Switching Between Different Installed MariaDB Versions

Techniques for managing parallel installations of different MariaDB versions, typically using symlinks and separate data directories for testing.

This article is about managing many different installed MariaDB versions and running them one at a time. This is useful when doing benchmarking, testing, or for when developing different MariaDB versions.

This is most easily done using the tar files from mariadb.org/download/.

Stopping a Preinstalled MySQL/MariaDB From Interfering With Your Tests

If MySQL/MariaDB is already installed and running, you have two options:

1. Use test MariaDB servers with a different port & socket.

• In this case you are probably best off creating a specific section for MariaDB in your ~/.my.cnf file.

1. Stop mysqld with /etc/rc.d/mysql stop or mariadb-admin shutdown.

Note that you don't have to uninstall or otherwise remove MySQL!

How to Create a Binary Distribution (tar File)

Here is a short description of how to generate a tar file from a source distribution. If you have downloaded a binary tar file, you can skip this section.

The steps to create a binary tar file are:

• Decide where to put the source. A good place is under /usr/local/src/mariadb-5.#.

• Get the source

• Compile the source

• Create the binary tar ball.

You will then be left with a tar file named something like:mariadb-11.0.1-MariaDB-linux-x86_64.tar.gz

Creating a Directory Structure for the Different Installations

Install the binary tar files under /usr/local/ with the following directory names (one for each MariaDB version you want to use), for example:

• mariadb-10.5

• mariadb-10.6

• mariadb-10.11

• mariadb-11.0

• mariadb-11.1

The above assumes you are just testing major versions of MariaDB. If you are testing specific versions, use directory names like mariadb-11.0.1

With the directories in place, create a symlink named mariadb which points at the mariadb-XXX directory you are currently testing. When you want to switch to testing a different version, just update the symlink.

Example:

cd /usr/local
tar xfz /tmp/mariadb-11.0.1-linux-systemd-x86_64.tar.gz
mv -vi mariadb-11.0.1-MariaDB-systemd-linux-x86_64 mariadb-11.0
ln -vs mariadb-11.0 mariadb

Setting Up the Data Directory

When setting up the data directory, you have the option of either using a shared database directory or creating a unique database directory for each server version. For testing, a common directory is probably easiest. Note that you can only have one mysqld server running against one data directory.

Setting Up a Common Data Directory

The steps are:

1. Create the mysql system user if you don't have it already! (On Linux you do it with the useradd command).

2. Create the directory (we call it mariadb-data in the example below) or add a symlink to a directory which is in some other place.

3. Create the mysql permission tables with mariadb-install-db.

cd /usr/local/
mkdir mariadb-data
cd mariadb
./bin/mariadb-install-db --no-defaults --datadir=/usr/local/mariadb-data
chown -R mysql mariadb-data mariadb-data/*

The reason to use --no-defaults is to ensure that we don't inherit incorrect options from some old my.cnf.

Setting Up Different Data Directories

To create a different data directories for each installation:

cd mariadb
./scripts/mariadb-install-db --no-defaults
chown -R mysql mariadb-data mariadb-data/*

This will create a directory data inside the current directory.

If you want to use another disk, you should run this command:

cd mariadb
ln -s path-to-empty-directory-for-data data
./scripts/mariadb-install-db --no-defaults --datadir=./data
chown -R mysql mariadb-data mariadb-data/*

Running a MariaDB Server

The normal steps are:

rm mariadb
ln -s mariadb-# mariadb
cd mariadb
./bin/mysqld_safe --no-defaults --datadir=/usr/local/mariadb-data &

Setting Up a .my.cnf file for Running Multiple MariaDB Versions

If you are going to start/stop MariaDB a lot of times, you should create a ~/.my.cnf file for the common options you are using.

The following example shows how to use a non-standard TCP-port and socket (to not interfere with a main MySQL/MariaDB server) and how to setup different options for each main server:

[client-server]
socket=/tmp/mysql.sock
port=3306
[mysqld]
datadir=/usr/local/mariadb-data

[mariadb-11.0]
# Options for MariaDB 11.0
[mariadb-11.1]
# Options for MariaDB 11.1

If you create an ~/.my.cnf file, you should startmysqld with --defaults-file=~/.my.cnf instead of --no-defaults in the examples above.

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