====== MySQL : Mutualisation de bases de données ======

**Utilisation et configuration multiples bases mysql sur une même machine**


==== cas de vmps60 par exemple: ====

Il faut commencer par créer les répertoires de chaque bases de données supplémentaires puis les initialiser avec la commande mysql_install_db 

<code bash>
mkdir /var/lib/mysql-databases/mysqld2

mkdir /var/lib/mysql-databases/mysqld3

mkdir /var/lib/mysql-databases/mysqld4
</code>
\\ 


==== Configuration du fichier my.cnf ====

Ajouter le paragraphe mysqld_multi

----

<code>
[mysqld_multi]
mysqld     = /usr/bin/mysqld_safe
mysqladmin = /usr/bin/mysqladmin
log        = /var/log/mysqld_multi.log
user       = multi_admin
password   = multipass

# If you want to use mysqld_multi uncomment 1 or more mysqld sections
# below or add your own ones.

# WARNING
# --------
# If you uncomment mysqld1 than make absolutely sure, that database mysql,
# configured above, is not started.  This may result in corrupted data!

[mysqld1]
port       = 3306
datadir    = /var/lib/mysql
pid-file   = /var/lib/mysql/mysqld.pid
socket     = /var/lib/mysql/mysql.sock
user       = mysql

[mysqld2]
port       = 3307
datadir    = /var/lib/mysql-databases/mysqld2
pid-file   = /var/lib/mysql-databases/mysqld2/mysql.pid
socket     = /var/lib/mysql-databases/mysqld2/mysql.sock
user       = mysql

[mysqld3]
port       = 3308
datadir    = /var/lib/mysql-databases/mysqld3
pid-file   = /var/lib/mysql-databases/mysqld3/mysql.pid
socket     = /var/lib/mysql-databases/mysqld3/mysql.sock
user       = mysql

[mysqld4]
port       = 3309
datadir    = /var/lib/mysql-databases/mysqld4
pid-file   = /var/lib/mysql-databases/mysqld4/mysql.pid
socket     = /var/lib/mysql-databases/mysqld4/mysql.sock
user       = mysql
</code>

----


==== Connexion sur une base ( par exemple mysqld4 ) ====

<code bash>mysql -p -P 3309 -S /var/lib/mysql-databases/mysqld4/mysql.sock</code>

Sur chaque base il faut créer l'utilisateur qui a les droits d’arrêter la base :

<code bash>vmps60:/etc/rc.d# mysql -p -P 3309 -S /var/lib/mysql-databases/mysqld4/mysql.sock
Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.5.33 SUSE MySQL package

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> GRANT SHUTDOWN ON *.* TO multi_admin@localhost IDENTIFIED BY 'multipass';
</code>

utilisation :
<code bash>
vmps60:/etc/rc.d# mysqld_multi report

Reporting MySQL servers
MySQL server from group: mysqld1 is running
MySQL server from group: mysqld2 is running
MySQL server from group: mysqld3 is running
MySQL server from group: mysqld4 is running
</code>

Arret de la base mysqld4 :
<code bash>
vmps60:/etc/rc.d# mysqld_multi stop 4

vmps60:/etc/rcd # mysqld_multi report

Reporting MySQL servers
MySQL server from group: mysqld1 is running
MySQL server from group: mysqld2 is running
MySQL server from group: mysqld3 is running
MySQL server from group: mysqld4 is not running
</code>

Démarrage de la base 4
<code bash>
vmps60:/etc/rc.d# mysqld_multi start 4

vmps60:/etc/rc.d# mysqld_multi report

Reporting MySQL servers
MySQL server from group: mysqld1 is running
MySQL server from group: mysqld2 is running
MySQL server from group: mysqld3 is running
MySQL server from group: mysqld4 is running
</code>