# Upgrading MariaDB MaxScale From 2.0 to 2.1

## Upgrading MariaDB MaxScale from 2.0 to 2.1

## 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](https://github.com/mariadb-corporation/mariadb-docs/blob/main/en/mariadb-maxscale-2208-maxscale-2208-changelog/README.md).

### Installation

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

### IPv6 Support

MaxScale 2.1.2 added support for IPv6 addresses. The default interface that listeners bind to\
was changed from the IPv4 address `0.0.0.0` to the IPv6 address `::`. To bind to the old IPv4 address,\
add `address=0.0.0.0` to the listener definition.

### Persisted Configuration Files

Starting with MaxScale 2.1, any changes made with the newly added [runtime configuration change](https://mariadb.com/kb/Reference/MaxAdmin#runtime-configuration-changes)\
will be persisted in a configuration file. These files are located in `/var/lib/maxscale/maxscale.cnf.d/`.

### 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 MariaDB 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 MariaDB 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.

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