Upgrading MariaDB MaxScale from 2.0 to 2.1

This document describes particular issues to take into account when upgrading MariaDB MaxScale from version 2.0 to 2.1.

For more information about MariaDB MaxScale 2.1, please refer to the ChangeLog.

For a complete list of changes in MaxScale 2.1.0, refer to the MaxScale 2.1.0 Release Notes.

Installation

Before starting the upgrade, we strongly recommend you back up your current configuration file.

MaxScale Log Files

The name of the log file was changed from maxscaleN.log to maxscale.log. The default location for the log file is /var/log/maxscale/maxscale.log.

Rotating the log files will cause MaxScale to reopen the file instead of renaming them. This makes the MaxScale logging facility logrotate compatible.

ReadWriteSplit

The disable_sescmd_history option is now enabled by default. This means that slaves will not be recovered mid-session even if a replacement slave is available. To enable the legacy behavior, add the disable_sescmd_history=true parameter to the service definition.

Persistent Connections

The MySQL session state is reset in MaxScale 2.1 for persistent connections. This means that any modifications to the session state (default database, user variable etc.) will not survive if the connection is put into the connection pool. For most users, this is the expected behavior.

User Data Cache

The location of the MySQL user data cache was moved from /var/cache/maxscale/<Service> to /var/cache/maxscale/<Service>/<Listener>.

Galeramon Monitoring Algorithm

Galeramon will assign the master status only to the node which has a wsrep_local_index value of 0. This will guarantee consistent writes with multiple MaxScales but it also causes slower changes of the master node.

To enable the legacy behavior, add root_node_as_master=false to the Galera monitor configuration.

MaxAdmin Editing Mode

The default editing mode was changed from vim to emacs mode. To start maxadmin in the legacy mode, use the -i option.