64, ARM64)

  • Red Hat Enterprise Linux 9 (x86_64, ARM64)

  • Rocky Linux 8 (x86_64, ARM64)

  • Rocky Linux 9 (x86_64, ARM64)

  • SUSE Linux Enterprise Server 15 (x86_64, ARM64)

  • Ubuntu 18.04 (x86_64, ARM64)

  • Ubuntu 20.04 (x86_64, ARM64)

  • Ubuntu 22.04 (x86_64, ARM64)