Upgrading MariaDB MaxScale from 2.5 to 6

This document describes possible issues when upgrading MariaDB MaxScale from version 2.5 to 6.

Note that the versioning scheme has changed and that version 6 immediately follows version 2.5. Effectively, the non-changing 2.-prefix has been dropped and henceforth at a major release, the major, instead of the minor version number, will be bumped. This change also affects how maintenance releases are versioned. For instance, 2.5.1, the first GA version of MaxScale 2.5, was followed by the maintenance release 2.5.2. 6.1, the first GA version of MaxScale 6, will be followed by the maintenance release 6.2.

For more information about MaxScale 6, refer to the ChangeLog.

Before starting the upgrade, any existing configuration files should be backed up.

Duration Type Parameters

Using duration type parameters without an explicit suffix has been deprecated in MaxScale 2.4. In MaxScale 6 they are no longer allowed when used with the REST API or MaxCtrl. This means that any create or alter commands in MaxCtrl that use a duration type parameter must explicitly specify the suffix of the unit.

For example, the following command:

maxctrl alter service My-Service connection_keepalive 30000

should be replaced with:

maxctrl alter service My-Service connection_keepalive 30000ms

Duration type parameters can still be defined in the configuration file without an explicit suffix but this behavior is deprecated. The recommended approach is to add explicit suffixes to all duration type parameters when upgrading to MaxScale 6.

Changed Parameters

threads

The default value of threads was changed to auto.

Removed Parameters

Core Parameters

The following deprecated core parameters have been removed:

• thread_stack_size

Schemarouter

The deprecated aliases for the schemarouter parameters ignore_databases and ignore_databases_regex have been removed. They can be replaced with ignore_tables and ignore_tables_regex.

In addition, the preferred_server parameter that was deprecated in 2.5 has also been removed.

Session Command History

The prune_sescmd_history, max_sescmd_history and disable_sescmd_history have been made into generic service parameters that are shared between all routers that support it.

The default value of prune_sescmd_history was changed from false to true. This was done as most MaxScale installations either benefit from it being enabled or are not affected by it.