Difference between revisions of "MariaDB/MySQL"
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:The replicate-do-db specifies for which database the binlog on the master is read, one line per database. If omitted for all databases binlog is read. | :The replicate-do-db specifies for which database the binlog on the master is read, one line per database. If omitted for all databases binlog is read. | ||
server-id=2 | server-id=2 | ||
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replicate-do-db=exampledb | replicate-do-db=exampledb | ||
Revision as of 22:12, 21 October 2019
MariaDB is an open source fork of MySQL. There are some differences but most are internal, for users the commands and SQL syntax is exactly the same.
phpMyAdmin is a web based GUI for the maintenance of MariaDB and MySQL servers.
Move users from one server to another
Starting on the source server execute this script
PASSWORD=$1
mysql -B -N -uroot -p${PASSWORD} -e "SELECT CONCAT('\'', user,'\'@\'', host, '\'') FROM user WHERE user IN ('username1', 'username2', 'username3')" > users.txt
while read line
do
mysql -B -N -uroot -p${PASSWORD} -e "SHOW GRANTS FOR $line"
done < users.txt > users.sql
sed -i 's/$/;/' users.sql
Move the file to the other server and there do:
mysql -u root -p < users.sql
Set up replication
With replication all transactions on the master database server are immediately replicated to the slave database server. So you create a hot copy of the database that can be used in case of a failure of the master server or to offload the master server by executing retrieval queries on the slave.
This procedure is a found on howtoforge.com [1]
On the master
- Edit the my.cnf so it has below lines.
- The server must be accessible from the slave server and the server-id must be unique in you network
- The binlog-do-db specifies for which database the binlog is written, one line per database. If omitted for all databases binlog is written.
#skip-networking #bind-address = 127.0.0.1 log-bin = /var/log/mysql/mysql-bin.log binlog-do-db=exampledb server-id=1
- Restart the database server
/etc/init.d/mysql restart
- Create a replication user
mysql -uroot -p mysql> GRANT REPLICATION SLAVE ON *.* TO 'slave_user'@'%' IDENTIFIED BY '<some_password>'; mysql> FLUSH PRIVILEGES;
mysql> USE exampledb; mysql> FLUSH TABLES WITH READ LOCK; mysql> SHOW MASTER STATUS; +---------------+----------+--------------+------------------+ | File | Position | Binlog_do_db | Binlog_ignore_db | +---------------+----------+--------------+------------------+ | mysql-bin.006 | 183 | exampledb | | +---------------+----------+--------------+------------------+ 1 row in set (0.00 sec)
- Dump the database
mysqldump -u root -p<password> --opt exampledb > exampledb.sql
- Unlock the tables
mysql -u root -p<password> mysql>UNLOCK TABLES; mysql> quit;
On the slave server
- Create the slave database
mysql -u root -p mysql> CREATE DATABASE exampledb; mysql> quit;
- Load the database dump created on the master
mysql -u root -p<password> exampledb < /path/to/exampledb.sql
- Edit the my.cnf so it has these lines
- The server-id must be unique in you network
- The replicate-do-db specifies for which database the binlog on the master is read, one line per database. If omitted for all databases binlog is read.
server-id=2 replicate-do-db=exampledb
- Restart the database server
/etc/init.d/mysql restart
In the following statement the values from SHOW MASTER STATUS above must be used.
mysql -u root -p<password> mysql> SLAVE STOP; mysql> CHANGE MASTER TO MASTER_HOST=<masterIP>, MASTER_USER='slave_user', MASTER_PASSWORD='<password>', MASTER_LOG_FILE='mysql-bin.006', MASTER_LOG_POS=183; mysql> SLAVE START; mysql> quit;