Note: This is an RHCE 7 exam objective.
Presentation of MariaDB
MariaDB is a binary replacement for MySql, the famous database system.
Prerequisites
As the default MariaDB installation uses the /var/lib/mysql directory to store your databases, keep in mind that the partition or logical volume associated with /var needs adequate space.
Installation Procedure
To install it, apply the following steps:
Install the MariaDB packages:
# yum install -y mariadb mariadb-server
Start and activate at boot the MariaDB service:
# systemctl start mariadb && systemctl enable mariadb
Execute the basic setup:
# mysql_secure_installation /usr/bin/mysql_secure_installation: line 379: find_mysql_client: command not found NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY! In order to log into MariaDB to secure it, we'll need the current password for the root user. If you've just installed MariaDB, and you haven't set the root password yet, the password will be blank, so you should just press enter here. Enter current password for root (enter for none):type enterOK, successfully used password, moving on... Setting the root password ensures that nobody can log into the MariaDB root user without the proper authorisation. Set root password? [Y/n] Y New password:your-passwordRe-enter new password:your-passwordPassword updated successfully! Reloading privilege tables.. ... Success! By default, a MariaDB installation has an anonymous user, allowing anyone to log into MariaDB without having to have a user account created for them. This is intended only for testing, and to make the installation go a bit smoother. You should remove them before moving into a production environment. Remove anonymous users? [Y/n] Y ... Success! Normally, root should only be allowed to connect from 'localhost'. This ensures that someone cannot guess at the root password from the network. Disallow root login remotely? [Y/n] Y ... Success! By default, MariaDB comes with a database named 'test' that anyone can access. This is also intended only for testing, and should be removed before moving into a production environment. Remove test database and access to it? [Y/n] Y - Dropping test database... ... Success! - Removing privileges on test database... ... Success! Reloading the privilege tables will ensure that all changes made so far will take effect immediately. Reload privilege tables now? [Y/n] Y ... Success! Cleaning up... All done! If you've completed all of the above steps, your MariaDB installation should now be secure. Thanks for using MariaDB!
If you need to access the database from a different server, add the MySql service to the firewall configuration and reload it:
# firewall-cmd --permanent --add-service=mysql success # firewall-cmd --reload success
Initial Configuration
To help you define the initial configuration according to the specifications of your system (memory size, number of CPU, type of activity, etc), you can find useful examples of my.cnf files in the mariadb-server package:
# rpm -ql mariadb-server | grep my- /usr/share/mysql/my-huge.cnf /usr/share/mysql/my-innodb-heavy-4G.cnf /usr/share/mysql/my-large.cnf /usr/share/mysql/my-medium.cnf /usr/share/mysql/my-small.cnf
Start by reading the /usr/share/mysql/my-innodb-heavy-4G.cnf file because it is full of useful comments.
Then, download Major Hayden’s mysqltuner.pl. After running this script, you will get a rough evaluation of your configuration and basic recommentations to improve it.
The innotop package contains a command with the same name that behaves like the top command on MariaDB servers, providing a lot of details about the current activity (cache, locks, replication status, etc). This package is available in the EPEL repository.
Configuration Tip
To get an explanation of all the server options, all the configuration parameters and their current values, type:
# /usr/libexec/mysqld –verbose –help /usr/libexec/mysqld Ver 5.5.52-MariaDB for Linux on x86_64 (MariaDB Server) Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others. Starts the MariaDB database server. Usage: /usr/libexec/mysqld [OPTIONS] Default options are read from the following files in the given order: /etc/mysql/my.cnf /etc/my.cnf ~/.my.cnf The following groups are read: mysqld server mysqld-5.5 mariadb mariadb-5.5 client-server The following options may be given as the first argument: --print-defaults Print the program argument list and exit. --no-defaults Don't read default options from any option file. --defaults-file=# Only read default options from the given file #. --defaults-extra-file=# Read this file after the global files are read. --allow-suspicious-udfs Allows use of UDFs consisting of only one symbol xxx() without corresponding xxx_init() or xxx_deinit(). That also means that one can load any function from any library, for example exit() from libc.so -a, --ansi Use ANSI SQL syntax instead of MySQL syntax. This mode will also set transaction isolation level 'serializable'. --archive[=name] Enable or disable ARCHIVE plugin. Possible values are ON, OFF, FORCE (don't start if the plugin fails to load). ... --xtradb-admin-command[=name] Enable or disable XTRADB_ADMIN_COMMAND plugin. Possible values are ON, OFF, FORCE (don't start if the plugin fails to load). Variables (--variable-name=value) and boolean options {FALSE|TRUE} Value (after reading options) ------------------------------------------------- ------------------------ allow-suspicious-udfs FALSE archive ON aria ON aria-block-size 8192 aria-checkpoint-interval 30 aria-checkpoint-log-activity 1048576 aria-force-start-after-recovery-failures 0 aria-group-commit none ... verbose TRUE wait-timeout 28800 xtradb-admin-command ON To see what values a running MySQL server is using, type 'mysqladmin variables' instead of 'mysqld --verbose --help'.
Additional Resources
Additional information about the transition from MySQL to MariaDB is available on Kolbe’s blog.
Rackspace offers an interesting tutorial about installing a MariaDB server on CentOS.
Carla Schroder’s blog provides some thought about which type of file system to choose and what are the best parameters to set performance-wise.
A presentation about database performance tuning was given at the 2015 Red hat Summit (the associated slides are there).
The linuxpitstop website provides some tips to improve MariaDB performance.
If you are more interested in Oracle products, Red Hat wrote a document about Deploying Oracle RAC Database 12c on RHEL 7.
You can also watch Andrew Mallett‘s video about Installing MariaDB (6min/2015).
Ramesh Natarajan provides an interesting tutorial on How to Move your MySQL Data Directory to a New Location.
The Digital Ocean website has got a tutorial on How to Change a MariaDB Data Directory to a New Location on CentOS 7.
The askapache website offers a tutorial on how to compile MariaDB with LZ4 compression.
You can also read this tutorial about configuring MariaDB SSL and securing client connections.
The Tecmint website wrote an article about 15 Useful MySQL/MariaDB Performance Tuning and Optimization Tips.
The Howtoforge website explains how to enable SSL and remote connections for MySQL on CentOS 7 and how to set up a MySQL multi-master replication.
The Servercheap website provides a tutorial on how to setup remote and secure connections for MySQL on CentOS 7.
Colin Charles gave a presentation at the CentOS Dojo Brussels 2018 about Understanding the MySQL Database ecosystem (48min/2018).
The MySQL High Availability website provides many articles about MySQL replication.
The Percona website provides many interesting articles about MariaDB:
- MariaDB: Selective binary logs events,
- Log rotate and the (deleted) MySQL log file mystery,
- Using YUM to install specific MySQL/Percona Server versions,
- MySQL Auditing with MariaDB Auditing Plugin,
- High availability with asynchronous replication… and transparent R/W split,
- MariaDB 10.2 CHECK and DEFAULT clauses,
- A Look at MariaDB Subquery Cache,
- MySQL, –i-am-a-dummy!
- Monitoring Databases: A Product Comparison,
- MySQL and MariaDB Default Configuration Differences,
- MySQL vs. MariaDB: Reality Check,
- Some Notes on MariaDB system-versioned Tables.
The Percona website has got also many interesting articles about MySQL:
- MySQL Point in Time Recovery the Right Way,
- MySQL and Linux Context Switches,
- ZFS from a MySQL perspective,
- InnoDB Page Compression: the Good, the Bad and the Ugly,
- Internal Temporary Tables in MySQL 5.7,
- Hands-On Look at ZFS with MySQL,
- How to Restore MySQL Logical Backup at Maximum Speed,
- Keep Sensitive Data Secure in a Replication Setup,
- Linux OS Tuning for MySQL Database Performance,
- Chunk Change: InnoDB Buffer Pool Resizing,
- Why MySQL Stored Procedures, Functions and Triggers Are Bad For Performance,
- MySQL 8: Load Fine Tuning With Resource Groups,
- How To Fix MySQL Replication After an Incompatible DDL Command,
- Instrumenting Read Only Transactions in InnoDB,
- The Importance of mysqlbinlog –version,
- Persistence of autoinc fixed in MySQL 8.0,
- TasksMax: Another Setting That Can Cause MySQL Error Messages.
Also, the ScaleGrid blog provides some interesting articles about MySQL:
- MySQL Replication: Errant Transactions in GTID Based Replication,
- Calculating InnoDB Buffer Pool Size for your MySQL Server,
- Data Integrity and Performance Considerations in MySQL Semisynchronous Replication,
- MySQL High Availability Framework Explained – Part I,
- MySQL High Availability Framework Explained – Part II.
The configuration parameters and descriptions for the mysqld section of my.cnf can also be found this way:
/usr/libexec/mysqld –verbose –help |less
options and descriptions at the top, current settings further down
example:
skip-networking Don’t allow connection with TCP/IP
skip-networking FALSE
To change this to disallow networking – edit the mysqld section of my.cnf as follows:
[mysqld]
…
skip-networking=1
Hope it helps.
Very interesting. I will add it to the tutorial. Thanks.
Thanks for this tip 🙂
I’ve recently met the following method to install mariadb:
“yum groupinstall mariadb mariadb-client”: for the server and
“yum groupinstall mariadb-client” for the client.
I had some issues when installing your way on 7.0 – the “mysql_secure_install” complained some non-sense until I installed the whole group.
So in case “mysql_secure_client” starts complaining – install the whole group.
Interesting but I never had any problem when installing MariaDB whatever the RHEL 7 minor version.
Same here, not a single time I had issues with installing MariaDB on RHEL 7.x. Strange.
hunter86_bg you seem to be having some strange issues. Can you give us more details on the version of RHEL you have. Is it a beta by any chance! Is the system you are using a fresh copy or has it been upgraded? Is it in a virtual environment….?